20Cr2Ni4齿轮钢激光喷丸和机械喷丸残余应力场有限元模拟

Finite element simulation of residual stress field of 20Cr2Ni4 gear steel by laser shock peening and shot peening

使用有限元软件建立了20Cr2Ni4齿轮钢喷丸强化的三维数值分析模型,探究了激光喷丸(LSP)与机械喷丸(SP)在不同工艺参数下的残余应力场,分析了网格尺寸对模拟结果的影响,建立了复合喷丸的有限元网格模型,研究了不同复合方式的喷丸对残余应力场的影响。结果表明,激光喷丸有限元分析中,网格尺寸一般控制在0.1 mm以下,相较于激光喷丸,机械喷丸对网格密度的要求比较高。当弹丸直径为Φ0.5 mm,且冲击区域最小单元网格尺寸为0.03 mm以下时,模拟结果有效。相较于激光喷丸,LSP-SP复合喷丸在表面产生的残余压应力略有提升,应力在靶材表面没有被严重的削弱。复合喷丸的残余压应力层深可以达到机械喷丸的2~3倍;在深度方向的最大残余压应力可以达到材料屈服强度的1.5倍。

The three-dimensional numerical analysis model for shot peening strengthening of 20Cr2Ni4 gear steel was established by finite element software,the residual stress fields of laser shock peening(LSP)and shot peening(SP)with different process parameters were investigated,the influence of mesh size on the simulation results was analyzed,the finite element mesh model of composite shot peening was established,and the influence of SP with different composite modes on the residual stress field was studied.The results show that in the finite element analysis of LSP,the mesh size is generally controlled within 0.1 mm.Compared with LSP,SP requires higher grid density.When the diameter of the projectile is Φ0.5 mm and the minimum mesh element size in the impact area is 0.03 mm or less,the simulation results are effective.Compared with LSP,the residual compressive stress on the surface of LSP-SP composite shot peening is slightly higher,and the stress on the target surface is not seriously weakened.The depth of residual compressive stress layer of composite shot peening can reach 2-3 times of that of SP,the maximum residual compressive stress in the depth direction can reach 1.5 times of the yield strength of the material.