Yao Y.,Tsinghua University |
Yao Y.,Key Laboratory of Advanced Forming and Manufacturing |
Qiao S.,Tsinghua University |
Qiao S.,Key Laboratory of Advanced Forming and Manufacturing |
And 6 more authors.
Jinshu Rechuli/Heat Treatment of Metals | Year: 2015
In order to investigate the potential of Q-T and S-Q-P processes on enhancing mechanical properties of medium-high carbon steel, two steels were treated by Q-T, Q-P and S-Q-P processes, respectively. The ultimate tensile strength and total elongation of the samples were obtained on a tensile testing machine. Volume fractions of retained austenite were calculated from XRD spectrum. Microstructure photographs were obtained by SEM. The results show that, compared with Q-T and Q-P processed steels, samples processed by S-Q-P show better mechanical properties. Especially, the product of strength and ductility of higher silicon steel is 3 times higher than that of lower silicon steels. Microstructure analysis indicate that carbon partitioning in S-Q-P process is more thorough. What's more, because of the inhibiting effect of silicon on bainite transformation during partitioning process, S-Q-P processed medium-high carbon steels display much more favorable mechanical properties. In addition, the test results proves the Q-P process to be ineffective in improving mechanical properties of medium-high carbon steels, probably because much austenite transform into bainite during partitioning. © 2015, Chinese Mechanical Engineering Society of Heat Treatment. All right reserved.