scope:

This specification covers the requirements for continuous cast, cold rolled, retained austenite bearing sheet steel with specified minimum tensile strengths from 690 MPa to 1180 MPa.

Material Description

This specification applies to uncoated and coated retained austenite bearing advanced high strength steels that rely on one or more induced plasticity mechanisms to achieve enhanced combinations of strength and ductility relative to high strength steels. Common references to these steel types include transformation induced plasticity (TRIP) steel, TRIP-aided bainitic ferrite (TBF) or carbide-free bainite (CFB), quench and partition (Q&P) steel, and medium manganese TRIP steel. All products shall contain significant fractions of retained austenite and one or more of the following phases/microsconstituents: primary ferrite, bainite, bainitic ferrite, martensite, and tempered martensite. The presence of the following phases might also be expected: cementite, transition carbides, alloy carbides/nitrides/carbonitrides. The product phase/microconstituent composition, steel chemistry, and process path/annealing practice shall determine the common steel type designation according to accepted industry terminology and nomenclature. These products shall be supplied as coils or sheets. Cold rolled products with the appropriate surface type and surface finish are suitable for the application of surface coatings, metallic hot dipping, electrolytic plating, hot spray painting, organic coatings and/or other coatings. This specification does not apply to steel for case hardening and cold reduced, work hardened strips. 

Symbols.

Not applicable.

Applicability.

Typical applications include body panels, body structure members, and reinforcements for enhanced strength and vehicle impact performance.