G450 steel can be applied to Z, ZF, ZA, ZM, AZ, AM hot dip metallic coatings.

G450 Requirements for Chemical Composition

G450 Mechanical property requirements

G450 Coating Adhesion (180° bend test) requirements

G350 steel can be applied to a variety of hot dip coatings:

Zinc coating (Z).

Zinc coating converted to zinc/iron alloy (ZF).

Zinc/aluminium (ZA).

Zinc/aluminium/magnesium (ZM).

Aluminium/zinc (AZ)

Aluminium/zinc/magnesium (AM).

G350 Requirements for Chemical Composition

G350 Mechanical property requirements

G350 Coating Adhesion (180° bend test) requirements

G250 steel is a kind of low-carbon structural steel, which is used in metal roofs, walls, purlins, etc. It has good weldability.

G250 Requirements for Chemical Composition

G250 Mechanical property requirements

G250 Coating Adhesion (180° bend test) requirements

The common hot-dip metallic coated of G300 steel is ZINCALUME® and galvanized.

G300 Requirements for chemical composition

G300 Mechanical property requirements

G300 Coating Adhesion (180° bend test) requirements

Hot Rolled Coil Price Chart

HRC prices vary from country to country.

Chinese HRC prices:

URL https://finance.sina.com.cn/futures/quotes/HC0.shtml

The website is in Chinese, 3532 means that the price of hot-rolled coil per ton is 3532 yuan, and the currency is RMB.

U.S. HRC prices:

URL https://www.investing.com/commodities/us-steel-coil-futures-historical-data

The price of hot rolled coil in the United States is US$1,099 per ton.

Factors Influencing the Price of Hot Rolled Coil

1 supply and demand

The demand side includes engineering infrastructure, manufacturing and processing, etc. When the global demand for hot-rolled coils is strong, the price will increase. Hot-rolled coils are the raw material for galvanized roofing. For example, when earthquakes occur in some countries, metal roofing is required to build a large number of temporary houses.

The production capacity and operating rate of factories including hot-rolled coils on the supply side.

2 raw material cost

Iron ore, steel scrap, coal, and natural gas are raw materials for producing hot-rolled coils, and their price changes will affect the price of hot-rolled coils

4 stock

Including changes in global social inventory and steel mill inventory data

5 Macro policies

The Chinese government’s steel mills implement environmental protection policies to limit production capacity, and the US government imposed a 25% tariff on hot-rolled coils in 2018, which will affect prices.

What is Zincalume Steel?

Zincalume steel is a type of steel that has a coating made of a combination of aluminum, zinc, and silicon. This coating is applied to the steel in a continuous hot-dip process, which results in a highly corrosion-resistant and durable material.

Zincalume steel coil is commonly used in construction for roofing, walling, and fencing applications. It is highly valued for its superior corrosion resistance as well as its ability to withstand extreme weather conditions.

Additionally, zinc-plated steel is lightweight, easy to handle and install, and has a long lifespan. Overall, zinc is a popular and versatile material that is used in a wide range of industries for its strength, durability, and resistance to corrosion.

The development of Zincalume began in 1976 to serve the building needs of customers in Australia. After 20 years, it has leveled up by introducing Zincalume® steel with Activate® technology.

It underwent several tests at BlueScope’s production facilities in New South Wales, Australia. The technology adheres to the AS/NZS 1365:1996 (R2016) and AS 1397:2021 Australian Standards. The BlueScope warranties ensure that the steel can last for years with less maintenance.

AM vs. AZ

Zincalume® aluminum/zinc/magnesium alloy coated steel, also known as AM, uses patented Activate® technology.

AM offers good performance due to the changes in composition as well as its coating structure to withstand harsh environments. It is composed of 55 percent aluminum, 2 percent magnesium, 1.5 percent silicon, and a balance of zinc.

AM is more resilient and long-lasting compared to Zincalume® aluminum/zinc alloy coated steel (AZ). AZ was developed by BlueScope in 1976 by coating the steel with 55 percent aluminum, 1.5 percent silicon, and a balance of zinc.

Source: https://cdn.dcs.bluescope.com.au/download/ctb-06

Coating Structure

To give you a clear picture of the coating structure of Zincalume steel, take a look at the two figures below. Figure 1a shows the AZ coating microstructure consisting of dendrites and interdendritic regions. It is in the interdendritic region where the zinc coating lies, while the aluminum coating lies in the dendrites.

