热处理GCr15钢M/B下复合组织的强韧性分析

Analysis on Strength and Toughness of Steel GCr15 M/B Composite Structure

GCr15钢经选定的热处理方案热处理后,获得了以马氏体、下贝氏体为主的复合组织,金相显微镜下马氏体为板条状,下贝氏体呈细长针状。结果表明:冲击韧度随下贝氏体含量的增加而上升,硬度随下贝氏体含量的增加而下降。下贝氏体含量随等温时间的延长而增加,当等温时间为30 min,马氏体含量为34.7%、下贝氏体的含量为31.3%左右时,钢的硬度≥59.9 HRC,冲击韧度≤78.1 J/cm2,钢的强韧匹配性效果最佳。

After heat treatment for the selected heat treatment on GCr15 steel, the lath=like martensite and slender needle bainite were obtained. The experimental results show that the impact toughness increases with the increase of lower bainite content, but hardness decreases. The content of lower bainite increases with the increase of isothermal time, when the isothermal time is 30 min, martensite content is 34.7%, bainite content is 31.3%, hardness≥ 60.1 HRC, impact toughness of steel is lower ≤98.8J/cm^2, best matching of strengthening and toughening of steel is obtained.