摘要
开展了不同应力三轴度下的S30408不锈钢单轴拉伸试验和微观组织研究,分析了应力状态对其强度的影响,结合扫描电子显微镜(SEM)和X射线衍射分析(XRD)探究了断口形貌及析出相变化规律。基于Hollomon本构方程和Swift模型开展了S30408变形行为分析,实现了不同缺口状态下S30408不锈钢真实应力-真实应变关系的合理评价和准确预测。研究结果表明:S30408不锈钢的屈服强度和极限强度随着应力三轴度的增加而增加,断后延伸率则呈现下降趋势,断口均呈现出显著的韧性断裂特征,且存在明显的马氏体相变。以此为基础,建立了应力三轴度系数与材料力学性能之间的关系,提出了考虑应力状态的Swift修正模型,实现了对不同应力三轴度下S30408不锈钢变形行为的合理评价。
The uniaxial tensile test and microstructure study on S30408 stainless steels under different stress tri-axial degrees were carried out,including the analysis of the stress influence on the strength.Through scanning electron microscopy(SEM)and X-ray diffraction(XRD)analysis,both fracture morphology and precipitation phase change rules were explored.In addition,based on the Hollomon constitutive equation and Swift model,the S30408 stainless steel’s deformation behavior was analyzed,including the realization of the reasonable evaluation and accurate prediction of its real strain-curve of the stress and strain under different notch states.The results show that,S30408 stainless steel’s yield strength and ultimate strength would increase with the increase of triaxial degree of the stress and its elongation of extrusion bar after forging process shows a decreasing trend;meanwhile,its fractures show significant ductile fracture characteristics and an obvious martensite transformation can be found.Based on it,the relationship between stress triaxiality coefficient and mechanical properties of materials can be established and the Swift modified model which considering the stress state was proposed to realize S30408 stainless steel’s reasonable evaluation of the deformation behavior at different stress triaxiality.
作者
张涛
夏雨
蒋莉莉
周云
ZHANG Tao;XIA Yu;JIANG Li-li;ZHOU Yun(Special Equipment Safety Supervision Inspection Institute of Jiangsu Province)
出处
《化工机械》
2025年第4期546-553,共8页
Chemical Engineering & Machinery
关键词
S30408不锈钢
应力三轴度
马氏体相变
本构模型
S30408 stainless steel
stress triaxiality
martensitic transformation
constitutive model
