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采用大型有限元分析软件SYSWELD建立了三维有限元模型,对轧辊搭接激光熔凝过程进行了数值模拟,考察了搭接激光熔凝的热循环和温度变化率,分析了不同搭接量对材料熔凝层的相变和残余应力的影响。结果表明,轧辊经过搭接激光熔凝后,搭接区经历两次激光扫描成为二次重熔区,搭接区边界带发生了回火;随着搭接量增大,熔凝层的宽度变窄,但对熔凝-相变区马氏体组织含量的影响不大,其马氏体体积分数都超过了90%;熔凝-相变区获得较大的压应力,热影响区为拉应力。改变搭接量不能消除拉应力,但是选择合适的搭接量,能使拉应力幅值减小。在该实验条件下,选择3 mm的搭接量,能获得较理想的应力分布,并与工艺试验结果进行了比较,轧辊表面轴向残余应力计算结果和实验测量值基本吻合。
The finite element analysis software SYSWELD was used to establish a three-dimensional finite element model. The laser lap welding process was simulated numerically. The thermal cycling and temperature change rate of lapped laser cladding were investigated. Melting layer of the phase transition and residual stress. The results show that the lap area undergoes two laser scanning processes to become the secondary remelting area after lapped laser melting, and the boundary zone in the lap area is tempered. With the increase of the lapped amount, the width of the fused layer But it has little influence on the martensite content in the melting-transformation zone, and its martensite volume fraction exceeds 90%. Larger compressive stress is obtained in the melting-transformation zone, and the heat affected zone is Tensile stress. Change the amount of lap can not eliminate tensile stress, but choose the appropriate amount of lap, can make the tensile stress amplitude decreases. Under this experimental condition, the optimal stress distribution can be obtained by choosing a lapping amount of 3 mm, which is compared with the experimental results. The calculation results of the axial residual stress on the roller surface are in good agreement with the experimental values.