预热处理工艺对13Cr马氏体不锈钢无缝钢管调质后组织和力学性能的影响

Effects of Preheat Treatment on Microstructure and Mechanical Properties of 13Cr Martensite Stainless Steel Seamless Tube after Quenching and Tempering

分别采用等温退火和去应力退火两种工艺对13Cr马氏体不锈钢无缝钢管进行预热处理试验,再经980℃淬火油冷和720℃回火空冷,对比组织和性能。结果表明,等温退火相对于去应力退火的预热处理工艺,调质后有一定改善:材料的-10℃纵向冲击功提高31%,0℃横向冲击功提高21%,冲击功离散度由26 J减小到9 J;实际晶粒度由8～4级提高到9～8级;硬度不均匀性由3.2 HRC缩小到1.5 HRC。该等温退火预热处理工艺成功用于生产实践,性能一次检验合格率由原先的60%提高到100%。

13Cr martensitic stainless steel seamless steel tubes were pretreated by isothermal annealing and stress relief annealing respectively. The microstructure and properties were compared after quenching at 980℃ with oil cooling and tempering at 720 ℃ the air cooling. The results show that, the isothermal annealing and tempering has some improvement compared with the pre-heat treatment process of stress removal annealing. The longitudinal impact energy at -10 ℃ increases by 31% and the transverse impact energy at 0℃ increases by 21%, and the impact energy dispersion decreases from 26 % to 9%. The actual grain size is increased from 8-4 grade to 9-8 grade, and the hardness inhomogeneity is reduced from 3.2 HRC to 1.5 HRC. The isothermal annealing preheat treatment process has been successfully used in production practice, and the pass rate of one time inspection of properties has been increased from 60 % to 100 %.