【摘 要】
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The crack-healing behavior of 50CrVA steel was investigated. The crack was introduce to the 50CrVA by water quenching. The healing process is high temperature multicomponent thermochemical in 750℃ for
【机 构】
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School of Material Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China
【出 处】
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第十一届全国表面工程大会暨第八届全国青年表面工程学术会议
论文部分内容阅读
The crack-healing behavior of 50CrVA steel was investigated. The crack was introduce to the 50CrVA by water quenching. The healing process is high temperature multicomponent thermochemical in 750℃ for 2.5h combined with low temperature multicomponent thermochemical in 670℃ for 5h. The steel 50CrVA specimens after healing were investigated by metallographic microscope, scanning electron microscope (SEM), X-ray diffraction(XRD) and mechanical properties testing. After the healing process,the crack met and some voids and oxide were left. During the process,columnar crystal was formed in both sides of the meet line. The results show that mechanical properties of 50CrVA after crack healing improved than before. Microhardness after crack healing is close to the Microhardness of substrate material. Impact properties after crack healing are even close to the impact properties of specimens with no crack after same multicomponent thermochemical treatment process.,reached a impact absorbing energy of 140J. And after crack healing, tensile strength doubled.The mechanism of crack healing in 50CrVA has been discussed. The crack healing process mainly depends on volume expansion and atoms diffusion.
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