What is Galvannealed Steel?   

Galvanneal, also known as galvannealed steel, is a product of galvanizing process before placing the steel under the annealing process. It is easy to identify a galvannealed steel by looking at its color. It has a uniform matte grey color, which absorbs paints quickly compared to galvanized steel. The paint does not adhere and becomes brittle in galvanized steel.

There are many stages involved in the processing of galvannealed sheets. It starts with hot dip galvanization, where the material passes through a galvanizing zinc bath. From there, the steel sheet undergoes air knives to expel excess zinc before heating it for a few seconds in an annealing furnace. This method diffuses the zinc and iron layers to form a zinc-iron alloy at the material’s surface. 

Annealing takes place after galvanizing using a hot strip and zinc still liquid. The galvanizing zinc bath contains more than 0.1 percent aluminum, contributing to iron bonding, and coats the zinc layer. This process requires an annealing temperature range from 500 to 565 degrees Celsius. 

Galvanneal Steel Specification 

Galvanneal steel consists of two coating types: zinc and zinc-iron alloy. The zinc coating comprises fourteen coating designations, while the zinc-iron alloy has four coating designations. Z001 zinc coating and ZF001 zinc-iron alloy coatings have no minimum coating thickness and weight.  

Other zinc coating descriptions include Z90, Z120, Z180, Z275, Z305, Z350, Z450, Z550, Z600, Z700, Z900, and Z1100. They have a corresponding both sides coating weight mass of 90, 120, 180, 275, 305, 350, 450, 500, 550, 600, 700, 900, and 1100 g/m2. 

Each side has a coating weight mass of 30, 36, 60, 94, 110, 120, 154, 170, 190, 204, 238, 316, and 390 g/m2. The total coating weight for both sides ranges from 75 to 975 g/m2.  

Other zinc-iron alloy coating descriptions are ZF75, ZF120, and ZF180, with corresponding both sides coating weights of 75, 120, and 180 g/m2. Each has a corresponding one-side coating weight of 24, 36, and 69 g/m2, with both sides coating weights of 60, 90, and 150 g/m2.

Galvannealed Steel vs. Galvanized Steel 

Both galvanized and galvannealed steel have zinc coating at the mill, which gives them resistance to corrosion and rust. Both sheets of steel undergo a hot dip coating process. 

Their difference is that galvanized steel does not require an additional annealing process. The purpose of annealing is to induce diffusion of the alloys between the steel and molten zinc coating. 

Annealing reinforces the paint adhesion and formability of the steel. The dull matte finish makes the surface adhere to the paint because it has a high absorption ability compared to galvanized steel, which has a spangled finish. 

Both sheets of steel follow the standard of ASTM A 653/A 653M grades. It is easy to spot their difference when it comes to their grades. 

Galvanized steel has a designation of G, such as G40, G60, G30, G90, G100, and G115. Galvannealed’ designated grades start with A, like A40 or A60. The number after the letter signifies the coating weight. For example, G40 means 0.40 per square foot. 

The galvanizing process of a bare steel metal is prone to rusting and corrosion as the iron content is high. The steel undergoes a hot bath at 850 degrees Fahrenheit of liquid zinc solution. After the hot bath, the air knives dispel excess zinc to achieve the coating thickness. The molecular bond between the steel and zinc prevents rust formation on the exterior.  

In galvannealing, the sheet metal undergoes heating at 1050 degrees F annealing oven. This method draws excess iron to the steel’s outermost layers to form an alloy of zinc and iron. The material’s surface becomes more robust due to the high amount of iron on the surface, which makes it resilient and improves paint adherence.

Use of Galvannealed Steel 

The durability of galvannealed steel makes it an excellent material for building bridges, highway signs, fencing, and guardrails. Areas that require less maintenance against rust, heavy use, and corrosion use galvannealed steel. The biggest market for galvanneal is the automobile industry. In the mid-1980s, Chrysler Corporation was the first car manufacturer that used galvannealed sheet steels. 

Ten years later, Ford, Toyota, and Honda began using galvannealed coatings in their vehicles using electro-galvanized and hot dip galvanized coatings. The price differences and car frames influence the variations of galvanneal applications in manufacturing vehicles. Another use of galvannealed steel is building permanent line chute and debris systems.  

Conclusion 

Galvanneal steel last for years due to its corrosive-resistant properties. They require less maintenance because the zinc coating is an inhibitor against rusting and has excellent paint adhesion characteristics.

What is Galfan

Galfan refers to steel with zinc-aluminum coating on its layers to achieve a superior anti-corrosive property. It offers protection to various steel grades compared to steel with a galvanized zinc coating. The coating provides better forming and welding properties to the steel and helps prolong its lifespan.

Steel products with Galfan coating are known for their extraordinary performance compared to galvalume, or galvanized steel. Galfan is a late invention among the most popular substrates in the post-frame industry. However, it is the most resistant to corrosion due to its 95 percent zinc and 5 percent aluminum coatings.

Galfan-coated steel has better adhesive, formability, and weldability properties, enabling a micro-scaled coating structure. These properties make the steel pliable and suitable for deep drawing and painting. Only licensed Galfan manufacturers can produce Galfan brand steel and distribute the products to customers.  

Processing of Galfan Coated Steel

Galfan-coated steel undergoes four stages of processing: forming, welding, joining, and painting. Let’s discuss each step:

Forming

The forming process works similarly with uncoated steel when applying zinc coatings to steel. It does not require extensive modifications except for the surface behavior, which needs changes in lubrication, holding forces, and tooling geometry.

The metal coating acts as a lubricant, working on gentle surface pressure during this stage. The steel’s interface creates a thin intermetallic layer making it resistant to cracking during the forming stages. The coating forms a lamellar microstructure that makes the steel suitable to roll forming, depth drawing, bending, and profiling.

Some factors influence the forming stage of Galfan-coated steels, such as steel grade, component geometry, thickness, surface quality, tool, and metal coating type.

Welding

Welding techniques come in various forms when applying it to metal-coated products. These welding methods are arc, laser, and resistance welding. The welded joints have comparable mechanical properties to non-coated steel and use the same methods as zinc-coated steel.

The coating thickness reduces when applying the Galfan method, wherein it requires a lower welding current, which prolongs the service life of the electrodes.

