【国外标准】 Standard Specification for Normalized High-Strength Low-Alloy Structural Steel Plates

This specification covers normalized high-strength low-alloy structural steel plates for welded, riveted, or bolted construction. This material is suited for low ambient temperatures where the desired notch toughness is better than that expected in as-rolled materials of comparable strength level. The material shall have fine austenitic grain size and shall be normalized by heat treatment. Its chemical composition shall be determined by heat analysis. Tension tests shall also be done.1.1 This specification covers normalized high-strength low-alloy structural steel plates for welded, riveted, or bolted construction.1.2 This material is particularly suited for service at low ambient temperatures of −50°F [−45°C] and higher where notch toughness better than that expected in as-rolled material of a comparable strength level is desired.1.3 Four grades, designated Grades A, C, D, and E are covered by this specification. Grade A provides a minimum yield point of 42 ksi [290 MPa]. Grades C and D provide a minimum yield point of 50 ksi [345 MPa] in thicknesses up to 2.50 in. [65 mm], inclusive and 46 ksi [315 MPa] in thicknesses over 2.50 in. [65 mm]. Grade E provides a minimum yield point of 60 ksi [415 MPa] in thicknesses up to 4.0 in. [100 mm], inclusive and 55 ksi [380 MPa] in thicknesses over 4 in. [100 mm].1.4 Current practice normally limits plates furnished under this specification to maximum thickness of 4 in. [100 mm] for Grades A, C, and D, and to a maximum thickness of 6 in. [150 mm] for Grade E. However, the maximum thickness of the plates is limited only by the capacity of the composition to meet the specified mechanical property requirements.1.5 When the steel is to be welded, it is presupposed that a welding procedure suitable for the grade of steel and intended use or service will be utilized. See Appendix X3 of Specification A6/A6M for information on weldability.1.6 The values stated in either inch-pound units or SI units are to be regarded as standard. Within the text, the SI units are shown in brackets. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.1.7 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.