摘要
The critical points and time-temperature-transformation(TTT)curves of the isothermal transformation diagrams for a high-speed steel casting on a horizontal centrifugal casting machine had been determined experimentally in the study.The effects of quenching temperature on the microstructures and properties of centrifugal casting high speed steel(HSS)roll has been investigated using scanning electron microscopy(SEM), light optical microscopy(LOM)and X-ray diffraction(XRD)as well as using tensile,impact,and hardness tests. The results show that the HSS roll has excellent hardenability and its matrix structure can be transformed into the martensite after being quenched in the sodium silicate solution.The retained austenite in the quenching structure increases and the hardness decreases when the quenching temperature exceeds 1,040℃.The tensile strength and impact toughness of HSS roll increase once the quenching temperature is raised from 980℃to 1,040℃. However,the tensile strength and impact toughness have no significant change when the quenching temperature exceeds 1,040℃.The HSS roll quenched at 1,040℃exhibits excellent comprehensive mechanical properties.
The critical points and time-temperature-transformation （TTT） curves of the isothermal transformation diagrams for a high-speed steel casting on a horizontal centrifugal casting machine had been determined experimentally in the study. The effects of quenching temperature on the microstructures and properties of centrifugal casting high speed steel （HSS） roll has been investigated using scanning electron microscopy （SEM）, light optical microscopy （LOM） and X-ray diffraction （XRD） as well as using tensile, impact, and hardness tests. The results show that the HSS roll has excellent hardenability and its matrix structure can be transformed into the martensite after being quenched in the sodium silicate solution. The retained austenite in the quenching structure increases and the hardness decreases when the quenching temperature exceeds 1,040℃. The tensile strength and impact toughness of HSS roll increase once the quenching temperature is raised from 980℃ to 1,040℃. However, the tensile strength and impact toughness have no significant change when the quenching temperature exceeds 1,040℃. The HSS roll quenched at 1,040℃ exhibits excellent comprehensive mechanical properties.
基金
supported by the innovation fund of small and medium-sized enterprise of Science&Technology Ministry of China under grant(07C26215110842).
关键词
高速钢轧辊
临界点
淬火温度
曲线图
扫描电子显微镜
high speed steel roll
quenching temperature
metallic matrix
mechanical property