Resistance welding offers superior results to metal-coated steels. The anti-corrosive properties of the steel with zinc-based coating stay permanently in the area after the spot welding. This method needs a higher electrode force and current than uncoated steels because the layer has lower contact resistance.

A reduced coating thickness decreases the required welding current, while an increased coating thickness requires a higher one. Unnecessary thick coatings in welded applications are not advisable as it does not offer weldability property.  

Laser welding offers better weldability to metal-coated products due to its low heat and narrow welding input. If applying the fusion welding techniques, ensure minimal heat input to limit the metal-coated steel’s heated zone.

During the welding process, the area where the application takes place should have proper ventilation to prevent breathing in welding fumes that can affect your health due to its zinc oxide.  

Joining

Zinc-based coatings suit all types of adhesives, such as polyurethane, acrylic, epoxy, or glue—the adhesive sticks well to the surface of Galfan-coated steel, which protects the joints free from corrosion. 

Adhesion is perfect if there is an absence of impurities and oils on the surface of the steel. Aside from adhesive joining, manufacturers use mechanical joining in Galfan coating. This method uses tab and non-tab methods.  

Painting

Adding color to the final product is for aesthetic appeal and helps improve the anti-corrosion property of Galfan-coated metals. Galfan offers a superior painting substrate to steel.

The steel’s skin passes the surface quality B when the painted surface needs high surface quality. The steel should be free from impurities and oils before applying the paint. Another good option is to use zinc phosphate pre-treatment to the surface for the best coating results. 

The Benefits of Galfan Coating 

Galfan coating offers a lot of benefits to steel products, such as:

1. It adds triple corrosion protection compared to galvanized steel using its alternative coating chemistry and reduces coating weights.
2. It produces sustainable steel products at lower costs. 
3. The zinc bath helps reduce the viscosity of the molten metal. This method lowers coating thicknesses more than traditional zinc-based coatings. 
4. It ensures longevity in large and small projects due to its longer service life. 
5. It offers reliable formability and weldability properties. 
6. Its ductility property is suitable for deep drawing. 

Galfan vs. Galvalume 

Galfan and galvalume are both metallic-coated steels. They differ in their coating process. Galfan undergoes cold rolled steel coating with five percent mischmetal and aluminum and ninety-five percent zinc. Galvalume undergoes a non-stop hot dip process with a glazing of 55 percent aluminum and 43.5 percent zinc with 1.5 percent silicon.

The International Lead Zinc Research Organization created Galfan in 1981, while BIEC International Incorporated developed galvalume in 1972. Galfan might be younger but more resistant to corrosion than galvalume. 

A lighter coating weight guarantees extra corrosion protection to Galfan-coated metals. It is ductile, formable, and weldable compared to galvalume due to its high zinc content. 

Conclusion

Galfan is a popular choice by manufacturers in making white goods and automobile parts. Its superior corrosion property is cost-saving as the project can last long. 

The influence of substrate material on the price of pre-painted aluminum coils: the price of aluminum coils of different materials is different, especially the price of 3004 aluminum-magnesium-manganese alloy aluminum coils is nearly $200/ton higher than that of 1060 and 3003 aluminum coils. The price of coated aluminum coils has a greater impact. If the customer has no clear requirements for the material, it is recommended to choose 3003 aluminum coils as the base material for color-coated aluminum coils. However, if the strength requirements for color-coated aluminum coils are relatively high, it is recommended to choose the more expensive 3004 aluminum coil base material.

The influence of paint thickness on the price of color-coated aluminum coils: color-coated aluminum coils can be divided into two types of coating thickness: single-coated and double-coated. Generally, the thickness of single-coated paint is around 15um, and the paint thickness of double-coated color-coated aluminum coils is 25um. nearby. The price of single-coated prepainted aluminum coils is lower than that of double-coated aluminum coils. If you use it in an indoor environment, you can choose a single-coated aluminum coil. It is more reasonable to choose a double-coated color-coated aluminum coil for an outdoor environment.

The influence of coating materials and brands on the price of color-coated aluminum coils: the price of fluorocarbon paints is higher than that of polyester paints. Usually, the price of fluorocarbon paints is about $400/ton higher. Of course, the service life of fluorocarbon color-coated aluminum coils is longer long.

The influence of the thickness of the aluminum coil on the price of the color-coated aluminum coil: If the thickness of the aluminum coil is too thin, the price of the color-coated aluminum coil is relatively high, because the area of the thinner color-coated aluminum coil under the same tonnage is larger, the more paint is used, and the processing time The longer, so the thickness of the aluminum coil also has a certain impact on the price.

The coating types currently used for PPGI coil include PE, PVDF, SMP, acrylic, PVC, etc.

Polyester(PE) 

The Polyester coating is easy to be processed and formed because of its good adhesion, and the price is relatively cheap. But the other degree of UV resistance and chalking resistance is relatively low. Polyester prepainted steel can be used for the roof of ordinary civil buildings.

SMP

SMP steel plate has better durability, and the cost is higher than the PE coating. Silicone is not as good as PE in terms of adhesion and processing formability to materials,

High durable Polyester (HDP)

It is better than ordinary SMP coatings, and its outdoor weather resistance reaches 16 years. Its flexibility and weather resistance are higher.

PVC

PVC coating has nice anti-chemical and anti-water, and the coasting is relatively thick, which can well protect the substrate.

The PVC coating is rarely used because they pollute the environment.

PVDF

PVDF coatings have great color retention and corrosion resistance. Among the PPGI sheet coating for construction, it is the highest grade.

Acrylic

The comprehensive performance is good, the price is expensive, and it is only used in specific fields (such as containers).

Coating Performance Comparison Table

You need to consider when choosing a primer

1) Adhesion of primer and finish coating

2) Corrosion resistance of primer

 For the back coating, if the color-coated steel sheet is a Single layer, Color coated steel with a back primer plus a back finish coating was selected.

 The primer is of the same variety as the front, and a layer of light color (such as white) polyester is selected for the finish coating.

 If the PPGI steel coil is used as a sandwich panel, a layer of epoxy resin with excellent adhesion and corrosion resistance is sufficient.

Find out in this article how hot-dipped galvanized is processed and its long-lasting benefits to structures.

