1500 MPa GRADE PRESS HARDENING STEEL BY MEDIUM THIN SLAB CASTING AND DIRECT ROLLING AND METHOD FOR PRODUCING THE SAME

摘要

A press hardening steel by a medium thin slab and having a tensile strength of 1500 MPa or more, includes following components by weight percent: C: 0.21%-0.25%, Si: 0.26%-0.30%, Mn: 1.0%-1.3%, P≤0.01%, S≤0.005%, Als: 0.015%-0.060%, Cr: 0.25%-0.30%, Ti: 0.026%-0.030% or Nb: 0.026%-0.030% or V: 0.026%-0.030% or a mixture of any two or more of the above in any proportion, B: 0.003%-0.004%, Mo: 0.17-0.19% and N≤0.005%. A method for producing the press hardening steel includes following steps: molten iron desulphurization; smelting and refining by an electric furnace or converter; continuous casting; descaling treatment before entering a soaking furnace; hating and soaking; high pressure water descaling before entering a rolling mill; hot rolling; cooling; coiling; austenitizing; die deforming and quenching.