Intercritical annealing(IA) at various temperatures followed by quenching and partitioning(IAQP) treatments was conducted on a cold-rolled Fe-0.2C-1.42Si-l.87Mn(wt%) sheet steel.Optimized microstructure and enha...Intercritical annealing(IA) at various temperatures followed by quenching and partitioning(IAQP) treatments was conducted on a cold-rolled Fe-0.2C-1.42Si-l.87Mn(wt%) sheet steel.Optimized microstructure and enhanced mechanical properties were achieved through appropriate adjustment of IA temperatures.The steel which was annealed at1,033 K for 600 s,then quenched to 573 K and partitioned at 693 K for 20 min,designated as 1033 QP steel,exhibits maximum 16.3 vol% retained austenite(RA) with good mechanical properties(ultimate tensile strength 886 MPa and total elongation 27%).It was found that the thermal and mechanical stabilities of RA are mainly influenced by the combined effect of its average carbon content and amount of adjacent martensite.Furthermore,the transformation-induced plasticity effect increased the peak n-values observed at the second stage of the work hardening of IAQP steels.展开更多
基金financially supported by the National Natural Science Foundation of China (No. 51174251)the National Basic Research Program of China (No. 2010CB630803)
文摘Intercritical annealing(IA) at various temperatures followed by quenching and partitioning(IAQP) treatments was conducted on a cold-rolled Fe-0.2C-1.42Si-l.87Mn(wt%) sheet steel.Optimized microstructure and enhanced mechanical properties were achieved through appropriate adjustment of IA temperatures.The steel which was annealed at1,033 K for 600 s,then quenched to 573 K and partitioned at 693 K for 20 min,designated as 1033 QP steel,exhibits maximum 16.3 vol% retained austenite(RA) with good mechanical properties(ultimate tensile strength 886 MPa and total elongation 27%).It was found that the thermal and mechanical stabilities of RA are mainly influenced by the combined effect of its average carbon content and amount of adjacent martensite.Furthermore,the transformation-induced plasticity effect increased the peak n-values observed at the second stage of the work hardening of IAQP steels.