激光氮化过程中产生的拉伸热应力,是导致氮化层开裂和性能下降的重要原因。通过建立三维有限元模型,分析工艺热应力的分布规律,发现危险的最大拉伸热应力出现在氮化层与基体结合处,并且更容易以纵向裂纹的形式释放。进一步基于基体约束作用和工艺环境对热应力的影响,提出了降低拉伸热应力、改善氮化质量的两种工艺方案:基体预热和外施载荷,为激光氮化工艺的推广和工业应用奠定基础。 The tensile thermal stress generated during the laser nitriding is an important reason for the delamination and degradation of the nitride layer. Through the establishment of the three-dimensional finite element model, the distribution of thermal stress in the process is analyzed. It is found that the dangerous maximum tensile thermal stress occurs at the junction of the nitride layer and the matrix and is more easily released in the form of longitudinal cracks. Based on the effect of matrix restraint and the influence of process environment on thermal stress, two process schemes were proposed to reduce the tensile thermal stress and improve the quality of nitriding: substrate preheating and applied load, which are the promotion and industrial application of laser nitriding technology Lay the foundation.