What is hot-dipped galvanized?

Hot dipped galvanized is a galvanizing method by coating the steel and iron with zinc. The steel enters a hot bath of molten zinc at around 842 degrees Fahrenheit. During this process, the zinc reacts with oxygen after exposure to the atmosphere. 

It leads to the formation of zinc carbonate, which offers rust and corrosion protection to the steel. Hot-dip galvanization offers a superior life cycle and is cost-efficient due to its anti-corrosion properties. 

The critical feature of HDG products is longevity and durability. The first maintenance time of hot-dipped galvanized steel is proportional to the zinc coating thickness. It passes through different processing state that yields zero maintenance in the years to come.

Hot Dipped Galvanized vs. Galvanized

The difference between galvanized and hot-dipped galvanized steel lies in the texture and finishing.

Galvanized materials have sharp and smooth finishing, while hot-dipped galvanized have a rough texture. Galvanization passes through different stages to form a layer of zinc carbonate on the metal surface to protect it from corrosion. 

Hot-dip galvanization undergoes a process to form a pure layer of zinc on the surface, which passes through three stages: preparation, galvanizing, and inspection. 

For your easy understanding, galvanized materials have a sharp and smooth texture, while hot dip galvanized have a rough surface. Hot dipped galvanized materials are less expensive than galvanized materials if you consider their performance and longevity.

Hot-dip galvanized materials are mistaken for more costly than it is. People perceive hot-dipped galvanizing as expensive because it underwent a high-performance coating process.

If you think about its longevity of fifty to seventy years, hot-dipped galvanized is a more inexpensive form of galvanization.  

Hot Dipped Galvanized Process

Hot-dip galvanizing undergoes meticulous stages to develop a metallurgical bond between the steel and zinc. Before the steel goes to the galvanizing kettle, it passes through a four-step cleaning process. 

The steel passes through the caustic tank at 180 degrees Fahrenheit. Immersing the steel in an acidic solution removes the steel’s paint, dirt, grease, oil, and residues. The steel enters the fresh water tank to rinse the acidic cleaning solution. 

It goes to a pickling tank of hot acidic solution at 140 to 145 degrees Fahrenheit to remove the mill scale and then rinsed off. The steel immerses in a flux zinc solution consisting of zinc ammonium chloride at 140 to 170 degrees Fahrenheit. 

Flux provides oxidation on the clean surface once exposed to the air before the steel undergoes galvanization. The flux dries on the surface to adhere and helps in the liquid zinc wetting process. 

Once the surface is debris-free, the steel enters the galvanizing kettle, containing molten zinc at 830 to 850 degrees Fahrenheit. The steel remains in the kettle until it reaches the steel and molten zinc bath temperatures.

A diffusion-reaction occurs when the steel is in direct contact with the molten zinc. The reaction leads to the formation of a metallurgically bonded zinc alloy layer. In some instances, the molten zinc bath is added with lead to encourage bath fluidity. 

Its primary purpose is to limit excess zinc on the steel by improving the drainage properties, easy dross recycling, preventing floating trash, and protecting the galvanizing kettle from irregular heat distribution from the galvanizing burners. 

Removal of residues from the steel ensures that the metal has a pure zinc coating. Dipping the steel in a chromate quench tank is the final step in the hot-dip galvanization process. 

Its purpose is to reduce the steel temperature, prevent a reaction from air exposure, and retains the brightness of the zinc coating during storage.

A quality control team inspects the HDG steel for consistency and fabrication of its component before sending it to a galvanizing machine.

The quality assurance team will check the product for possible factory defects when the galvanizing process is over. They also measure the thickness of the zinc coating.

How long does hot-dip galvanizing last?

The process of hot-dip galvanization is essential in protecting the steel from rusting and corrosion in the harshest environments. It does not require maximum maintenance to last more than fifty years. 

However, its corrosion resistance depends on the type of surroundings and elements that may impact its longevity. According to a study, bare steel’s decomposition rate is 1/30 in the same environment. 

Five factors contribute to the performance of hot-dip galvanized steel: rainfall, humidity, temperature, air salinity, and sulfur dioxide air concentration. 

Dr. Gregory Zhang of Teck Metals Limited developed the accurate global performance data known as the Zinc Coating Life Predictor. Using the TFM chart, the first maintenance for the zinc coating shows that 95 percent of the zinc coating is intact. 

It recommends initial maintenance of the material to prolong the longevity of the structure or application.

The governing specification for hot-dipped galvanized material, ASTM A123, says steel products with over ¼ inch thickness should have 3.9 mils of zinc coating. Steel more than ¼ inch thick can last for 72 to 73 years to first maintenance, even if it has exposure to the harshest environments. 

Hot-dip galvanizing is a complete immersion process after submerging the steel into the acidic solution, pickling solution, flux, and molten zinc. It ensures the exterior and interior sides have a full zinc coating.

This process ensures that no corrosion could occur even in the steel structures’ hollow, tubular, and fastener threads.

Corrosion and rusting happen in the interior and concave parts, painted but without corrosion protection. The interior of hot-dipped galvanized material receives ample protection as condensation and humidity have higher rates. 

Is hot-dip galvanized rustproof?

Yes, hot-dip galvanized steel is rustproof depending on its exposure to specific environments. Its rust and corrosion resistance depends on the thickness of the zinc coating and the harshness of the environmental conditions.

Generally, bare steel products in the same environment have a corrosion rate of 1/30. 

Conclusion 

Have you realized the importance of zinc coating thickness in hot-dipped galvanizing? The protection performance of hot-dipped galvanized materials depends on the thickness of the zinc coating and the corrosion of the harshest environments. Comparing galvanized and HDG materials, HDG is inexpensive in the long run, as the material can last for over seven decades.   

Read more about the differences and functions of galvanized and Galvanneal. 

Galvanneal vs. Galvanized Corrosion

The thickness of the coating on the surface of galvanized steel contributes to its corrosion performance. The zinc-iron coating thickness of galvanneal plays a role in the corrosion and rusting protection of the steel. 

Most of the applications of galvanized steel are for painting after fabrication. The thickness of the zinc-alloy coating on Galvanneal also has a role in protecting against corrosion. 

