盾构切刀硬质合金与钢基体钎焊残余应力

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0.25mm时，刀头应力危险区残余应力最小，160mm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.

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

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 0.25mm， the residual stress in the dangerous area of cutter head stress is the smallest. The number of cemented carbide blocks of 160mm 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.