回火温度对CREG-1钢组织和力学性能的影响

Effect of tempering temperature on microstructure and mechanical properties of CREG-1 steel

在不同温度下对CREG-1钢进行回火处理,对其力学性能进行测试,并用扫描电镜和金相显微镜对冲击缺口及金相组织进行观察,分析了回火温度对其力学性能和组织的影响。结果表明：随着回火温度的升高,其冲击韧性明显升高,硬度逐渐下降,组织中析出的细小碳化物增多;回火温度高于560℃时,碳化物颗粒聚集长大,硬度显著降低,冲击断裂形式由准解理断裂转变为韧性断裂。CREG-1钢在540～560℃范围内回火具有均衡的力学性能。

Mechanical properties of CREG-1 steel was measured after tempering at different temperatures,the impact fracture morphologies and microstructures of CREG-1 steel were observed by means of OM and SEM,and the influence of tempering temperatures on its microstructure and mechanical properties was analyzed.The results show that with the increase of tempering temperature,the impact toughness and the quantity of small carbides of CREG-1 steel increases,but its hardness decreases slowly.When the tempering temperature is higher than 560 ℃,the dimension of carbides increases and the hardness of CREG-1 steel decreases significantly,and its rupture mechanism changes from quasi-cleavage fracture to ductility fracture.The CREG-1 steel has good mechanical property when tempered at 540-560℃.