Product Specifications

Galvanneal and galvanized steels are the same standards, the ASTM A 653/A 653M. The American Society for Testing and Materials (ASTM) designates Galvannealed with an A grade like A60 and A40. 

ASTM designates Galvanized with a G grade like G60 or G40. The number denotes the weight of the coating.

Here is a list of common variations in galvanized steel:

• G30 – .30 ounces of coating per square foot
• G60 – .60 ounces of coating per square foot
• G90 – .90 ounces of coating per square foot

Galvanneal steel compositions:

• Zeta alloy layer-5.2 to 6.1 percent iron and 0.7 percent aluminum
• Delta alloy layer-7.0 to 11.5 percent iron and 3.7 percent aluminum
• Gamma alloy layer-15.8 to 27.7 percent iron and 1.4 percent aluminum

Differences in Appearance and Usage

Galvanized steel has a spangled metallic appearance, while Galvanneal has a dull, gray, and matte surface. Galvanized steel is resilient as the paint coating can withstand saltwater and external elements. 

Galvanized steel has anti-corrosion and anti-rust mechanisms that are useful in making several products that may come in contact with water. It is ideal for homes beside coastal areas. It is available in various forms like galvanized wire or galvanized pipes.  

Building exteriors also use galvanized steel to protect from corrosion and rusting. 

Here are the uses of galvanized steel:

• Body parts of automobiles, trucks, and buses
• Steel frames for houses and buildings
• Household appliances, such as hair dryers, air conditioning casings, and washing machines
• Electronic and computer parts
• Highway signs
• Protective gears
• High tension electrical towers
• Wrought-iron gates, window and door bars
• Metal pails & buckets
• Wall and hanging ornaments
• Window & door coverings
• Utility holes & gutters

Galvanneal steel has more benefits and uses than galvanized steel. The process of Galvanneal is for painting purposes. Its zinc coating is more absorbent than galvanized steel because the paint adheres to its surface. 

The zinc coating of galvanneal is more robust and resistant to scratching. The applications of galvanneal steel depend on the amount of carbon or alloy. 

Galvannealed steel with high-strength, thick and low alloy is a good fit for building structures, deep drawing, marine applications, high-tensile stress conditions, and welding operations. 

Galvannealed with low carbon is ideal for automobile frames. It is prevalent in shipbuilding, construction, transport, and automobile manufacturing. 

Differences in Process

Both Galvanneal and Galvanized have a zinc coating to prevent corrosion and rusting. Although they went through a hot-dip coating process, Galvanneal passed through an annealing process. 

This method aims to diffuse the alloy between the steel and the molten zinc coating. It leads to a lusterless surface than the galvanized steel. The annealing process increases the paint’s adhesion and the galvanneal material’s formability. 

The annealing process takes place in a Galvanneal furnace. The steel strip undergoes reheating at a controlled temperature from 500 degrees C to 600 degrees C for a few seconds. A zinc bath with small aluminum portions is ready for dipping the metal sheet. 

As soon as the strip of metal emerges from the hot bath, the air knives remove the pressurized zinc to get the desired coating weight. The strip goes into the furnace approximately 10 to 15 feet above the knives.

The iron-zinc diffusion-reaction restarts and starts breaking down the layer of iron-zinc aluminum when the temperature rises. Reheating of the strip happens while the zinc is still in its liquefied state. 

The strip undergoes several seconds of heating and ten seconds of soaking. The appearance of Galvanneal becomes dull matte grey when enough iron is diffusing into the coating. 

The galvanization process begins by immersing a steel sheet in molten zinc at 850 degrees F—the zinc layers bond to the steel substrate at a specific molecular level. Zinc offers protection to the strip from oxidation when there is exposure to corrosive elements. 

Differences Between Galvanneal and Galvanized Steel

Galvannealed and galvanized steel have zinc coatings to protect them from corrosion and rust. Both have properties that make them unique, such as coating, appearance, specifications, weldability, etc.

Coating 

The galvanized steel coating is mostly zinc with a small portion of iron, zinc, and aluminum bonding layer. Usually, the bulk composition of the zinc-iron alloy is 90 percent zinc and 10 percent iron. 

The annealing process on the Galvanneal leads to forming three coating layers: zeta, delta, and gamma. The gamma layer has the highest level of iron content. 

The coating of Galvanneal is stronger than the galvanized steel, meaning that the former is more resilient and complex than the latter. During press forming and bending, the coating of Galvanneal cracks and produces powder. 

Appearance 

Galvanized steel looks more attractive than Galvannealed material because it has a shiny texture. Galvanneal passes through an annealing process, leading to a rough, dull, and matte surface.

The annealing process results in a zinc-iron (Zn-Fe) alloy. You can paint, coat, or add finishing to the galvanized steel. Their speckled patterns ensure that there are no identical galvanized pieces.

The matte texture of galvannealed steel is ideal for painting as the paint bonds more than galvanized steel. Galvannealed steel is appropriate if you want a flat paint coating. 

Weldability

The annealing process of Galvanneal is an ideal material in all types of structures as it possesses welding characteristics than the galvanized steel. Galvanneal has an iron coating that makes the steel easier to weld than galvanized material.

The electrical resistance, melting point, and hardness of Galvanneal make the material last for years compared to galvanized steel. 

Paintability

If you want to coat your steel with paint, Galvanneal is a good choice. The surface of Galvanneal has high porosity, making it more paintable than galvanized steel. The dull and gray surface of Galvanneal allows the paint to adhere. 

Formability

The annealing process of galvannealed steel produces a ductile and firm surface, leading to higher formability. The coating of galvanized steel is softer, which results in higher machinability.  

The coating in galvanized steel is softer than Galvanneal. The flexibility and soft layer in galvanized materials are lubricants and quickly get scratched. 

Since the Galvanneal coating is hard, it does not get scratches during transporting and handling. It is easy to stretch and roll according to its application. 

Galvanneal vs. Galvanized Cost

Galvanneal is more costly than galvanized steel because of the additional annealing step. The market demand for Galvanneal is high as it offers many advantages over its galvanized counterpart. 

Although the surface may look dull, Galvanneal can withstand rusting and corrosion. It is easy to form, weld, and coat with paint.  

