双轴加载下不同氢含量锆合金变形行为及数值模拟

Biaxial cyclic deformation behavior of hydrided zircaloy-4 has been studied. Hydride in Zr-4 has deformability epending on its distribution and morphology. The non-proportional cyclic softening was displayed in Zr-4 at stress-relieved condition, whereas, additional cyclic hardening was exhibited at recrystallized condition. The higher the additional hardening degree, the lower the fatigue lifetime is. Additional cyclic hardening results from strengthening of interaction between dislocations due to activation of multi-slips and increasing of the critical resolve shear stress for prism slip system. Additional cyclic softening can be explained by disappearing of directional hardening mechanism when the loading mode changes from proportional to non-proportional loading. Based on the law of mixture and the large strain axisymmetric elasto-plastic finite element method, the stress strain response of composite containing hydride has been simulated and predicted. A new method of defining the yield behavior of hydrided zircaloy was proposed. The effect of volume fraction, size, distribution of hydride and strain hardening coefficient of matrix on deformation behavior was studied. Our works provide a basic principle to improve the mechanical properties of Zr-4 tube under complex loads, and an instruction to manufacture Zr-4 tube.

研究了不同氢含量锆合金拉-扭加载过程中力学行为及塑变机理。实验观察并理论计算了不αψ刺嘛辖鹉诓炕啤⒙仙⒔饫砜选⑶饣镏麓嘞嗷ブ涞墓叵怠＝馐土孙辖鸱潜壤郊忧炕坝Ρ淅沸вΓ唤⒘撕旯凵夏苊枋鲇αΡ浠⑽⒐凵夏芊从λ鼙浠砑扒饣镄形奈锢硭苄员竟狗匠蹋皇的Ｄ夥蔷什牧细丛佑αψ刺碌母髦至ρ形