Microstructure and mechanical properties of a hot pressing-dynamic partition treated steel

Abstract

The microstructure and mechanical property of improved press-hardened steel with hot pressing combined dynamic partitioning (HP-DP) treatment are presented. Microstructure of the steel subjected to HP-DP treatment is featured by multi-martensite phases and the retained austenite (RA) phase with carbon content gradient. Compared with conventional hot-pressed samples, the HP-DP samples show better tensile property especially ductility. The effect of HP-DP parameters on the evolution of RA and mechanical property is then discussed. Finally, hot pressing of a double U-shaped part using both 22MnB5 steel sheet and the developed HP-DP steel sheet was carried out with exact control of part temperature at the end of hot pressing followed by air cooling.

Effect of Finish Rolling Temperature on Microstructure and Mechanical Properties of Low-Si Steel After Quenching and Nonisothermal Partitioning

“…The initial work on this quenching and nonisothermal partitioning process was reported by Thomas et al in 2009 [14]. Thereafter, some other researchers, including the present authors, have also investigated the various aspects of this energy-efficient quenching and nonisothermal partitioning process [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30]. These studies have shown to achieve the desired microstructural combination [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] and, therefore, improved mechanical properties, in comparison to the steel treated by direct quenching [19,23], quenching and tempering [21], and quenching and isothermal partitioning process [14,15,17,18], within similar alloy compositions.…”

Microstructural and mechanical properties of ultra-high-strength dual-phase steel produced by ultra-fast cooling

“…Dual-phase (DP) steel is an ideal material for automobile chassis, reinforcing plates and bumpers owing to its high strength, toughness, low yield ratio, strength-plastic matching and excellent forming performance. The simultaneous increase in steel strength and reduction in thickness is an effective way to reduce the weight of automobiles and improve the stability as well as safety of automobile operation [3][4][5].…”