Conclusion

Have you ever thought about which steel is the best? Learning the difference between Galvanneal and galvanized steels can be tricky because they have good qualities. You have to compare their properties before concluding which one is superior to the other. You still need a professional to guide you in choosing the best steel product.

What is Galvalume Roof? 

Galvalume roof is coated with 55 percent zinc and aluminum alloy with the remaining percentage of silicon. The combination of these chemical elements provides ample protection from oxidation. It works similarly with the galvanized roof. 

The coating on the metal sheet can extend the life of your roof for up to 60 years with minimum repair and maintenance every year. Non-coated metal roofing does not last longer compared to the Galvalume roof. 

The corrosion-resistant characteristics of Galvalume make it an ideal roofing choice if you want to save your dollars.   

What is a Painted Metal Roof?

A painted metal roof is a type of metal sheet with paint coatings. This type of roof is corrosion-resistant and can withstand the elements and sun. The paint coating adds a layer of protection and longevity to your roofing. 

Painted metal roofs are sturdy and insulate your home from UV rays, although it is less effective than Galvalume. Since a painted metal roof is prone to fading, you must repaint it every ten years to extend its life.  We offer durable pre-painted steel coils that you can machine into the painted metal roof.

Comparing the Galvalume vs. Painted Metal Roof

Galvalume roofs and painted metal roofs are both metal roofs. A painted metal roof is coated with paint, while Galvalume has an alloy of zinc, aluminum, and silicone coatings.

The surface of Galvalume has a rough texture, making it easy to absorb heat because it is less reflective, which can help save your monthly electricity consumption. 

Galvalume is less expensive because it requires less maintenance than a painted metal roof. If you live in a coastal area, choose a painted metal roof because it can withstand corrosion from saltwater. 

Galvalume vs. Painted Metal Roof Price

Price comparison between a painted metal roof and a Galvalume roof is essential before building your house. The cost of Galvalume steel is almost the same as the galvanized roof. It is inexpensive compared to the price of a painted metal roof. 

Applying a coat of paint for your metal roof is more costly than coating the top with Galvalume treatment. You have to maintain the color when it fades over time in painted roofing. 

Protection Provided

Both Galvalume and painted metal roofs possess weaknesses and strengths that you must consider before starting a project. If using paint, you can customize the protection for your roof. 

If you live in a coastal area, your painted roof receives extra protection from corrosion due to saltwater. The paint acts as a shield against pests and water. Galvalume does not provide the same security and versatility as a painted roof. 

Longevity

Metal roof panels come in various sizes and forms. If you are looking for a long-lasting roofing system, the best choice is the Galvalume metal roofs. This type of roofing material can last for more than 60 years. It does not require complete maintenance and repair compared to painted metal roofs. 

The color of the Galvalume roof can keep it for years without changing or repainting it. The alloy coating on your Galvalume metal roof can stay up to six decades. Painted metal roofs fade their color quickly due to heat from direct sunlight. 

If you choose this roofing system, you have peace of mind as you do not have to worry about repainting. Paint on your metal roof can only last for less than ten years. Some paint coats can stay up to seven years, depending on the brand and the coat layers. 

Color Options

Are there any color options for both Galvalume and painted metal roofs?

Galvalume roofs might be cost-saving and durable, but it does not provide color options as painted roofs. It is therefore unsuitable for the design and architecture of your home. 

If you are focused on the aesthetic look of your home, the best choice is to install a painted metal roof.

Choosing a painted metal roof allows you to express your aesthetic taste because you can select the color you like. Although costly, painted metal roofs have a variety of color schemes for your satisfaction. 

Energy Efficiency

Another consideration when installing a roofing system in your home is energy efficiency. Customers rate the Galvalume as an energy-star-rated roofing product.

It can reflect ultra-violet rays that prevent your abode from getting too much heat. It works effectively in saving your electricity consumption because you do not have to turn on your air-conditioning unit. 

If you choose painted roofing material, you can customize it by telling your contractor to coat a paint that can reflect UV rays.

There are specific colors that can lessen the effect of UV radiation in your home. Dark colors like red or orange can protect against UV rays radiation. Darker colors are better than lighter colors.

Maintenance

Maintenance of your building materials is vital to save your home from wear and tear. Galvalume requires less maintenance and repair than painted metal roofing. 

The paint may fade from direct sunlight, while Galvalume treatment gives the roof longevity that could last for over 60 years. 

However, the longevity of your roof also depends on how you care for and maintain it. Cleaning the roof is vital to prevent rusting due to dried leaves and insects. 

Drawbacks of Galvalume 

Both Galvalume and painted metals have pros and cons. Corrosion is fast when Galvalume directly contacts metals, such as lead and copper. 

The speed of corrosion is even faster when the Galvalume is in contact with water and moist environments.  

To prevent corrosion, make a regular inspection of your Galvalume roof. Remove the debris from concrete, mortar, and wooden roof decking that can increase breakdown on its surface. 

Galvalume is not ideal roofing material if your house is near the beach. The air blows the salt from the coast that can rust the Galvalume coating.  

It is not good to use Galvalume if you plan to put up a roof over an animal shelter. Animal waste and chicken dungs produce fumes that can damage the coating of your Galvalume roof. 

A painted metal roof works better for this structure. 

Drawbacks of Painted Metal Roof

Fading may occur on painted metal roofs when the paint pigment reacts with substances, elements, water, chemicals, and pollution. It begins with the lightening of the color or change to a specific color. The paint starts to break down, which can lead to color fading. 

The fading is not uniform as some areas are not in direct contact with the same substances. The paint color does not last in an outdoor environment, even if the manufacturer uses a high-quality resin or pigment. 

However, there are methods that you must know to prevent color fading on your roof. Your location may also contribute to the quick deterioration of your painted metal roofs. 

If you live in a dry place like Texas, your painted metal roof quickly fades due to extreme heat in the area than in Chicago. The extreme temperature contributes to the speedy deterioration of your home. Fluctuations of temperature also weaken the paint pigment. 

Coating your roof with a paint of your choice gives you fulfillment. You can repaint your metal roof with a different shade as years go by to keep up with style. The metal roof may last for seven years, but it does not mean that it cannot stay for longer years. 

