HIGH-STRENGTH MULTIPHASE STEEL AND METHOD FOR PRODUCING A STRIP MADE FROM THIS STEEL WITH A MINIMUM TENSILE STRENGTH OF 580 MPA

摘要

The invention relates to a high-strength multiphase steel with minimum tensile strengths of 580 MPa, preferably a dual-phase structure for a cold-rolled or hot-rolled steel strip with improved forming properties, particularly for lightweight vehicle construction. The multiphase steel consists of the elements (contents in mass-%): C 0.075 to <= 0.105; Si 0.600 to <= 0.800; Mn 1.000 to <= 2.250; Cr 0.280 to <= 0.480; AI 0.010 to <= 0.060; P <= 0.020; N <= 0.0100; S <= 0.0150, remainder iron, including typical steel-accompanying elements not mentioned above, which are impurities introduced by smelting, with the condition that the Mn content is preferably <= 1.500% for strip thicknesses up to 1 mm, the Mn content is preferably <= 1.750% for strip thicknesses of 1 to 2 mm, and the Mn content is preferably >= 1.500% for strip thicknesses >= 2 mm.