The silicon, which resembles needle particles, lies in the interdendritic region. A formation of Zn, Al, Si, and Fe at the interface of the steel acts as a bond between the coating and the base steel.

An image showing the cross-section of the typical microstructures of AM and AZ coatings

Fig. 1A: An image showing ZINCALUME® steel AZ150 (superseded)

Fig. 1b: An image showing the next generation ZINCALUME® steel AM125

Take a look at figure 1b. You will see the AM alloy coating microstructure consisting of a zinc-rich matrix where the aluminum lies. You will find fine particles of magnesium silicide (Mg2Si) and magnesium zinc (MgZn2).

Most of the magnesium silicide is going towards the coating layer’s bottom part. The magnesium-zinc goes in the direction of the coating layer’s top part. Both positions of the MgZn2 and Mg2Si reinforce the AM coating’s resistance to corrosion.

https://cdn.dcs.bluescope.com.au/download/ctb-06

Corrosion Protection Mechanisms

The coating of aluminum/zinc alloy-coated steel guards the steel against corrosion. (figure1c)

Figure 1d shows the protective mechanism of the aluminum/zinc/magnesium alloy-coated steel. The metallic coating guards the steel against corrosion. The MgZn2 that lies on top of the coating offers sacrificial protection at the start of the weathering of the steel.

Figure 1e shows how the aluminum-rich dendrites act as a barrier against corrosion while the zinc area starts corroding. Over the years of use, the aluminum-rich areas slowly corrode when the zinc-rich region becomes exhausted, giving a limited sacrificial protection to the steel base.

When the weathering of the coating is at its peak, Mg2Si begins to activate the aluminum-rich areas. The sacrificial protection on the steel base is not limited compared to the MgZn2. It prevents the development of red rust even in harsh environmental conditions over the years. See Figure 1f.

Source: https://cdn.dcs.bluescope.com.au/download/ctb-06

Cut Edges

The zinc-rich interdendritic region where there is atmospheric exposure results in corrosion at the cut edges and scratches. It is in these areas where the corrosion acts as a sacrificial protection, blocking off extreme corrosion after filling up the coating’s cavities.

AM offers resilient and long-lasting anti-corrosion properties at cut edges and scratches. The magnesium silicide particles provide extraordinary protective barriers to slow down corrosion. It blocks the corrosion gateways to the substrate.

Source: https://cdn.dcs.bluescope.com.au/download/tb-10

Bends

Both Colorbond® and Zincalume® steels are manufactured as flat sheets before passing through pressing or roll forming.

The paint and coating in Colorbond steel stretch the paint and coating, which leads to cracking. AM coatings are less ductile as they are harder compared to AZ coatings. It leads to cracking in the steel’s tight bends.

Image showing the 90-degree bend of unpainted steel exposed in marine area.

https://cdn.dcs.bluescope.com.au/download/tb-10

Conclusion

AM coatings are more resilient and long-lasting than AZ coatings. But it all depends on the application of the steel. Zincalume’s Al-Zn-Mg coatings offer barrier protection to the steel base even after several years of use.

G550 steel can provide the following hot-dip coatings:

Zinc coating (Z).

Zinc coating converted to zinc/iron alloy (ZF).

Zinc/aluminium (ZA).

Zinc/aluminium/magnesium (ZM).

Aluminium/zinc (AZ)

Aluminium/zinc/magnesium (AM).

G550 Requirements for Chemical Composition

G550 Mechanical Property Requirements

G550 Coating Adhesion (180° bend test) requirements

G550 Steel equivalent

Use of G550 Steel

Roofing,
Cladding,
Roll-formed sections for structural applications

What is ZAM steel?

ZAM steel is a brand of steel made by Nippon Steel Corporation. This hot-dip coated steel sheet boasts of its ability to fight corrosion over many years of use. The coating layer consists of 6 percent aluminum, 3 percent magnesium, and the rest is zinc. ZAM is an acronym for zinc, aluminum, and magnesium.

ZAM steel has a wide market due to its unique composition and long-lasting performance compared to hot-dip galvanized coatings. The technological advancement of ZAM makes it a sought-after brand worldwide that complies with the AS1397:2011 standards.

The blend of aluminum and magnesium makes the steel resistant to corrosion and scratches. The aluminum content is the secret to its high formability, which makes ZAM versatile in various applications.