Minimizing the impact of wear and tear on your painted roof means you have to repaint the area with faded color as part of your yearly maintenance. Although it may sound costly, it can still save a penny if it has regular maintenance.   

Conclusion 

Did you find the answer to which roofing material is best for your home? Both types of roofing materials have their pros and cons. If you don’t have enough budget, Galvalume suits your financial needs. If you focus on the aesthetic appeal of your home, a painted metal roof is the best for your project. 

What is Galvanized Steel?

Galvanized steel is a metal sheet with a zinc oxide coating. The surface can withstand extreme conditions as zinc-oxide provides rust-proofing. Galvanized steel can last for years compared to non-galvanized steel.

Manufacturers use galvanized steel in producing corrosion-resistant pipes, ladders, bolts, nuts, nails, and railings. The zinc coating in steel is a cost-effective way of preserving the quality and durability of steel products.

Hot-dip galvanizing is the most popular method of galvanization, in which the steel and a hot bath of molten zinc coat the steel. This method makes the galvanized sheet last for several decades. Galvanized steel coils and galvanized steel strips are the most common products of the hot-dip galvanizing process.

Building structures that use galvanized steel have saved maintenance costs more than those using stainless or structural steel.

What is Stainless Steel?

Stainless steel refers to steel or ferrous iron with a composition of 11 percent chromium content. Chromium protects the iron from corrosion. It also provides heat-resistant properties to the steel to withstand wear and tear.

There are different types of stainless steel with various designations according to their chemical compositions. Some stainless steel has less than 1.2 percent carbon and alloying elements and 10.5 percent chromium content.

Stainless steel’s anti-corrosive property may not be enough to protect the material from corrosion. Manufacturers add other chemical elements to the steel, such as titanium, manganese, silicon, carbon, or nickel, to strengthen corrosion resistance.

Galvanized Steel vs. Stainless Steel Strength

Galvanized steel has many uses in buildings and structures because it is easy to handle. It is malleable and easy to work with compared to stainless steel. Experts recommend to re-galvanize the galvanized steel after welding. Welding the galvanized steel may burn the zinc coating.

Heating and cooling the stainless steel needs the extra control. Stainless steel is more resistant to corrosion from water and saltwater than galvanized steel. Welders must be extra cautious when matching the stainless steel with filler materials during welding.

Welders should avoid a design that generates friction between two stainless steel products. It leads to the combination of the two stainless products. Stainless steel is heavier in weight than galvanized steel.

You can customize stainless steel into different forms and shapes. Stainless steel has many uses in household appliances, spare parts, display racks, railings, car parts, aviation parts, etc.

Galvanized Steel vs. Stainless Steel Corrosion Resistance

Galvanized steel is coated with zinc oxide, making it resistant to corrosion and extreme environmental condition. It can stand in water but may not be able to withstand saltwater.

Stainless steel may stand water and saltwater, but it becomes degraded when exposed to chlorine. The chlorine may tarnish the surface layer of stainless steel, which leads to rusting. When handling stainless steel in all applications, it should be away from products with chlorine content.

Both types of steel apply to all forms of applications. But when it comes to corrosion resistance, welders recommend stainless steel, especially when the building is close to the sea.

Galvanized Steel vs. Stainless Steel Cost

The price of stainless steel and galvanized steel depends on the cost of fuel, market supply, and demand. The untreated structural steel has similar costs to galvanized steel. However, stainless steel is pricier than its galvanized counterpart.

The cost of the manufacturing process of stainless steel contributes to its high price. Galvanized steel costs more than a few cents per pound compared to regular steel.

The price of stainless steel could be more than four to five times the cost of galvanized steel. Stainless steel’s minimum price is about three dollars per pound. Structural steel is 30 – 80 cents per pound.

The price does not matter if the quality of the steel can last several years. Galvanized steel may last for fifty years if the coating does not fade. Overall, the maintenance can be costly compared to stainless steel.

Galvanized Steel vs. Stainless Steel Weight

Galvanized steel and stainless steel have almost similar weights. Their weight may differ on the zinc coating thickness on the galvanized steel and the amount of alloy in stainless steel. The galvanized steel product’s weight becomes heavier than stainless steel if the zinc coating is thick.

Black steel may increase its weight by up to 15 percent depending on the type, size, length, steel properties, galvanizing temperature, and other factors. Stainless steel becomes heavier when it combines chromium and other metals.

In most cases, galvanized steel has a thin zinc oxide layer, making it lighter than stainless steel.

Can Stainless Steel be Galvanized?

Is there a possibility of galvanizing stainless steel? The answer is no. Although it could galvanize stainless steel, combined with any galvanized steel product is discouraged.

Stainless steel has high corrosion resistance, but if used together with galvanized steel may result in degradation. Corrosion hazards may arise if both steel materials are combined. It also depends on the type of galvanized material.

Hot dipped galvanized steel can stand corrosion compared to electro-polished galvanized steel. However, when exposed to marine or salty areas, hot-dipped galvanized steel may cause rusting when used with stainless steel.

Stainless steel or galvanized for outdoors?

Both galvanized and stainless steel is famous for outdoor uses. Both have different abilities to stand corrosion. But the chemical property of galvanized steel may deteriorate when exposed to the elements.

The zinc oxide may fade away due to prolonged exposure to the sun, which leads to rusting. Stainless steel has more resistance to rusting and corrosion due to its chemical composition. The tensile strength of stainless steel screws is higher than galvanized steel.

Stainless steel is ideal for outdoor use because of its high tensile strength. But galvanized steel can be useful for outdoor applications if the coating is not damaged. Hot dipped galvanized steel can last from 30 to a hundred years if properly maintained.

The zinc coating may last from 35 to 50 years in harshest soil and 75 years or more in less corrosive soil. Other factors may contribute to its deterioration, such as strong winds and extreme temperature.

Is stainless steel or galvanized more rust resistant?

Galvanization of steel and metal products offers surface protection. Galvanization uses electroplating to give passivation of the metal surface to the natural elements or substrate materials.

Corrosive substances do not penetrate the metal layers due to the zinc coating. Galvanized steel could last for years as long as the zinc coating remains on the surface.

Stainless steel is more resistant to rust due to its chromium content. It makes the steel heavier than galvanized steel. Some stainless steel has other alloy compositions, making it more resistant to rust.

