一、前言 屈服应力是在金属材料拉伸试验中测得的五大力学性能指标之一,由于许多金属及其合金没有明确的物理屈服点,因而一些国家自行规定了条件屈服应力的定义及测试方法。如ISO标准中规定以总伸长验证应力Rt、残余伸长应力Rr和非比例伸长应力R_p等作为屈服应力指标。我国瞬时拉伸试验方 I. Preface Yield stress is one of the five mechanical properties measured in the tensile test of metallic materials. Since many metals and their alloys do not have a definite physical yield point, some countries define their own conditions of yield stress definition and test methods . Such as the provisions of the ISO standard to verify the total elongation stress Rt, residual elongation stress Rr and non-proportional elongation stress R_p as a yield stress index. China’s instantaneous tensile test side