Haynes230镍基合金拉伸DSA效应和循环硬化特性研究

Study on DSA effect in tensile process and cyclic hardeningcharacteristics for Haynes230 nickle-base alloy

基于Haynes230镍基合金760℃下的拉伸和疲劳实验结果,讨论了拉伸过程中的动态应变时效(DSA)效应以及不同应变幅值下的循环硬化特性,采用ABAQUS有限元软件对拉伸和疲劳特性进行了模拟。实验结果表明,Haynes230镍基合金在760℃拉伸过程中表现出明显的DSA效应,最大应力跌幅为3.8 MPa。在单轴疲劳过程中,材料表现出明显的循环硬化现象。采用ABAQUS有限元软件和基于热激活位错运动的指数流动准则对拉伸过程中的DSA效应进行了模拟。模拟结果与实验结果吻合很好,整个拉伸过程最大应力误差仅为3.9%,最大应力跌幅为9.3 MPa。选择Chaboche混合模型进行了应变范围0.6%和0.8%下的循环硬化模拟计算,模拟得到的前100周次内峰值应力的平均误差分别为4.3%和3.4%。

The dynamic strain aging(DSA)effect during tensile process and the cyclic hardening characteristics with different strain amplitudes were discussed based on the tensile and fatigue experimental results for Haynes230 nickel-base alloy at 760℃,and the tensile and fatigue characteristics were simulated by ABAQUS finite element software.The experimental results show that Haynes230 nickel-base alloy exhibits obvious DSA effect at 760℃,and the maximum stress drop is 3.8 MPa.The material exhibits obvious cyclic hardening phenomenon during uniaxial fatigue process.The ABAQUS finite element software and exponential flow criterion based on thermal activated dislocation motion were used to simulate the DSA effect during tensile process.The simulation results are in good agreement with the experimental results,and the maximum stress error is only 3.9%during whole tensile process,and the maximum stress drop is 9.3 MPa.The Chaboche mixed model was used to simulate and calculate the cyclic hardening with strain range of 0.6%and 0.8%.The average error of peak stress in the first 100 cycles is 4.3%and 3.4%,respectively.