为提高热处理后钢轨焊接接头平直度的控制精度,实验分析实际生产工艺和不同支撑条件下钢轨焊接接头分别静茕20 h及30 d时上拱量及残余应力的变化.结果表明,当2 m长钢轨焊接接头试样的轨顶温度从55℃冷却到室温25℃时,其上拱的减小最约为0.1 mm;在自由放置状态、支撑两边和支撑中间3种支撑条件下,试样的变形量相似;试样在不同支撑条件下放置30 d后的上拱鲢变化较温度引起其上拱量的变化小若干倍;试样的轨顶及轨底主要承受轴向压应力,量值约在-300～-150 MPa范围内;在不同支撑条件下,室温静置30 d后试样的残余应力无明显变化;在实际生产中,将热处理后的钢轨焊接接头放置8～10 h可以完伞满足矫形、精磨等后道工序的要求.%To improve the control accuracy for the perceived level-straight quality of the welded rail joints after the heat treatment, tests were carried out to analyze the variations of the arch height and the residual stress of the welded joints with actual production technique and different supporting conditions 20 hours and 30 days respectively after welding. The results indicate that the arch height of the 2 m long welded rail joint decreases about 0. 1 mm during the cooling of the rail top from 55 to 25 ℃. The deformations are similar under three different supporting conditions, including no gravity effect by laying down, decreasing arch height by supporting two ends and increasing arch height by supporting the joint middle. Compared with the influence of temperature, the arch variations caused by different supporting conditions are smaller by several times, even after 30 days. The residual stresses of the rail top and bottom are in compressive states and the stress values are from -300 to -150 MPa. There is no obvious stress change under different supporting conditions after 30 days laying at room temperature. Thus, to lay the welded rail joints for 8～10 hours after the heat treatment can meet the requirements for the follow-up working procedures,such as the rectification and exact grinding in practical production.
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