ZAM’s superior anti-corrosion properties make it an excellent material for structures that are exposed to harsh environments. Its applications include boat and marina sheds, horticultural and agricultural sheds, refineries, spa and pool areas, and outdoor composite slabs.

Corrosion resistance mechanism of ZAM steel

ZAM’s corrosion resistance mechanism is due to its coating layer of aluminum and magnesium. The blend of Mg and Al creates an enduring protective film on its zinc base, giving protection against corrosion.

Compared to hot-dip galvanized coating layers, ZAM offers a finer and tighter adhesive property on the substrate. ZAM’s coating surfaces block the corrosive action over a long period of exposure to harsh environments.

In a salt spray test that lasted for four hours on both ZAM and hot-dip galvanized steel, ZAM formed a protective film on the coating surface. Take a glimpse at the figure below:

The cut-edge parts of the ZAM steel have superior corrosion resistance. The ends are covered with a fine base that contains a protective film comprising aluminum and magnesium leaching on its coating layer.

The corrosion resistance on the cut edge was based on a test on the steel substrate. The initial exposure period took several weeks, during which there was an initial rust on the exposed cut edge. The rust formed due to oxidation from condensation and rain.

The intermediate exposure period took several weeks to years. During this period, the cut edge resists corrosion due to the fine zinc-based protective film, which has a leaching of zinc, aluminum, and magnesium coating layers. The substrate turns darker to gray-black over the years of exposure to the elements.

Weldability

The coating layer of ZAM steel affects its weldability performance due to its zinc base. Zinc has a low melting point, which is not ideal for arc welding. This application leads to weak joints and deformation compared to cold- and hot-rolled steel sheets.

ZAM is prone to splashing, hole formation, and cracking. ZAM performs better if you weld it into joints, provided the structure has adequate strength and is under proper conditions.

Experts recommend conducting tests when welding ZAM steel to achieve greater strength and maximum welding parameters. The weld quality depends on the type of welding machine and shape of the joints.

Defective joints are avoidable if you follow the right conditions when welding ZAM steel. The joints should have enough weld strength and adequate internal sectional structure before welding the steel.

Applications

ZAM is a versatile steel brand that is useful in various applications. ZAM is popular choice in the building and construction sector. It is used for making refrigerant ducts, ceiling crosspieces, indoor baseball fields, sound barrier louvers, heavy-duty shutters, and house frames.

In road and civil engineering, its uses include bridge reinforcing plate, soundproof wall (ZPG treatment), wind barrier panel, sound barrier, sound barrier member, snow fence, guardrail, bridge railing, pipe for joining bolts of concrete block, rock bolt, windbreak screen, drain reinforcement pipe, handrail in tunnel, steel pipe pile, and fireproof protection for optical fiber.

ZAM is ideal for making automobile parts such as wiper linkage, filter case, radiator fan motor cover, starter motor yoke, hood lock, horn, pulley, splash guard, window regulator motor yoke, tank heat protector, constant velocity joint cover, and lower sash.

ZAM steel is also used in making electric power and electric equipment, farming structures, railroads, housing, and construction.

Conclusion

ZAM steel is a high-performing brand that can withstand corrosion even after many years of use. The color may fade, but its resistance to corrosion is unmatched compared to galvanized sheets.

References:

https://www.nipponsteel.com/product/catalog_download/pdf/U110en.pdf

ZAM Case Study. Nipponsteel

What is aluminum zinc alloy coated steel?

Aluminum-zinc alloy-coated steel is also known as galvalume. It is a type of metallic-coated steel product with a layer of aluminum, zinc, and silicon coated onto a steel sheet or coil. This coating provides both corrosion resistance and heat reflectivity to the steel, making it suitable for a wide range of applications.

The process of making galvalume involves coating the steel sheet with a layer of molten aluminum-zinc alloy. The aluminum provides a barrier to corrosion. The zinc provides extra layer of protection for the steel. The silicon is added to the alloy to improve the adhesion of the coating to the steel substrate.

Galvalume is often used in construction applications, such as roofing and siding. Automotive and appliance industries use it in making parts and components. It is known for its durability, resistance to corrosion, and low maintenance requirements.

The zinc, aluminum, and silicon coatings provide protection for the base metal, which is similar to galvanization.

