环保型淬火工艺对厚壁L80-13Cr钢管组织和性能的影响

Effect of environmentally friendly quenching process on microstructure and properties for thick-wall L80-13Cr steel pipe

对厚壁L80-13Cr无缝钢管进行1000℃保温150 min奥氏体化处理,分别采用风冷工艺、浸入水冷工艺和水雾冷却工艺进行冷却,然后在710℃下保温200 min进行回火。采用显微组织观察和力学性能测试等手段研究了3种淬火介质对厚壁L80-13Cr无缝钢管显微组织和力学性能的影响。结果表明:3种淬火介质的冷却性能由高到低分别是浸入水冷工艺、水雾冷却、风冷工艺;强度和冲击吸收能量都随着冷却速度的加快而提高,风冷工艺淬火的冲击吸收能量平均值为23.67 J,抗拉强度为764 MPa,水雾冷却工艺淬火的冲击吸收能量平均值为42.00 J,抗拉强度为787 MPa;浸入水冷工艺淬火的冲击吸收能量平均值为50.33 J,抗拉强度为800 MPa。但是浸入水冷工艺淬火容易有淬火裂纹,导致材料报废;雾化冷却工艺淬火,组织细小均匀,性能优异,是最合适的淬火冷却方式。

A thick-wall L80-13 Cr seamless steel pipe was austenitized at 1000℃ for 150 min,and then cooled by air,water immersion and water spray respectively,followed by tempering at 710℃ for 200 min.The effects of the quenching media on the microstructure and mechanical properties of the steel pipe were studied by means of microstructure observation and mechanical property testing.The results show that the cooling performance of the three quenching media from high to low are water immersion cooling process,water spray cooling process,and air cooling process;the strength and impact absorbed energy are increased with the acceleration of cooling rate.After quenching of the steel pipe,the average impact absorbed energy and the tensile strength under air cooling are 23.67 J and 764 MPa respectively,that under water spray cooling are 42.00 J and 787 MPa respectively,and that under water immersion cooling are 50.33 J and 800 MPa respectively.However,the process of water immersion cooling is prone to quenching cracking and resulting in the scrapping of the material.The water spray cooling produces fine and uniform microstructure and excellent performance,so it is the most suitable quenching cooling method.