摘要
提出通过测量磁处理过程中的磁致应变来反映磁场对残余应力作用规律的研究思路。通过TIG焊表面重熔和不同热处理规范加工初始应力水平不同的45钢试块,测量这些试块在相同低频间歇磁场作用下的磁致伸缩曲线,比较磁场作用前后残余应力的变化。试验结果表明,不同初始应力水平的试块在磁处理过程中表现出不同的磁致伸缩行为,而磁处理过程中磁致伸缩的相对变化与残余应力的相对变化具有良好的对应关系,通过磁致伸缩曲线可以判断出残余应力变化的大小及是否已趋于稳定。在试验现象的基础上,从能量微分方程建立的磁致伸缩应变量与应力水平间的对应关系,结果显示脉冲磁场作用下磁致伸缩幅值与主应力的乘积为常量,与试验值很吻合。
Residual stress caused by magnetic field treatment is studied through magnetostriction investigation.The external magnetic field is carried out for both stress relief and magnetostriction at the same time.Samples of steel 45 are produced by tungsten inert gas welding and different heat treatment temperature and time are used to modify stress levels.The magnetostriction in the magnetic treatment process is recorded and residual stresses before and after the action of magnetic are compared.Experiment results shows that magnetostriction behaviors with different stress levels are different obviously.However,a good coherence exists between the relative change of magnetostriction and that of residual stress.Thus residual stress relief during the magnetic treatment can be evaluated by magnetostriction investigation conveniently.To explain the relationship between magnetostriction and stress level,energy differential equations are constructed and energy boundary conditions are modeled.The results deducted from the established equations show that the product of magnetostriction variation caused by pulsed magnetic field and residual stress in macro scope is constant,which agrees well with experiment results.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2010年第22期36-40,共5页
Journal of Mechanical Engineering
基金
清华大学先进成形制造教育部重点实验室开放基金(2008008)
国家自然科学基金(50805085)资助项目
关键词
磁致伸缩
残余应力
磁处理
Magnetostriction Residual stress Magnetic treatment