Aluminum Zinc Alloy vs. Galvanized Coatings

Galvanized coatings are made by applying a layer of zinc to a steel substrate. This can be done through either hot-dip galvanizing or electroplating. The zinc provides sacrificial protection to the steel, meaning that it will corrode before the steel does.

Galvanized coatings are often used in applications where the steel will be exposed to corrosive environments, such as outdoor structures or equipment.

Aluminum, zinc, and silicon comprise the steel substrate of aluminum-zinc alloy coatings. The aluminum provides a barrier to corrosion, while the zinc provides sacrificial protection.

The silicon is added to improve the adhesion of the coating to the steel substrate. Aluminum-zinc alloy coatings are known for their superior corrosion resistance compared to galvanized coatings, especially in harsh environments.

Galvanized coatings have a characteristic bright and shiny finish. Aluminum-zinc alloy coatings have a duller, matte appearance.

Aluminum Zinc Alloy Coated Steel Life

Aluminum-zinc alloy-coated steel can last for several decades of use. A comparative study of roofing was conducted in Northern America, which is subject to industrial and acid rains.

There was a deterioration in galvanized roofing compared to 55 percent aluminum-zinc sheets. The 55% Al-Zn sheet looks like new, even if the surface has lost its sheen due to dirt and exposure to the elements.

Since 1994, there has been little change in the aluminum-zinc coatings over galvanized sheets. Experts concluded that the life expectancy of 55 percent aluminum-zinc coated steel is twice that of steel that undergoes the hot dip galvanization process.

The long-term evaluations in Indianapolis in 1994 proved that steel sheets with 55 percent Al-Zn can last for thirty to forty years. For marine applications, the lifespan could be twice that of galvanized sheets.

The durability of Al-Zn coatings can save money on repairs and maintenance of the roofing sheet even if the surface cosmetic value has diminished over the years.

https://www.steelroofing.com/assets/doc/40yearsoflife.pdf

Conclusion

There is no doubt that the 55% aluminum-zinc alloy coated steel performs better than galvanized sheets. The test results showed its versatility and long-lasting performance, which is cost-saving

What is Pre-Painted Steel Coil?

Pre-painted steel coil, also known as pre-coated steel coil or color-coated steel coil, is a product made of hot-dip galvanized steel sheet, hot-dip galvalume steel sheet, electro-galvanized steel sheet, etc. that has been coated with one or more layers of organic paint or other protective coatings.

The pre-painting process protects the metal substrate from corrosion. It improves its durability and aesthetic appearance and provides a wide range of color choices.

According to the EN-10169-1 standard, an organic coating material is applied to the rolled metal strip to protect it from corrosion. Cleaning and pre-treatment of chemicals are applied to one or both sides of the metal surface with a single or multiple coats of paint or powder.

Pre-painted steel coils are widely used in various applications, such as:

• indoor and outdoor applications in building and construction (roofing, wall cladding, garage doors)
• domestic appliances (refrigerators, washing machines, bakeware)
• cabinets and office furniture
• transport and automotive sectors
• lighting fittings

Pre-painted steel coils come in a variety of color coatings, surface textures, and gloss levels. The paint coatings have high chemical resistance, flexibility, and non-stick properties.

The coated coils are available in different cuts. Customers may request coils with narrow widths, profiled, deep drawn, and different lengths and shapes. There are a variety of pre-painted steel coils as manufacturers continue to develop modern designs and coatings.

Substrate of Pre-Painted Steel Coil

The substrate of a pre-painted steel coil refers to the base metal, where the organic coating takes place. The substrate of pre-painted steel coil include the following:

Hot Dipping Galvanized Steel Coil

Hot-dip galvanized steel coil is a substrate made by immersing steel in a bath of molten zinc to create a layer of zinc coating that protects the steel from corrosion. This method adopts galvanizing production as a continuous process. The cold-rolled coils stay in the dissolved zinc bath to continue their galvanizing process.

Hot Dipping Galvalume Steel Coil (55% aluminum/zinc)

Hot-dip galvalume steel is a popular choice for cladding and construction uses. This substrate offers corrosion resistance to the steel when exposed to harsh environments. The zinc coating provides galvanic protection when the steel surface suffers from scratches over many years of use, keeping the steel functional and intact.

