The inclusion and role of micro mechanical residual stress on deformation of stainless steel type 316L at grain level
The inclusion and role of micro mechanical residual stress on deformation of stainless steel type 316L at grain level
复制标题
夹杂物及微机械残余应力对316L不锈钢晶粒级变形的影响
DOI：
10.1016/j.msea.2023.145096
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Horton E
中科院分区：
文献类型：
--
作者：
Horton E
验证晶体塑性模型需要仔细考虑各个方面。在比较模型和实验时，初始条件很重要，因为材料内的初始残余应力可能很大，但由于实验限制常常被忽视。因此，它们的包含有可能改善模型预测。这项工作探讨了使用高分辨率电子背散射衍射 (HR-EBSD) 测量的 III 型残余弹性应力作为 316L 不锈钢中的预测试应力分布的功效。使用了两种处理收集的应力的方法（直接方法和使用最小二乘解算器）。使用现有方法将实验测量值合并为初始残余应力；将模型结果与不含残余应力的模型和实验结果进行比较。最小二乘法有助于消除通过互相关法在平均角度误差较高的点计算出的极端应力。直接模型和最小二乘模型的模拟应力分布与实验观察到的应力并不完全匹配，但在一些晶粒中可以看到相似之处。加载后，无论是否包含残余应力，模型之间几乎没有什么差异，这意味着对材料变形响应的影响可以忽略不计。然而，预测的应力分布与变形后实验测量的应力分布不匹配，这表明在晶体塑性模型中必须考虑进一步的物理效应。
Validating crystal plasticity models requires careful consideration of all aspects. The initial conditions are important when comparing a model and experiment, as the initial residual stresses within the material can be significant but are often overlooked due to experimental limitations. Therefore, their inclusion has the potential to improve model predictions. This work explores the efficacy of using type-III residual elastic stresses, measured using high resolution electron backscatter diffraction (HR-EBSD),as pre-test stress distributions in 316L stainless steel. Two methods of processing the stresses collected (direct and using a least squares solver) were used. A existing method was used to incorporate the experimental measurements as initial residual stresses; The model results were compared with each other, a model containing no residual stress and the experiment. The least squares method helped remove extreme stresses calculated by the cross-correlation method at points with high mean angular error. The modelled stress distributions from both the direct and least squares model did not fully match the experimentally observed stresses but similarities were seen within some grains.After loading, little difference was seen between the models, with and without the inclusion of residual stress, implying a negligible effect on the deformation response of the material. However, the predicted stress distribution did not match with the experimentally measured stress distribution after deformation, suggesting further physical effects must be accounted for in crystal plasticity models.