LOW CARBON-HIGH MANGANESE STEEL AND MANUFACTURING PROCESS THEREOF

摘要

A low carbon-high manganese steel sheet and process for manufacturing the sheet is provided. The process includes soaking a steel slab with a desired chemical composition within a temperature range of 1200-1350° C., followed by hot rolling of the slab into hot strip. The cold rolled sheet is continuously annealed within a temperature range of 730-850° C. and temper rolled between 1.0-2.0%. The temper rolled sheet has a yield strength greater than 280 megapascals (MPa), a tensile strength greater than 400 MPa, an elongation to fracture greater than 30%, an n-value greater than 0.15, and a bakehard index between 15-35 MPa.

主权项

1. A process for making a low carbon-high manganese steel sheet, the process comprising:
providing a steel slab having a chemical composition within a range in weight percent of 0.04-0.10 C, 0.80-1.65 Mn, 0.5 max Si, 0.40 max Cr, 0.10 max Nb, 0.03 max Ti, 0.003 max V, 0.20 max Mo, 0.10 max Ni, 0.015 max S, 0.05 max P, 0.012 max N, 0.003 max B, and 0.015-0.065 Al, with the balance being Fe and incidental impurities; soaking the steel slab within a temperature range of 1200-1350° C.; hot rolling the soaked steel slab using a roughing treatment and producing a transfer bar; hot rolling the transfer bar using a finishing treatment and producing hot rolled strip; cold rolling the hot rolled strip and producing cold rolled sheet with a reduction in thickness ranging between 50-80%; continuous annealing the cold rolled sheet within a temperature range of 730-850° C.; and temper rolling the annealed cold rolled sheet between 1.0-2.0%, the temper rolled sheet having a yield strength greater than 280 MPa, a tensile strength greater than 400 MPa and an elongation to fracture greater than 30%.