高压断路器触指C18150合金抗应力松弛行为研究

Stress Relaxation Behavior of Contact Finger C18150 Alloy for Typical High Voltage Circuit Breaker

采用应力松弛试验研究了60~300℃条件下C18150合金的应力松弛行为,通过二次延迟函数模型对应力松弛曲线进行拟合,分析C18150合金的塑性应变速率随应力的变化情况。结果表明,在应力松弛过程中,C18150合金存在减速动态松弛和恒速稳态松弛两个阶段。在减速动态松弛过程中松弛率较大,而恒速稳态松弛过程中松弛率逐渐为0,剩余应力逐渐逼近应力松弛极限。随着温度逐渐升高,应力松弛极限逐步减小,残余应力衰减率逐渐增加,且在100℃以内,残余应力衰减率小于10%。C18150合金的应力松弛机制为第二相颗粒增强。

The stress relaxation behavior of C18150 alloy at 60~300℃was investigated by stress relaxation test.The stress relaxation curve was fitted by quadratic delay function model,and variation of plastic strain rate with stress of C18150 alloy was analyzed.The results indicate that the stress relaxation process of C18150 alloy can be divided into two stages,which are deceleration dynamic relaxation and constant-speed steady-state relaxation.During the deceleration dynamic relaxation process,the relaxation rate is larger,which is gradually to zero during the constant-speed steady-state relaxation process,and the residual stress is infinitely close to the stress relaxation limit.With the increase of temperature,the stress relaxation limit is gradually decreased and the residual stress decay rate is gradually increased,which is less than 10%within 100℃.The stress relaxation mechanism of C18150 alloy is characterized by second phase particle reinforcement.