摘要
为了揭示高频振动时效消除残余应力的微观机理,探讨了高频振动载荷作用下的位错密度演化特性对残余应力松弛的影响规律。分别采用Williamson-Hall(WH)法和小孔法分析高频振动前后Cr12MoV钢淬火试样的位错密度和残余应力。在实验研究的基础上,采用微观动力学理论,建立晶粒多自由度系统,分析高频振动激活位错运动的机制,进一步采用晶体塑性理论,建立高频振动作用下的位错密度演化控制方程,分析高频振动时效消除残余应力的微观机理。结果表明:材料内的位错在高频振动的作用下激活运动,产生位错累积和位错湮灭2个演化过程,其中材料内的位错湮灭过程占据主导地位,从而降低了材料内的位错密度;位错密度的降低减小了材料内的晶格畸变程度,从而松弛了材料内的残余应力。
In order to reveal the mechanism of the high-frequency vibratory stress relief, the effect of the evolution of the dislocation density with the help of high-frequency vibration on the residual stress relaxation was studied. The Williamson-Hall （WH） method and the hole-drilling method were used to evaluate the dislocation densities and the residual stresses in the Crl2MoV steel quenched specimens before and after high-frequency vibration. Based on the experimental results, the multi-freedom system of the crystal grain was developed based on the microscopic dynamics theory in order to analyze the mechanism of high-frequency vibration activated dislocation motion. In addition, the governing equation of the dislocation density evolution with the aid of high-frequency vibration was proposed in order to reveal the microcosmic mechanism of the high-frequency vibratory stress relief. The results show that the dislocations inside the materials are activated with the help of high-frequency vibration. The dislocation density evolution process mainly consists of the dislocation accumulation process and the dislocation annihilation process. And the dislocation annihilation is dominant with the help of high-frequency vibration, and thus the dislocation density inside the materials can be reduced. The degree of the lattice distortion can be reduced due to the decrease of the dislocation density. As a result, the residual stress inside the materials can be relieved by the high-frequency vibratory stress relief.
作者
顾邦平
胡雄
徐冠华
赖金涛
潘龙
Gu Bangping;Hu Xiong;Xu Guanhua;Lai Jintao;Pan Long(Shanghai Maritime University,Shanghai 201306,China;Zhejiang Province Key Laboratory of Advanced Manufacturing Technology,Zhejiang University,Hangzhou 310027,China;Zhejiang University Kunshan Innovation Institute,Kunshan 215347,China;Kunshan Industrial Technology Research Institute Co.Ltd,Kunshan 215347,China;Shaoxing University,Shaoxing 312000,China)
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2018年第8期2477-2482,共6页
Rare Metal Materials and Engineering
基金
国家高技术研究发展计划("863"计划)(2013A2041106)
江苏省自然科学基金青年基金(BK20150397)
中国博士后科学基金面上资助项目(2016M591799)
国家自然科学基金青年基金(51605303)
关键词
高频振动时效
位错密度
残余应力
位错湮灭
high-frequency vibratory stress relief
dislocation density
residual stress
dislocation annihilation
