盾构切刀硬质合金与钢基体钎焊残余应力  

Residual Stress in Soldering and Brazing Between Cemented Carbide and Steel Substrate of Shield Machine Cutters

作　　者：夏毅敏[1] 仝磊 柏彬 华伟明 XIA Yi-min;TONG Lei;BAI Bin;HUA Wei-ming(College of Mechanical&Electrical Engineering,Central South University,Changsha 410083,China;Ministry of Construction,State Grid Jiangsu Electric Power Company,Nanjing 211000,China)

机构地区：[1]中南大学机电工程学院,湖南长沙410083 [2]国网江苏省电力有限公司建设部,江苏南京211000

出　　处：《东北大学学报（自然科学版）》2020年第1期101-107,共7页Journal of Northeastern University(Natural Science)

基　　金：国家高技术研究发展计划项目(2012AA041803);湖南省战略性新兴产业科技攻关项目(2015GK1029);国家电网公司科技项目(JSJS1600326)

摘　　要：针对盾构切刀容易出现焊接裂纹以及残余应力过大导致刀具切削时合金容易剥落的难题,建立了切刀钎焊热力耦合过程有限元分析模型,通过模拟计算和X射线衍射仪对残余应力进行试验验证,研究不同焊接结构切刀的钎焊温度场和残余应力场.研究结果表明,切刀刀头钎焊后冷却过程中温度场呈现梯度分布.当钎料厚度为0.25 mm时,刀头应力危险区残余应力最小,160 mm刃宽切刀的合金块数设计为3块可降低焊接残余应力、提高焊接强度.残余应力试验结果与数值模拟结果趋势基本吻合,钢基体表面为压应力.Aiming at the problem that shield machine cutters are prone to welding cracks and the residual stress is too large,which leads to the alloy spalling easily in the cutting process of cutters,the finite element analysis model of the brazing process of cutters was established,and the brazing temperature field and residual stress field of cutters with different welding structures were studied through simulation calculation and X-ray diffractometer experimental verification.The results show that the temperature field presents a gradient distribution in the cooling process after brazing the cutter head.When the thickness of the solder is 0.25 mm,the residual stress in the dangerous area of cutter head stress is the smallest.The number of cemented carbide blocks of 160 mm blade width cutters is designed as 3 pieces to reduce welding residual stress and improve welding strength.The results of residual stress test are basically consistent with the numerical simulation results,and the surface of steel matrix is compressive stress.

关 键 词：盾构切刀 硬质合金 钢基体 钎焊 残余应力 

分 类 号：TG454[金属学及工艺—焊接]