New Process of Hot Stamping in Combination with Q-P-T Treatment for Higher Strength-Ductility Auto-Parts

摘要

Hot stamping has been developed into a sophisticated stage with standardized technology and typical product USIBOR 1500.Most of the hot stamped components from 22MnB5 blanks possess high strength-ductility with TS·El product from 10 to 15 GPa％.To meet the further requirement of automakers on body lightening,energy saving and impact safety, the new HFQPT process is proposed, i.e.Hot Stamping in combination with Quenching-Partitioning-Tempering treatment, for higher strength-ductility auto parts with TS·El product 20～30GPa％.Based on the key technology of AHSS in retained austenite RA and TRIP effect, the Q-P-T treatment is integrated to hot stamping process to obtain retained austenite on the martensite matrix to improve ductility of hot stamped ultra-high-strength components.A low temperature P-T furnace is added to the hot stamping line followed the hot pressing machine to perform Partitioning-Tempering treatment immediately after Hot Press Forming and Quenching, named as HFQPT process.The blank steels for new hot stamping process HFQPT line can be further developed on the basis of low alloyed TRIP assisted steels, Q-P steels and Q-P-T steels, and produced in traditional hot strip mill HSM or in compact steel production CSP line through thin slab casting &direct rolling to deliver ultra-thin-hot-strip (thickness t =1.2 ～2.0 mm).