加热速度和保温时间对X70钢组织与性能的影响

Effects of heating rate and holding time on microstructure and mechanical properties of X70 steel

用Gleeble-3500型热模拟试验机研究了加热速度和保温时间对X70钢组织和性能的影响。结果表明,加热速度对奥氏体相变点及冷却后的组织和性能有显著影响。随加热速度的增加,相变点呈线性增加,而钢的强度和韧性降低。随着保温时间的延长,钢的强度在保温时间为60 s时达到最大值,随保温时间的进一步增加,强度呈降低的趋势;而且随加热温度的升高,降低的趋势更明显。而冲击韧性则随保温时间的延长呈降低趋势。

The influences of heating rate and holding time on the microstructure and mechanical properties of X70 steel were studied by using Gleeble-3500 thermo mechanical simulator.The results show that the heating rate has great effect on phase transformation temperatures,microstructure and mechanical properties of the samples cooled to room temperature.With increasing the heating rates,the phase transformation temperature increases linearly,but the strength and impact toughness decrease.As the holding time increases,the strength of steel gets highest value when holding time is 60 s,while,further increasing the holding time,the strength decreases.Moreover,with the rise of heating temperature,the strength decreases significantly.However,the impact toughness decreases with increasing the holding time.