Standard Specification for Steel Sheet, 55 % Aluminum-Zinc Alloy-Coated by the Hot-Dip Process
A792 Free Download
Definition
This specification covers 55 % aluminum-zinc alloy coated steel sheet in coils and cut lengths.
This product is intended for applications requiring corrosion resistance or heat resistance, or both.
The product is produced in a number of designations, types, and grades which are designed to be compatible with differing application requirements.
Product furnished under this specification shall conform to the applicable requirements of the latest issue of Specification A924/A924M, unless otherwise provided herein.
The text of this specification references notes and footnotes that provide explanatory material. These notes and footnotes, excluding those in tables and figures, shall not be considered as requirements of this specification.
This specification is applicable to orders in either inch-pound units (as A792) or SI units (as A792M). Values in inch-pound and SI units are not necessarily equivalent. Within the text, SI units are shown in brackets. Each system shall be used independent of the other.
Unless the order specifies the “M” designation (SI units), the product shall be furnished to inch-pound units.
This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use
Information
TABLE 1 Weight [Mass] of Coating Requirements
| Minimum Requirements | ||
|---|---|---|
| Triple-Spot Test | Single-Spot Test | |
| Inch-Pound Units | ||
| Coating Designation | Total Both Sides, oz/ft2 | Total Both Sides, oz/ft2 |
| AZ30 | 0.3 | 0.26 |
| AZ35 | 0.35 | 0.3 |
| AZ40 | 0.4 | 0.35 |
| AZ50 | 0.5 | 0.45 |
| AZ55 | 0.55 | 0.5 |
| AZ60 | 0.6 | 0.52 |
| AZ70 | 0.7 | 0.6 |
| Minimum Requirements | ||
| Triple-Spot Test | Single-Spot Test | |
| Inch-Pound Units | ||
| Coating Designation | Total Both Sides, g/m2 | Total Both Sides, g/m2 |
| AZM100 | 100 | 25 |
| AZM110 | 110 | 95 |
| AZM120 | 120 | 105 |
| AZM150 | 150 | 130 |
| AZM165 | 165 | 150 |
| AZM180 | 180 | 155 |
| AZM210 | 210 | 180 |
Chemical Composition
Base Metal:
The heat analysis of the base metal shall conform to the requirements of Table 2 for CS (Types A, B, and C), FS, DS, HTS, Table 3 for SS.
Include each of the elements listed in Tables 2 and 3 in the report of heat analysis. When the amount of copper, nickel, chromium, or molybdenum is less than 0.02 %, report the analysis either as <0.02 %o or the actual determined value. When the amount of vanadium, titanium, or columbium is less than 0.008 %o. report the analysis either as <0. 008 %o or the actual determined value. When the amount of boron is less than 0.0005 %o, report as <0.0005 %o or the actual determined value.
Coating Composition—The 55 % aluminum-zinc alloy coating composition, by weight, is nominally 55 % aluminum, 1.6 % silicon, and the balance zinc.
Mechanical Properties
Structural Steel sheet shall conform to the mechanical property requirements of Table 4 for the grade specified.
The typical mechanical properties for CS (Types A, B, and C), FS, DS, and HTS are listed in Table 5. These typical mechanical properties are nonmandatory. They are intended solely to provide the purchaser with as much information as possible to make an informed decision on the steel to be specified. Values outside these ranges are to be expected.