Exposure to moisture, water, and saltwater may lead to corrosion and rusting of galvanized steel. Regular maintenance is vital to keep the quality and durability of steel materials.

Conclusion

Did you realize the difference between galvanized steel and stainless steel? Both steel product materials are corrosion resistant. Stainless steel can be expensive, but it can be cost-saving for long-term use. It can stand saltwater and moisture and has higher tensile strength than galvanized steel. If you are confused about which product to purchase, talk to your supplier for a quote.

What is Roll Forming

Roll forming is the result of rolling a long strip of metal sheet or typically in a form of a steel coil. It uses a roll-forming machine that bends the metal in a continuous process to come up with a uniform shape.

The metal strip undergoes a series of rolls attached to several stands. Each roll set performs a step-by-step bending process until the desired shape is achieved. The roll-forming machine is capable of producing various sizes and thicknesses of the desired shapes.

The size variations are obtainable by creating the distances for each roll variable using the computerized or manual operating system.  

Roll Forming Process

The process of roll forming is simple by starting with a large strip or sheet metal coil with a width of 1 to 20 inches and thickness from 0.10 mm to 3.2 mm with uncoiler support.

The metal strip is placed in the machine via an entry guide ensuring proper alignment while it passes through the mill rolls. Each roll set forms a bend in a continuous process to ensure that the strip has achieved its desired form.

These sets of rolls are attached to horizontal parallel shafts on top of each other to a stand support. The roll-formed strip is ready for cutting to length.

Advantages of the Roll Forming

Roll-formed metal sections are lightweight compared to extrusion processes that bear similar forms. The formed metal strips have thinner and stronger walls as they underwent cold state hardening.

The process is fast and takes less effort compared to extrusion. It is perfect for medium to large orders of more than 10,000 composed of repeatable designs and orders. Roll forming can perform various features in metal channel design involving notches, bends, holes, embossing, stamping, labels and knockouts.

In-line fabrication is also allowed in roll-forming. The gradual sequence in the roll forming process produces eye-catching finish and extra tolerance against wear and tear.

What products are roll-formed?

There are two types of metals that can be processed into rolled forming, namely: ferrous and non-ferrous metals.  Ferrous metals refer to a metal that is composed of bivalent iron compound, such as steel, carbon, stainless steel, and galvannealed.

Non-ferrous metals refer to metals that do not have iron compound in their chemical makeup. Examples of non-ferrous metals are aluminum, copper, brass, lead, and composites.

Composites refer to materials that are made out of two or more materials with physical or chemical differences. Lead is commonly used in most types of building materials like gutters, flashing, gutter joints, and roofing metal.

ROLL FORMING DIFFERENT FROM OTHER METAL MANUFACTURING PROCESSES?

Forging vs. Roll Forming

Forging uses very hot forming to manipulate the shape and size of a metal sheet or strip. Roll forming uses cold forming technology to form the intended shape of the coiled metal strip.

There is no heat involved in the roll forming instead it uses mechanical deformation using a roll forming machine. Forging manipulates the metal work pieces by using pressurized blows to obtain the intended shape.

Forging process results in extremely hot temperatures for extrusion and rolling the molten steel. The process involves hammering, rolling and pressing until the form is finally achieved. This method is ideal for attaining customized shapes that cold rolling cannot do.

Extrusion vs. Roll Forming

High volume orders make use of roll forming instead of extrusion as the process is faster and uses a minimal amount of materials. It is cost-saving for large orders. The disadvantage of roll forming is the setup of the die is tedious, which can be costly for small orders.

Extrusion process uses a single metal that is easy to fabricate by using a cylindrical billet placed in a closed cavity. The metal is pushed through a mold of the desired shape or cross-section.  

The extruded metal parts are placed in the oven to undergo an additional aging process before the secondary processes is implemented. Extrusion is suitable for low-volume orders that require single bends.

Casting vs. Roll Forming

Roll forming uses a strip of coiled metal that passes through a rolling machine to produce uniform metal shapes. This process is ideal for high-volume batches that require uniform sizes and shapes for large orders.

Casting is ideal for low-volume batches for small orders. It requires heating the liquid metal until melted. The melted metal is then poured into a container or mold to form the desired shapes.

The mold contains a negative impression of the desired shape until it cools down and gently extracted to produce the formed metal. Casting produces high porosity, but it depends on its application.  

What are the applications for roll-forming?

Roll-formed materials are used in transportation and automotive industries. Examples are reinforcement bars, bumpers, window tracks, vehicle parts, and structural components of cars, trucks, trailers, and ships.

These materials are also used for residential and commercial buildings for elevators, downspouts, slatted wall dividers, trusses, and studs. Highway signs, guardrails and bridge deck reinforcements, helicopter blades, honeycomb seals, and backing rings are made of roll-formed metal strips.

Garden and lawn equipment, farm implements, fence posts, grain bin floors are made of these materials. Other uses of roll-formed materials are HVAC, home appliances, office furniture, solar panel components, refrigerator parts, modular partitions, shelving, and display racks.

What are the types of roll forming processes?

Roll forming comes in various types of processes. It all depends on the forming manufacturing on what method they employ in creating their unique shapes for their metal products. It also depends on the application for the roll-formed products, such as siding, roofing, and tubing.

Among the types of roll forming processes include ring rolling, shape rolling, roll bending, and plate rolling, and flat rolling. Each type uses different types of machines for rolling metals, but the process follows the fundamental steps to create uniform sizes and shapes of roll-formed materials.  

Stud and track, angle, beam, seamless, and wrap are some versions of roll forming machines for various applications.

Conclusion

Did you see the differences between roll forming and other methods of manipulation of metal shapes? Roll forming is suitable for high-volume orders because you can save lots of money even if the process requires extra effort. The finished product is made to perfection compared to molten and forged metals.

In 2021, global steel production capacity will rebound significantly from the previous year.

List of largest steel company in the world

ShapeCut

Address:Carole Park,QLD, 4300, AUSTRALIA

ShapeCUT is an Australian steel profile processing supplier with over 14 cutting machines, over 4000 tonnes of steel stock and the largest cutting bed in Queensland.