Zinc-magnesium-coated steel

Zinc-magnesium-coated steel replaces steel and has a coating of 1 to 3.5 percent magnesium and 0.5 to 3.5 percent aluminum. It achieves metastable eutectic structure by fast cooling after a molten zinc bath.

The steel has a better performance against corrosion compared to hot-dipped galvanized steel, which has a pure zinc coating. Zinc, magnesium, and aluminum form an oxide protection layer on the steel, which means it can stand against corrosion at the exposed edges and boundary layer.

Product Life of Pre-Painted Steel Coil

Pre-painted steel coils can last for several years because the paint offers an extra layer of protection to the steel. Paints contain corrosion-inhibiting agents that can thwart moisture, heat, oxygen, and corrosion-inducing agents from causing damage to the steel.

Although paints fade over time and become dull due to heat, they can minimize the damage to the steel even if moisture penetrates the paint. Paint manufacturers have developed paint coatings with advanced features by adding corrosion-inhibiting agents.

These inhibiting agents lie at the interface between the metal and the paint coating. They minimize rusting and corrosion to the steel. The inhibiting agents protect the metal from losing its adhesion to the paint when there are blisters and scratches at the exposed areas.

The agents also protect the paint from undercutting corrosion, so the metal does corrode even if there are scratches and cut edges. Paints help improve the product life of steel sheets and coils depending on several factors.

These factors include the paint coating thickness, resistance to harsh environmental conditions, primer coating, and paint pre-treatment that contains corrosion-inhibiting agents.

Choose a paint that has a lower moisture permeability. This type of paint protects the steel from flaking and blistering due to water absorption. Optimizing the product life of pre-painted steel coils depends on the choice of paint and treatment technology.

Choose a paint that contains corrosion-inhibiting agents. Ensure that you apply the right primer coating, metallic coating type, and pre-treatment to make the steel last for years.

Source:

https://www.galvinfo.com/wp-content/uploads/sites/8/2017/05/GalvInfoNote-4-1.pdf

Paint System Durability

Although pre-painted steel coil greatly extends the service life of the product, when the life reaches the limit. They may fail in some aspects, like fading and chalking, that affect the aesthetic value of the product.

Paints are prone to blistering and flaking over time. It occurs when the paint separates along the pretreatment or metallic coating bond line, the primer or pre-treatment bond line, and the primer/paint bond line.

There are factors that influence the durability of the paint system. Such factors are in relation to the combination of the pre-treatment, primer, and paint coating to the elements and environmental conditions. Paints may lose their adhesion if there is corrosion of the steel substrate.

Latitudinally undercutting corrosion is the most common form of paint failure. It is due to a scratch at the exposed edge or in the paint. Chemical reactions, moisture, and heat exposure can also cause bulk corrosion and degradation of the adhesion bond, which leads to paint damage.

Advantages of Pre-Painted Steel Coil

Prepainted steel coils have an organic coating layer that offers resistance to corrosion and guarantees longevity. Here are the advantages of pre-painted steel:

Advantages in Design

Prepainted steel products are aesthetically appealing due to their design, texture, and color variations. The surface finish comes in printed films that look like woodgrain, matte, high gloss, embossed, orange-peel, or smooth. They are available in various aluminum alloys and grades that are easy to bend and adjust during application.

Manufacturers are producing sustainable and recyclable prepainted steel. This steel has a superior performance against corrosion despite its thinner organic coatings, which are common in post-applied films and powder. The organic coatings are less costly as they do not need regular repainting and maintenance.

Sustainable in Life Span

Prepainted metals undergo a coil coating process that offers long-lasting service without costing much. Since they are organic paint coatings, they are less costly but offer a sustainable, effective, and reliable design solution for various applications.

Manufacturers take close supervision during the coating operations, ensuring that the prepainted metals yield a premium, recyclable, and sustainable design that can last for up to forty years in the harshest environments.

Coil Coated Metal Joining and Forming

Prepainted metals have a high formability, which means they are easy to bend, blank, form, draw, and rewind. Driving mechanical fasteners like rivets, screws, bolts, and Tog-L locks does not require extra force. They are easy to bind using an adhesive bond or lock seam.

They are weldable and formable into different shapes due to their aluminum content. The surface is free of dirt and imperfections as the aluminum and steel undergo cleaning, priming, painting, and curing. They offer superior performance to their post-painted counterparts.

