轧辊搭接激光表面熔凝数值分析  

Finite Elements Analysis of Overlapping Ratios of Laser Surface Melting on Roller

作　　者：黎超文[1] 王勇[1] 韩涛[1] 韩彬[1] 

机构地区：[1]中国石油大学(华东)机电工程学院材料科学与工程系,山东东营257061

出　　处：《中国激光》2010年第7期1861-1867,共7页Chinese Journal of Lasers

基　　金：山东省自然科学基金(Y2006F64;ZR2009EM030);中国石油大学(华东)博士创新基金(B2009-13)资助课题

摘　　要：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。With the SYSWELD finite element code,a three-dimensional finite element model has been developed to apply for analysis of overlapping laser surface melting on roller.The thermal circle and temperature rate of overlapping laser melting were investigated and the phase transformation and residual stress fields were analyzed.It is found that overlapping area becomes second melted and the boundary of overlapping area exists tempering for twice laser scanning after overlapping laser surface melting on roller.With the increase of the overlapping ratios,the width of the laser melted layer becomes smaller,while the martensite contents are independent on the overlapping ratios and exceeds 90% in the melt-hardened zone.The residual stress distributed within the melt-hardened zone is mainly of the compressive type,while there is the tensile stress in the heat-affected zone.The tensile stress cannot be eliminated by changing overlapping ratios,but the tensile stress amplitude can be reduced by choosing the proper overlapping ratios.The ideal stress distribution can be obtained by choosing 3 mm overlapping ratio under these experimental conditions.The comparisons between the calculated results with the experimental measured values show a good agreement for axis residual stresses.

关 键 词：激光技术 激光熔凝 有限元方法 搭接 相变 残余应力 

分 类 号：TN249[电子电信—物理电子学] TG156.99[金属学及工艺—热处理]