【摘要】 为了探究低碳铬钼镍轴承钢在不同热处理工艺下组织和韧性的变化规律,对其进行奥氏体等温保温实验,研究了加热温度、保温时间对低碳铬钼镍轴承钢奥氏体晶粒尺寸、碳化物和冲击功的影响。结果表明:奥氏体化温度≤1 070℃时,钢中碳化物溶解不明显,碳化物面积占比为1.93%,奥氏体晶粒长大不明显,平均晶粒尺寸为49μm,冲击功>50 J;奥氏体化温度≥1 080℃时,碳化物面积占比为1.23%,1 090℃时碳化物面积占比为0.16%,碳化物大量溶解,产生解钉效应,奥氏体晶粒明显长大,冲击功大幅下降,低于30 J;保温时间大于45 min时,晶粒尺寸趋于稳定。根据实验结果得出试验钢在1 050～1 090℃加热并保温15～60 min的晶粒长大模型,可为该钢种热处理工艺的设计提供理论依据。更多还原

【Abstract】 In order to investigate the microstructure and toughness of low carbon chromium molybdenum nickel bearing steel under different heat treatment processes, an austenitic isothermal insulation test is performed. The effects of heating temperature and holding time on the austenite grain size, carbides and impact energy of low-carbon chromium-molybdenum-nickel bearing steel are studied. The results show that when the austenitizing temperature is not higher than 1 070 ℃, the carbides in the steel do not dissolve significantly, the area percentage of carbides is 1.93%, the austenite grain growth is not obvious, the average grain size is 49 μm, and the impact energy absorption is greater than 50 J. When the austenitizing temperature is 1 080 ℃ or higher, the carbide area percentage is 1.23%, while the carbide area percentage is 0.16% at 1 090 ℃, and the carbides dissolve in large quantities, resulting in a nailing effect and bigger austenite grains, and the impact energy absorption drops sharply to less than 30 J. When the holding time is longer than 45 min, the grain size tends to be stable. According to the test results, a grain growth model of the test steel heated at 1 050～1 090 ℃ for 15～60 min is provided, which can provide theoretical basis for the design of the heat treatment process for the steel.更多还原