With over 25 years of experience in the industry, the company understands the importance of on-time delivery. With the company’s rich inventory, ShapeCUT has the ability to provide high-quality plasma, laser and cutting, as well as value-added services such as drilling and beveling, and can provide customers with complete steel processing services.

The company’s products meet ISO 9001:2015 quality assurance and have memberships with the Australian Industry Group and the Australian Iron and Steel Institute.

Amidco General Trading

Address:Dubai

Amidco General Trading is a UAE-based diversified holding company in the steel, construction, international logistics and tools industries. The company was established in 2011 and is headquartered in the Emirate of Dubai.

The company has offices in commercial centers in Spain, the United Arab Emirates and Turkey. Not only can it better serve customers all over the world, but also provide a wider market scope for the company in global trade in steel, construction, logistics, etc.

Kaempf and Harris Sheet Metal

Address:217A Monroe Avenue,Frederick, MD 21701

With over 70 years of industry experience, Kaempf & Harris has been the most respected and well-known machinery company in the region, delivering exceptional craftsmanship and service to its customers.

The company produces more than 500 tons of metal per year, including aluminum, stainless steel, galvanized steel and other steels. From smaller custom solutions to the most complex design projects, the company is capable of delivering high-quality products.

The company’s team of 60 professional technicians have many years of industry experience, in addition they have fully modern manufacturing technology and more than 15,000 square feet of warehouse, can guarantee on-time delivery of high-quality products.

HOA PHAT GROUP

Address:Hai Ba Trung District, Hanoi

Hoa Phat is a leading industrial manufacturing group in Vietnam. Founded in 1992, it started as a construction machinery trading company. After years of development, the business has gradually expanded to the trading and production of steel pipes, steel, and real estate.

At present, the Group is mainly engaged in the production and export of steel (construction steel, hot-rolled coil) and steel (including steel pipes, galvanized steel). Steel production has become the core of the company’s development, accounting for 90% of the group’s revenue.

Hoa Phat can produce 8 million tons of crude steel every year. It is one of the largest steel producers in Southeast Asia and ranks first in the steel and steel pipe production market share in Vietnam.

leveland-Cliffs

Address:200 Public Square Suite 3300 Cleveland, OH 44114

Cleveland-Cliffs is an independent iron ore mining company in the United States that has been a leader among its peers for many years.

In 2020, Cleveland-Cliffs acquired two prominent U.S. steel companies, and today the company is the largest flat steel company and largest iron ore producer in North America.

The company is independent from mining raw materials to primary processing to final finishing, stamping and hot and cold stamping of steel components. The unique advantage of the company is that it is self-sufficient in raw materials and has sufficient capacity to deliver customers a large number of customized products.

Wenzhou zhheng steel industry .,ltd

Address:wenzhou city, zhejiang Japan

Wenzhou zhheng steel industry .,ltd is a one-stop company specializing in stainless steel pipes and stainless steel grade accessories integrating manufacturing, exporting and

The company has more than 20 years of experience in the field of stainless steel, especially in the special-purpose projects of ultra-long, ultra-thin, ultra-thick or ultra-large various and some heat exchanger tubes and large-diameter tubes.

After years of technical improvement, all products of the company have passed ISO9001 and ISO 14001-2004 certification. The company’s employees are professionally trained to respond quickly to all requests from customers, and can guarantee same-day delivery or shortest delivery time.

SHANGHAI BAOGANG STEEL MANUFACTURING CO.,LTD

Address:Baoshan District, Shanghai

Founded in 2000, Shanghai Baosteel Steel Manufacturing Co., Ltd. is a world-leading modern steel enterprise.

The company owns several major manufacturing bases such as Shanghai Baosteel and Wuhan Qingshan. So far, Baosteel Group ranks second in the world’s listed steel companies in terms of crude steel output, and is one of the most complete carbon steel companies in the world.

Baosteel has a world-class manufacturing level. The company has been actively developing advanced manufacturing technology and energy saving and environmental protection technology, and has established a global service network.

Baosteel’s independently developed new-generation high-strength steel for automobiles, high-grade steel for household appliances, bridge steel and other high-end products are at the international advanced level.

JFE Steel Corporation

Address:1 Kawasaki-cho, Chuo-ku, Chiba 260-0835

JFE Steel is a steel manufacturer engaged in steelmaking, processing iron ore raw materials into steel products, JFE Steel has one of the largest steel production capacity in the world.

JFE Steel has a number of branch plants in Japan, including the coastal steel plant in the east and west of Japan, the Chita plant specializing in the production of steel pipes and tubes, and the Sendai plant mainly producing wire rods.

Each plant has mastered advanced technical capabilities to meet customer requirements for different steel grades, and the company has also reduced its environmental impact by developing new ironmaking processes

JSW

Address:Bandra East,Mumba

JSW Steel has a long history of cooperating with JFE Steel in Japan, enabling JSW to acquire state-of-the-art technology to provide high-value steel products to its customers.

JSW Steel is widely recognized by customers for its excellence in the industry. Some of these recognitions include worldsteel’s Steel Sustainability Champion, CDP’s (2020) Leadership Rating.

Since 2008, JSW Steel has been ranked as the world’s top 15 steel producer by World Steel Dynamics for 13 consecutive years, and at the same time, as a responsible business, JSW Steel has been insisting on low carbon production.

Inter World Steel Mills Indonesia

Address:Daerah Khusus Ibukota Jakarta 10610

Inter World Steel Mills Indonesia is an Indonesian steel company that produces strip steel. The company was established 50 years ago with its first factory located in the north of Jakarta, covering an area of 4.6 hectares.

With the company’s production development over the years and the increase of the company’s team, the company has been committed to becoming the best steel supplier for various construction industries in Indonesia and surrounding areas.

The company has its own factory and warehouse, which can deliver the products required by customers in the shortest time, and can support small batch customization.

More Steel Companies:

Steel companies in the USA

Best steel company in India

Steel company in the Philippines

Steel company in UAE

Top 10 steel companies in Malaysia

Steel companies in South Africa

Steel companies in the UK

Steel companies in Canada

Summary

These are the world’s largest steel companies, please consult them for any steel product needs. Are you still looking for a steel coil manufacturer?

See here:

Steel Coil Manufacturers

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