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采用切割法,用应变片测定了钢轨纵向残余应力.并研究了主要工艺因素如冷却,矫直方式(立矫、卧矫),矫直次数,矫直变形量以及淬火等对钢轨残余应力的影响.试验结果表明,钢轨轧后冷却过程中产生的残余应力主要由热应力造成,其值不大.普通轨中的残余应力取决于矫直过程.增加矫直次数不会增加钢轨中的残余应力.矫直过程产生残余应力的机理是复杂的,除弯曲变形外,还必须考虑沿钢轨轴向产生的缩短变形.全长淬火轨经卧矫后,在轨头踏面仍保持了较大的压缩残余应力,这对于提高钢轨的疲劳强度是有利的.
Using the cutting method, the longitudinal residual stress of the rail was measured by the strain gauge, and the effects of the main process factors such as cooling, straightening method (straightening, lying correction), straightening times, straightening deformation and quenching on the residual stress The results show that the residual stress produced during the cooling process after rail rolling is mainly caused by thermal stress and its value is not large.The residual stress in normal rail depends on the straightening process.The increase of straightening times will not increase the residual in the rail Stress. The mechanism of residual stress during straightening process is complicated. In addition to the bending deformation, shortening deformation along the rail axis must be taken into account. After full-length quenching, Residual compressive stress, which is to improve the fatigue strength of the rail is beneficial.