摘要
对304不锈钢600℃下的非比例循环棘轮行为进行了系统的实验研究,在统一粘塑性循环本构模型的框架下对其进行本构描述.模型中,通过随动硬化背应力演化和各向同性变形阻力演化,对304不锈钢在非对称应力循环下的循环附加硬化和循环流动特性进行模拟.在等温条件下,在各向同性变形阻力演化方程中引入温度项来考虑温度效应.在随动硬化背应力演化方程中引入动态恢复项的衰减系数,反映材料在特定温度范围(500～600℃)下特殊的背应力动态恢复特征.定义了一个新的非比例因子,讨论了非比例加载路径对棘轮行为的影响.引入最大应变幅值衰减记忆函数 (q)和最大各向同性变形阻力衰减记忆系数ω反映加载历史对循环棘轮行为的影响.将模型应用于304不锈钢高温多轴循环棘轮行为及其对加载历史依赖性的描述中,预言结果与实验结果吻合较好.
In the unified visco-plastic cyclic constitutive model, the rate dependence of material was reflected by a viscous term. The cyclic hardening and cyclic flow behaviors of 304 stainless steel under asymmetrical stress-controlled cycling were analyzed by the evolution rules of kinematic hardening back stress and isotropic deforming resistance. In the isothermal condition, the effect of temperature was introduced by temperature terms in evolution equations of isotropic deforming resistance. The special dynamic recovery characteristics of the back stress evolution appeared at a specific temperature range of 500-600°C were reflected by fading factor. A new proportional factor was introduced into the model in order to consider the effect of loading path shape on the multiaxial ratcheting. The effect of load history on the ratcheting was also considered by introducing a fading memorization function for the maximum inelastic strain amplitude and isotropic deformation resistance of the loading history. With the material constants determined by experiment, the multiaxial ratcheting of 304 stainless steel was numerically simulated at 600°C. It is shown that the predicted results agree well with the experimental ones.
出处
《核动力工程》
EI
CAS
CSCD
北大核心
2002年第3期22-29,共8页
Nuclear Power Engineering
基金
国家自然科学基金项目(19772041)
四川省跨世纪青年学科带头人培养基金
