High Strength Sheet Steel, 180 MPa through 550 MPa Yield Strengths
|Publication Date:||1 August 2007|
This specification covers the requirements for continuous cast sheet steel with specified minimum yield strengths from 180 MPa through 700 MPa and is applicable to uncoated and coated, cold or hot rolled low carbon, solid solution strengthened, bake-hardenable, interstitial free or high strength low alloy substrates with good formability. Continuously hot or cold rolled flat products shall be supplied as coils or sheet. Hot rolled flat products are usually supplied in thicknesses greater than 1.75 mm. These flat products are used for cold forming and for manufacturing of welded tubes. Cold rolled flat 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. Additional requirements or agreements shall be specified by regional GM Automotive Operations (GM) business units [e.g., North America (GMNA), Europe (GME), Latin America (GMLAAM), and Asia Pacific (GMAP)].
The material designation is defined by the GMW base metal
specification number, steel product type, minimum yield strength,
and finish type. The steel product type is designated by CR for
cold rolled products, or HR for hot rolled products. A numeral
(180, 210, 240, etc.) will designate the minimum yield strength
level in megapascals (MPa). A designation of steel type shall be
added to bake hardenable (B0 and B2), solid solution strengthened
grades (P and IF), and high strength low alloy (LA) steels as shown
in section 8. The dual phase (DP) grades have been removed from
this specification and are now covered by equivalent grades in
GMW3399. GMW3032M-ST-S CR550 has been deleted from this
specification and has been replaced by GMW3399M-ST-S CR690T/550Y
DP. An "F" designation may be added on engineering and/or
manufacturing documents following an LA steel type to specify the
steel as inclusion-controlled
(See Appendix A).
Typical applications are coated or uncoated sheet metal parts consisting of high strength sheet steel with specified minimum yield strengths from 180 MPa through 700 MPa.