42CrMo钢激光冲击诱导残余应力的数值模拟

42Cr Mo钢具有较高的强度和韧性,被广泛应用于装备制造行业。本文以42Cr Mo钢为研究对象,在理论分析的基础上,运用ABAQUS数值模拟的方法,探讨了在相同激光能量(4J)和脉冲宽度(8ns)情况下,不同光斑直径(1mm、2mm、3mm、4mm)对激光冲击强化后残余应力分布的影响。结果表明:光斑直径越小,激光诱导冲击波的峰值压力越大,塑性强化层深度越深,表面的最大Von Mises应力值越大;光斑直径过大或者激光诱导冲击波的峰值压力过大,均会影响残余应力的分布;本文的数值模拟条件下,2mm直径的光斑,激光冲击效果最好,与理论分析结果一致。

NUMERICAL SIMULATION OF RESIDUAL STRESS OF 42CrMo STEEL INDUCED BY LASER SHOCK PEENING

42CrMo steel is widely used in equipment manufacturing industry because of its high strength and toughness. In this paper, 42CrMo steel is researched. Based on the theoretical analysis, the effects of different spot diameters (1mm, 2mm, 3mm, 4mm) on the residual stress distribution after laser shock peening at the same laser energy (4J) and pulse width (8ns) are investigated by ABAQUS numerical simulation method. The results show that:the smaller the spot diameter is, the greater the peak pressure of laser induced shock wave is, the deeper the plastic strengthening layer is, and the larger the maximum Von Mises stress on the surface is. Residual stress distribution can be affected by the excessive spot diameter or the large peak pressure of laser induced shock wave. Under the numerical simulation condition of this paper, the laser shock effect of 2 mm diameter spot is the best, which is consistent with the theoretical analysis results.