Prepainted Metal and Cut-Edge

Prepainted steel coils boast of their prepainted cut-edge that offers superior performance for several years. The reason is that cut edges are less susceptible to corrosion compared to post-painted metals without exposed edges.

Source:

https://prepaintedmetal.eu/874/889

https://prepaintedmetal.eu/875/benefits

https://www.coilcoating.org/media-resources/prepainted-metal-can-provide-cost-and-quality-benefits-to-manufacturers

Types of Top Coating

Pre-painted steel coils offer a long-lasting solution to building and construction needs. They boast of an organic coating layer that guarantees high resistance to corrosion, making them last for years compared to galvanized steel sheets. Their base metals consist of HDG electrogalvanized, hot-dip zinc-aluminum-magnesium, and cold-rolled.

Here are the top coatings on prepainted steel sheets and coils:

Polyester (PE)

Polyester coatings offer solidarity and flexibility to the metal sheets due to the monomer reactants used during the formulation of the polyester resin. These reactants have the ability to regulate the polyester’s performance during application. They consist of physical properties that enable them to resist weathering and degradation to the metal over many years of use.

High Durable Polyester (HDP)

High-durability polyester resin refers to a coating consisting of a high-molecular-weight polyester resin with a lesser amount of branched polymer. The polyester resin can be hydroxyl or carboxyl functional, which offers superior resistance to ultra violet compared to an ordinary polyester resin. These high-molecular-weight resins contain a high amount of isophthalic acid and can withstand aggressive environments.

Silicone Modified Polyester (SMP)

SMP is an improved version of commercial coil coatings due to its solvent-based chemistry. Comparing with PVDF coatings, SMP’s polyester can stand against weathering, while its silicon content offers gloss coating retention. The downside of SMP is that it is less flexible because the polymers have a branched structure and high crosslinks.

Polyvinylidene Fluoride (PVDF)

PVDF is a solvent-based architectural paint system that has superior weathering properties compared to other coating types. Its vinylidene fluoride monomer undergoes homopolymerization. This method allows the production of materials with an unobtrusive molecular weight and size suitable for a specific application.

The melamine-acrylic composition of PVDF is 70 percent PVDF and 30 percent acrylic for superior weathering performance and properties. Its downside is that it is costly and less flexible.

Source: https://www.galvinfo.com/wp-content/uploads/sites/8/2017/05/GalvInfoNote-4-1.pdf

Process of Pre-Painted Steel Coil

The fabrication of prepainted steel coils and sheets begins with the delivery of the substrate in coil form directly from the rolling mills. There are three sections involved in the coil coating line: entry, processing, and exit.

Each step ensures that the finished prepainted metal products are durable, high-performing, and aesthetically appealing. The machines in the production line work simultaneously to paint 2,000 to 4,000 square feet of metal strips per 4 minutes.

Here are steps at the coating line:

Step 1: Cleaning the Metal Strip

Cleaning up the oil, dirt, and impurities of the cold-rolled coil involves brushing, an alkaline dip, a water bath, or brushing.

Step 2: Application of Zinc and Alloy

The application of aluminum and zinc depends on the application and customer requirements. Some products consist of 100 percent zinc, while others contain magnesium alloy.

Step 3: Treatment of the Surface

This step is vital to ensuring that the paint and primer bond well with the metal strip. Due to some chemical restrictions, the surface is treated with chemicals, such as alkaline oxidation, depending on the supplier and country of origin.

Step 4: Metal Rinsing and Drying

Rinsing the metal strip helps ensure that it has no chemical residue before applying primer. Drying the metal is a must to ensure that the subsequent layers bond well.

Step 5: Application of Primer

A coating of primer can be on one or both sides of the metal strip. Primer application hastens the adhesion of the finished paint layer.

Step 6: Curing and Cooling the Strip

Curing takes 15 to 16 seconds. This method allows the primer to harden, dry, and reach the desired temperature before applying the next coating.

Step 7: Front and Back Coating

This step is the final painting stage, wherein two-coat paint systems are applied.

Step 8: Drying, Curing, and Cooling

The product undergoes this step to ensure that the steel product is ready for rewinding, rerolling, and shipping to end users.

Step 9: Packaging

Image showing a coil coating line schematic.

Source: https://www.coilcoating.org/process

Conclusion

The choice of steel substrate depends on the specific requirements of the application. Users must consider the level of corrosion resistance, aesthetics, and cost when choosing a steel product.