A792/A792M - 10
| TABLE 2 Chemical RequirementsA | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Composition, %—Heat Analysis Element, Maximum, Unless Otherwise Shown | ||||||||||||||
| Designation | C | Mn | P | S | Al | Cu | Ni | Cr | Mo | V | Cb | TiB | N | B |
| CS Type A C, D, E | 0.1 | 0.6 | 0.03 | 0.035 | ... | 0.25 | 0.2 | 0.15 | 0.06 | 0.008 | 0.008 | 0.025 | ... | ... |
| CS Type B C, F | 0.02 to 0.15 | 0.6 | 0.03 | 0.035 | ... | 0.25 | 0.2 | 0.15 | 0.06 | 0.008 | 0.008 | 0.025 | ... | ... |
| CS Type C C, D, E | 0.08 | 0.6 | 0.1 | 0.035 | ... | 0.25 | 0.2 | 0.15 | 0.06 | 0.008 | 0.008 | 0.025 | ... | ... |
| FSC , G | 0.02 to 0.10 | 0.5 | 0.02 | 0.03 | ... | 0.25 | 0.2 | 0.15 | 0.06 | 0.008 | 0.008 | 0.025 | ... | ... |
| DSD , E | 0.06 | 0.5 | 0.02 | 0.025 | 0.01, min | 0.25 | 0.2 | 0.15 | 0.06 | 0.008 | 0.008 | 0.025 | ... | ... |
| HTSC | 0.02 to 0.15 | 0.6 | 0.040, min | 0.035 | ... | 0.25 | 0.2 | 0.15 | 0.06 | 0.008 | 0.008 | 0.025 | ... | ... |
| TABLE 3 Chemical Requirements | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Composition, %—Heat Analysis Element, maximum, Unless Otherwise Shown | ||||||||||||
| Designation | C | Mn | P | S | Cu | Ni | Cr | Mo | V | Cb | TiA | NB |
| Structural Steel: | ||||||||||||
| Grade 33 [230] | 0.2 | 1.35 | 0.04 | 0.04 | 0.25 | 0.2 | 0.15 | 0.06 | 0.008 | 0.008 | 0.025 | ... |
| Grade 37 [255] | 0.2 | 1.35 | 0.1 | 0.04 | 0.25 | 0.2 | 0.15 | 0.06 | 0.008 | 0.008 | 0.025 | ... |
| Grade 40 [275] | 0.25 | 1.35 | 0.1 | 0.04 | 0.25 | 0.2 | 0.15 | 0.06 | 0.008 | 0.008 | 0.025 | ... |
| Grade 50 Class 1, Class 2, and Class 4 [340 Class 1, Class 2, and Class 4] | 0.25 | 0.25 | 0.2 | 0.04 | 0.25 | 0.2 | 0.15 | 0.06 | 0.008 | 0.008 | 0.025 | ... |
| Grade 60 [410] | 0.25 | 1.35 | 0.2 | 0.04 | 0.25 | 0.2 | 0.15 | 0.06 | 0.008 | 0.008 | 0.025 | ... |
| Grade 70 [480] | 0.25 | 1.35 | 0.2 | 0.04 | 0.25 | 0.2 | 0.15 | 0.06 | 0.008 | 0.008 | 0.025 | ... |
| Grade 80 [550] Class 1 | 0.2 | 1.35 | 0.04 | 0.04 | 0.25 | 0.2 | 0.15 | 0.06 | 0.008 | 0.015 | 0.025 | ... |
| Grade 80 [550] Class 2 | 0.1 | 1.35 | 0.05 | 0.02 | 0.25 | 0.2 | 0.15 | 0.06 | 0.1 | 0.1 | 0.15 | ... |
| Grade 80 [550] Class 3 | 0.2 | 1.35 | 0.04 | 0.04 | 0.25 | 0.2 | 0.15 | 0.06 | 0.008 | 0.008 | 0.025 | ... |
All tests for mechanical properties shall be conducted in accordance with the methods described in Specification A924/ A924M. 7.4 Bending Properties:
Minimum Inside Radii for Cold Bending—Structural Steel sheet is commonly fabricated by cold bending. There are many interrelated factors that affect the ability of a steel to cold form over a given radius under shop conditions. These factors include thickness, strength level, degree of restraint, relationship to rolling direction, chemistry, and base metal microstructure. Table X2.1 lists the suggested minimum inside radii for 90° cold bending for Structural Steels. They presuppose “hard way” bending (bend axis parallel to the rolling direction) and reasonably good shop forming practices. Where possible, the use of larger radii or “easy way” bends are recommended for improved performance.
Fabricators should be aware that cracks may initiate upon bending a sheared or cold-worked edge. This is not considered to be a fault of the steel but is rather a function of the induced localized cold-work zone.
Coating Properties
Coating Weight [Mass]—
Coating weight [mass] shall conform to the requirements as shown in Table 1 for the specific coating designation.
Use the following relationships to estimate the coating thickness from the coating weight [mass]:
1.00 oz /ft2 coating weight = 3.20 mils coating thickness, and
3.75 g/m2 coating mass = 1.00 µm coating thickness
Use the following relationship to convert coating weight to coating mass:
1.00 oz/ft2 coating weight = 305 g/m2 coating mass
Coating Weight [Mass] Tests:
Coating weight [mass] tests shall be performed in accordance with the requirements stated in Specification A924/ A924M.
