The phase transformation characteristics of a high-strength TRIP-aided multiphase cold-rolled steel during continuous heating at different cooling rates were studied by means of dilatometry,and the critical temperatur...The phase transformation characteristics of a high-strength TRIP-aided multiphase cold-rolled steel during continuous heating at different cooling rates were studied by means of dilatometry,and the critical temperatures were also determined.The samples were fully austenitized at 1 050 ℃ and then cooled at different cooling rates ranging from 0.5 ℃/s to 100 ℃/s.The continuous cooling transformation （CCT） curves were obtained for the experimental steel.The experimental results showed that a high cooling rate depressed the formation of ferrite and pearlite and promoted the formation of balnite and martensite,leading to a higher hardness.A large amount of martensite in high-strength TRIP-aided multiphase cold-rolled steel can be obtained at cooling rates in excess of 50 ℃/s.The experimental results provide guidelines for cooling control and heat treatment in real steel production.展开更多
In order to develop a comprehensive understanding about the effect of different holding time under rapid heating on the microstructural evolution and mechanical properties of transformation-induced plasticity （TRIP）...In order to develop a comprehensive understanding about the effect of different holding time under rapid heating on the microstructural evolution and mechanical properties of transformation-induced plasticity （TRIP） steel, continuous annealing process simulations were performed using a thermal system with resistance heating method. The morphology and distribution of all phases present in the microstructure and the mechanical properties of TRIP steel were revealed. It appeared that the final tensile strength of the TRIP steel increased and retained austenite car bon content decreased with increasing holding time. An overlap between ferrite recrystallization and austenitization was observed during intercritical holding. In addition, the work hardening of the samples was evaluated by calculat ing the instantaneous ~l value as a function of the true strain. The difference in work hardening behavior corresponds to the rate of the retained austenite transformation during straining, which can be attributed to the carbon content and the morphology of the retained austenite.展开更多
文摘The phase transformation characteristics of a high-strength TRIP-aided multiphase cold-rolled steel during continuous heating at different cooling rates were studied by means of dilatometry,and the critical temperatures were also determined.The samples were fully austenitized at 1 050 ℃ and then cooled at different cooling rates ranging from 0.5 ℃/s to 100 ℃/s.The continuous cooling transformation （CCT） curves were obtained for the experimental steel.The experimental results showed that a high cooling rate depressed the formation of ferrite and pearlite and promoted the formation of balnite and martensite,leading to a higher hardness.A large amount of martensite in high-strength TRIP-aided multiphase cold-rolled steel can be obtained at cooling rates in excess of 50 ℃/s.The experimental results provide guidelines for cooling control and heat treatment in real steel production.
基金Item Sponsored by National Twelfth Five-year Science and Technology Support Program of China(2011BAE13B01,2011BAE13B03)
文摘In order to develop a comprehensive understanding about the effect of different holding time under rapid heating on the microstructural evolution and mechanical properties of transformation-induced plasticity （TRIP） steel, continuous annealing process simulations were performed using a thermal system with resistance heating method. The morphology and distribution of all phases present in the microstructure and the mechanical properties of TRIP steel were revealed. It appeared that the final tensile strength of the TRIP steel increased and retained austenite car bon content decreased with increasing holding time. An overlap between ferrite recrystallization and austenitization was observed during intercritical holding. In addition, the work hardening of the samples was evaluated by calculat ing the instantaneous ~l value as a function of the true strain. The difference in work hardening behavior corresponds to the rate of the retained austenite transformation during straining, which can be attributed to the carbon content and the morphology of the retained austenite.
