Abstract
This specification covers steel sheet, in coils and cut lengths, metallic-coated by the hot-dip process, with zinc-aluminum alloy coating. The coating is produced as two types: zinc-aluminum-mischmetal alloy (Type I) and zinc-aluminum-magnesium alloy (Type II), and in two coating structures. Coated sheet is produced in several coating designations (coating weight [mass]). Material is classified in terms of the base metal and in terms of the coating. Base metal material classification is as follows: commercial steel (CS Types A, B, and C), forming steel (FS Types A and B), deep drawing steel (DDS), extra deep drawing steel (EDDS), structural steel (SS), high-strength low-alloy steel (HSLAS), and high-strength low-alloy steel with improved formability (HSLAS-F). Structural steel and high strength low alloy steel are available in several grades based on mechanical properties. Structural steel grade 50 [340] is available in three classes based on tensile strength. Heat analysis of the base metal for CS , FS, DDS, and EDDS shall conform to the chemical composition requirements in carbon, manganese, phosphorus, sulfur, aluminum, copper, nickel, chromium, molybdenum, vanadium, titanium, nitrogen, and boron and chemical composition in carbon, manganese, phosphorus, sulfur, copper, nickel, chromium, molybdenum, vanadium, titanium, nitrogen for SS, HSLAS, and HSLAS-F. Structural steel shall conform to the required yield strength, tensile strength, and elongation. Coating shall conform to the coating weight according to triple-spot test and single-spot test and shall be capable of bending without flaking.
Scope
1.1 This specification covers steel sheet, metallic-coated with zinc-5 % aluminum alloy via the hot dip process, in coils and cut lengths. The Zn-5Al alloy coating also contains small amounts of elements other than zinc and aluminum that are intended to improve processing and the characteristics of the coated product.
1.2 The coating is produced as two types: zinc-5 % aluminum-mischmetal alloy (Type I) and zinc-5 % aluminum-0.1 % magnesium alloy (Type II), and in two coating structures (classes). The coated sheet is produced in several coating designations (coating weight [mass]) as shown in Table 1.
1.3 The product is intended for applications requiring corrosion resistance, formability, and paintability.
1.4 The product is available in a number of designations, grades, and classes in four general categories that are designed to be compatible with different application requirements.
1.4.1 Steels with mandatory chemical requirements and typical mechanical properties.
1.4.2 Steels with mandatory chemical requirements and mandatory mechanical properties.
1.4.3 Steels with mandatory chemical requirements and mandatory mechanical properties that are achieved through solid-solution or bake hardening.
1.5 The product furnished under this specification shall conform to the applicable requirements of the latest issue of Specification A924/A924M, unless otherwise provided herein.
1.6 The text of this specification references notes and footnotes that provide explanatory material. These notes and footnotes, excluding tables and figures, shall not be considered as requirements of this specification.
1.7 Units—This specification is applicable to orders in either inch-pound units (as A875) or metric (SI) units [as A875M]. Values in inch-pound and SI units are not necessarily equivalent. Within the text, the SI units are shown in brackets. Each system shall be used independently of the other.
1.8 Unless the order specifies the “M” specification designation (SI units), the material shall be furnished to inch-pound units.
1.9 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.10 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