The referee method to be used shall be the dilute hydrochloric acid method, in Test Method A90/A90M.
Coating Bend Test—The coating bend test specimens for all designations other than Structural Steel shall be capable of being bent through 180° flat on itself in any direction without flaking on the outside of the bend only. For Structural Steel, the coating bend test inside diameter shall have a relation to the thickness of the specimen as shown in Table 6. Flaking of the coating within 0.25 in. [6 mm] of the edge of the bend specimen shall not be cause for rejection.
| TABLE 4 Mechanical Property Requirements, Structural Steel Base Metal (Longitudinal) | |||
|---|---|---|---|
| Inch-Pound Units | |||
| Grade | Yield Strength, min, ksi | Tensile Strength,A min, ksi | Elongation in 2 in., min, % |
| 33 | 33 | 45 | 20 |
| 37 | 37 | 52 | 18 |
| 40 | 40 | 55 | 16 |
| 50 Class 1 | 50 | 65 | 12 |
| 50 Class 2 | 50 | 12 | |
| 50 Class 3 | 50 | 60 | 12 |
| 60 | 60 | 70 | 10 |
| 70 | 70 | 80 | 9 |
| 80 Class 1 | 80 | 82 | |
| 80 Class 2 | 80 | 82 | |
| 80 Class 3 | 80 | 82 | 3 |
| SI Units | |||
| Grade | Yield Strength, min, MPa | Tensile Strength, min, MPa | Elongation in 50 mm, min, % |
| 230 | 230 | 310 | 20 |
| 255 | 255 | 360 | 18 |
| 275 | 275 | 380 | 16 |
| 340 Class 1 | 340 | 450 | 12 |
| 340 Class 2 | 340 | 12 | |
| 340 Class 3 | 340 | 410 | 12 |
| 410 | 410 | 480 | 10 |
| 480 | 480 | 550 | 9 |
| 550 Class 1 | 550 | 570 | |
| 550 Class 2 | 550 | 570 | |
| 550 Class 3 | 550 | 570 | 3 |
Retests and Disposition of Non-Conforming Material
Retests, conducted in accordance with the requirements of the section on Retests and Disposition of Non-Conforming Material of Specification A924/A924M, are permitted when an unsatisfactory test result is suspected to be the consequence of the test method procedure.
Disposition of non-conforming material shall be subject to the requirements of 9.2 of Specification A924/A924M. 10. Dimensions and Permissible Variations 10.1 All dimensions and permissible variations shall comply with the requirements of Specification A924/A924M.
| TABLE 5 Typical Ranges of Mechanical Properties | |||||
|---|---|---|---|---|---|
| (Nonmandatory)A, B | |||||
| Longitudinal Direction | |||||
| Designation | Yield Strength | Elongation 2 in. [50 mm] % | rm ValueC | n ValueD |
|
| ksi | MPa | ||||
| CS Type A | 30/60 | [205/410] | =20 | E | E |
| CS Type B | 35/60 | [245/410] | =20 | E | E |
| CS Type C | 30/60 | [205/450] | =15 | E | E |
| FS | 25/40 | [170/275] | =24 | 1.0/1.4 | 0.16/0.20 |
| DS | 20/35 | [140/240] | =30 | 1.3/1.7 | 0.18/0.22 |
| HTS | 30/65 | [205/450] | =15 | E | E |
| TABLE 6 Coating Bend Test Requirements—Structural Steel | |
|---|---|
| Grade | Ratio of the Inside Bend Diameter to Thickness of the Specimen (Any Direction) |
| 33 [230] | 1 1/2 |
| 37 [255] | 2 |
| 40 [275] | 2 1/2 |
| 50 Class 1, Class 2, and Class 4 | A |
| 60 | A |
| 70 | A |
| [340 Class 1, Class 2, and Class 4] 80 Class 1, Class 2, and Class 3 A [550 Class 1, Class 2, and Class 3] | A |
Dimensions and Permissible Variations
All dimensions and permissible variations shall comply with the requirements of Specification A924/A924M.
