应变强化对S30403与S30408不锈钢力学性能影响的对比研究

Comparative Study on Effects of Strain Strengthening on Mechanical Properties of S30403 and S30408 Stainless Steels

研究了应变强化对S30403与S30408奥氏体不锈钢拉伸力学性能影响的差异。结果表明:随着应变强化量的增加,两种不锈钢的屈服强度显著增强,塑性参数明显降低,抗拉强度基本不变;并且两种材料的屈服强度基本一致,抗拉强度、塑性参数以及应变硬化指数存在差异。应变强化后两种不锈钢的力学性能差异与位错、孪晶和马氏体相变量有关。根据力学行为与应变能密度随应变强化量变化的演化规律,构建了改进的Hollomon本构模型,考虑了应变强化量的影响,并由试验结果论证了模型的准确性。

The difference of effects of strain strengthening on the tensile mechanical properties of S30403 and S30408austenitic stainless steels was studied.The results show that with the increase of strain strengthening value,the yield stress of the two stainless steels significantly increase,the plastic parameters obviously decrease,and the ultimate strengths almost unchange.The yield stress of the two materials are basically the same,but there are differences in tensile strengths,plastic parameters and strain hardening exponents.The differences of mechanical properties between the two stainless steels after strain strengthening are related to the dislocation,twin and martensite phase transition.Finally,according to the evolution law of mechanical behavior and strain energy density with the change of strain strengthening value,a modified Hollomon constitutive model considering strain strengthening was constructed,and the accuracy of this model is demonstrated by the experimental results.