建筑用热轧奥氏体304不锈钢管力学性能

Mechanics properties of hot-rolled seamless Austenitic 304 stainless steel pipe

为了解热轧无缝不锈钢管材料性能,分别对取材自奥氏体304Φ216×16 mm热轧不锈钢管的光滑和缺口圆棒试件进行单调和循环加载两类试验,获取了应力-应变关系及基本材料参数,得到滞回和骨架曲线,标定钢材循环强化参数,并观察了断面微观破坏特征.研究表明:国产热轧不锈钢管加工工艺对中厚管材性影响不大;奥氏体304不锈钢在循环荷载作用下具有良好强化效应和耗能性能;宜采用随动-等向混合强化材料模型描述其行为,所标定循环强化参数可用于复杂应力状态下的数值模拟;不锈钢材微观破坏特征异于普通低合金或低碳钢.

To study the material behaviors of hot-rolled circle hollow austenitic 304 stainless steel members applied widely in large-span roofs, both smooth and notched round specimens were cut from 304Ф216×16mm mm tubes and tested under monotonic tensile and cyclic axial loadings. Stress-strain curves were obtained to determine basic material parameters as well as load-displacement hysteretic responses and skeleton curves. In addition, fracture micromorphology of the specimens was observed. It is shown that the properties of middle thick austenitic 304 stainless steel are not significantly influenced by hot-rolled forming process. The stainless steel exhibits extensive strain-hardening and higher energy dissipation capabilities under cyclic loadings. As a result, kinematic-isotropic composite hardening material model should be adopted to simulate nonlinear response of this material. Cyclic hardening material parameters are calibrated by test results and used well in the numerical simulations.However, the fracture micromorphology characteristic of the stainless steel is quite different from that of low alloy or carbon steel.