1 School of Materials Science and Engineering, Shanghai University, Shanghai 200072, China 2 State Key Laboratory of Advanced Special Steel, Shanghai University, Shanghai 200072, China 3 Pangang Group Research Institute, Panzhihua 617000, Sichuan, China
In-situ analysis of retained austenite transformation in high-performance micro-alloyed TRIP steel
1 School of Materials Science and Engineering, Shanghai University, Shanghai 200072, China 2 State Key Laboratory of Advanced Special Steel, Shanghai University, Shanghai 200072, China 3 Pangang Group Research Institute, Panzhihua 617000, Sichuan, China
ժҪ Microstructures and mechanical properties of Ti-V micro-alloyed TRIP (transformation-induced plasticity) steel with different compositions were investigated by tensile test, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and thermodynamic calculation (TC). The results indicated that the steel exhibited high ultimate tensile strength (1079 MPa), sufficient ductility (28%) and the highest product of strength and ductility (30212 MPa?%) heat treated after intercritical annealing at 800��C for 3 min and bainitic annealing at 430��C for 5 min. In addition, the change of volume fraction of retained austenite (VF-RA) versus tensile strain was measured using in-situ analysis by X-ray stress apparatus and micro-electronic universal testing machine. It was concluded that a-value could be used to evaluate the stability of retained austenite (S-RA) in the investigated Ti-V micro-alloyed TRIP steel. The smaller a-value indicated the higher stability of retained austenite (S-RA) and the higher mechanical properties of Ti-V micro-alloyed TRIP steel.
Abstract��Microstructures and mechanical properties of Ti-V micro-alloyed TRIP (transformation-induced plasticity) steel with different compositions were investigated by tensile test, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and thermodynamic calculation (TC). The results indicated that the steel exhibited high ultimate tensile strength (1079 MPa), sufficient ductility (28%) and the highest product of strength and ductility (30212 MPa?%) heat treated after intercritical annealing at 800��C for 3 min and bainitic annealing at 430��C for 5 min. In addition, the change of volume fraction of retained austenite (VF-RA) versus tensile strain was measured using in-situ analysis by X-ray stress apparatus and micro-electronic universal testing machine. It was concluded that a-value could be used to evaluate the stability of retained austenite (S-RA) in the investigated Ti-V micro-alloyed TRIP steel. The smaller a-value indicated the higher stability of retained austenite (S-RA) and the higher mechanical properties of Ti-V micro-alloyed TRIP steel.
2017, Vol. 24 
