描述不锈钢材料单轴棘轮行为的一元参量体系

基于304不锈钢和1Cr18Ni9Ti不锈钢单轴常温与高温应力循环棘轮实验，提出了棘轮应力棘轮门槛值的概念，发展了一套基于棘轮应力一元参量的，描述高温棘轮循环饱和材料的单轴棘轮本构行为和常温演化行为的方法体系，新体系降低了传统二元应力控制棘轮变形认识带来的难度，由于新体系方程结构简洁，建模方法简便，描述实验结果精度高，故适合工程应用。

METHODOLOGICAL SYSTEM TO DESCRIBE UNIAXIAL RATCHETTING BEHAVIOR OF STAINLESS STEEL BY UNITARY PARAMETER

Based on a series of uniaxial ratchetting tests carried out for 304 and 1Cr18Ni9Ti stainless steels under cyclic stressing at room temperature and elevated temperature, the concepts of ratchetting stress and ratchetting stress threshold were presented and a set of methodological system was developed ,which can be used not only to model evoluted law of ratchetting strain of the materials under uniaxial stress at room temperature but also to simulate saturated ratchetting constitutive behavior of the materials at elevated temperatures. The presented system can overcome difficult problems to describe ratchetting deformation from traditional dualistic stress control. The ratchetting constitutive model and ratchetting evoluted model given in this paper have better precision to regress experimental data and are accessible to engineering application due to better concision and easy establishment in equation.