金属快速加热的非弹性热软化研究

INELASTIC THERMO-SOFTENING OF METALS UNDER RAPID HEATING

本文利用电阻加热法研究了Ｈ６２黄铜和ＬＹ１２铝合金在短时热冲击下的非弹性热软化性能．发现了两种合金的屈服温度随加热速率提高而明显提高的现象以及其在不同加热速率下的再结晶特点．将Ｊｏｈｎｓｏｎ－Ｍｅｈｌ恒温条件下的再结晶动力方程推广到变温的情况，从理论分析了加热速率高低对金属再结晶过程的影响，并提出了屈服温度上下限的概念．

Study was made of the experimental and theoretical analyses for inelastic thermo-softening of H62 copper and LY12 aluminum specimens subjected to rapid resistance heating by a large electric current and under constant uniaxial tensile load. It is found that the yield temperature of the specimens increases markedly with heating rates. The effects caused by mechanical and metallurgical properties under rapid heating of metals are also investigated. An extended Johnson-Mehl equation of recrystallization is derived to include the effects of heating rates. A new concept of upper and lower limits of yield temperature is put forward for a metal under various heating rates.