汽轮机用Cr-Mo-V耐热钢的热处理

Heat Treatment of Cr-Mo-V Heat Resistant Steel for Steam Turbine

采用力学性能测试和显微组织分析等手段,研究了1.5Cr-1Mo-0.25V钢在正火+回火态和调质态下的显微组织和力学性能的差异。结果表明,1.5Cr-1Mo-0.25V钢在一次正火+回火的基础上再增加一道正火,可以在一定程度上改善其冲击韧性;而采用940℃正火+730℃回火的调质热处理工艺,可以得到细小均匀的回火态铁素体和短条状贝氏体组织,从而保证了阻碍裂纹扩展的能力,使得钢的冲击吸收能量达到130 J以上。

The differences of microstructure and mechanical properties of 1. 5 Cr-1 Mo-0. 25 V steel under normalized and tempered state and quenched and tempered state were studied by means of mechanical property test and microstructure analysis. The results showed that the addition of once normalizing on the basis of once normalizing and tempering of 1. 5 Cr-1 Mo-0. 25 V steel could also improve the impact toughness of the material to a certain extent. While under quenching（ 940 ℃）and tempering（ 730 ℃） heat treatment process,the fine and uniform microstructure of tempered ferrite and short striated bainite could be obtained,which prevented the crack expansion,thus the impact absorption energy of steel could be up to over than 130 J.