GMW3399M-ST-S HR780T/450Y-DP Dual Phase — Hot Rolled Steel

GMW3399M-ST-S HR780T/450Y-DP is a dual phase grade hot rolled steel conforming to the gm material specifications. At 450 MPa minimum yield strength, this is advanced-strength steel for B-pillar reinforcements, side impact beams, and roof bow structures, with high tensile capacity for safety-critical crash path components requiring controlled collapse behavior.

This specification carries the dual-phase (DP) designation under GMW3399M with ferrite-martensite microstructure for energy absorption in crash structures.

GMW3399M-ST-S HR780T/450Y-DP is classified as a Dual Phase steel at 450 MPa yield and 780 MPa tensile. GMW3399M-ST-S HR780T/450Y-DP at 450 MPa yield uses the dual-phase ferrite-martensite microstructure to deliver high work-hardening rates during forming, which translates to superior crash energy absorption in the finished component.

Ameristeel carries GMW3399M-ST-S HR780T/450Y-DP across a range of gauges and widths in hot rolled form, available as coils, sheets, or custom-cut blanks. With 450 MPa minimum yield strength, this dual phase specification requires precise handling and testing — our ISO 9001:2015 certified processes include third-party laboratory verification on every incoming coil.

GMW3399M-ST-S HR780T/450Y-DP is supplied with the following coating options: hot-dip galvanized (zinc) for general corrosion resistance; galvanneal (zinc-iron alloy) for superior paint adhesion and weldability; electrogalvanized for precise coating weight control and smooth surface finish. At 450 MPa yield, the coating selection for GMW3399M-ST-S HR780T/450Y-DP should account for forming severity and post-stamping corrosion exposure in the final application.

GMW3399M-ST-S HR780T/450Y-DP at 450 MPa yield and 780 MPa tensile compares to GMW3032M-ST-S CR420LA (30 MPa higher yield at 420 MPa) and GMW3032M-ST-S HR420LA (30 MPa higher yield at 420 MPa). Selecting the right grade depends on the balance between strength requirements and forming complexity for your specific stamping application.

GMW3399M-ST-S HR780T/450Y-DP is an OEM-specific grade developed to meet General Motors engineering requirements for vehicle body and structural applications. Ameristeel supplies General Motors-specified steel grades directly to Tier 1 and Tier 2 automotive suppliers throughout Southeast Michigan, with full material traceability and third-party test reports on every coil. Our Fraser, MI steel processing facility maintains dedicated inventory of GMW3399M-ST-S HR780T/450Y-DP to support just-in-time delivery schedules, and our ISO 9001:2015 quality system ensures that every shipment meets the exact mechanical property, surface quality, and dimensional tolerances required by General Motors production standards.

Ameristeel offers in-house processing for GMW3399M-ST-S HR780T/450Y-DP at our Warren and Fraser, Michigan facilities. Available processing capabilities include precision slitting to custom widths on our multi-cut blanking line, cut-to-length sheet processing for exact dimensional requirements, laser cutting of high-strength profiles on our TRUMPF fiber laser with up to 4kW power, shear processing for rapid sheet production. From raw material sourcing through finished part delivery, Ameristeel provides a single-source solution — eliminating the need to coordinate between separate steel suppliers, service centers, and fabrication shops. Learn more about our laser cutting capabilities, production steel sales, or request a quote for processing GMW3399M-ST-S HR780T/450Y-DP to your exact specifications.