Microstructural Characteristics and Mechanical Properties of Low-Alloy, Medium-Carbon Steels After Multiple Tempering
Microstructural Characteristics and Mechanical Properties of Low-Alloy, Medium-Carbon Steels After Multiple Tempering
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DOI：
10.1007/s40195-018-0805-6
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发表时间：
2019-01-01
影响因子：
3.5
通讯作者：
Owens, Dave
中科院分区：
文献类型：
--
作者：
Abbasi, Erfan;Luo, Quanshun;Owens, Dave
研究了NiCrMoV和nicrsi合金中碳钢经多次回火后的组织和力学性能。在奥氏体化后，钢通过油淬硬化，随后在250至500摄氏度的温度下进行二次或三次回火。样品使用扫描电子显微镜和x射线衍射进行表征，同时通过维氏硬度测试，v形缺口夏比冲击测试和拉伸测试评估机械性能。结果表明，残余奥氏体在400℃时保持稳定，低于400℃的多次回火均不能使残余奥氏体完全分解。与回火次数无关，组织、硬度和冲击韧性主要随回火温度的变化而变化。此外，NiCrMoV钢在不同温度下单次/三次回火后的冲击韧性相当相似，而NiCrSi钢在400℃下单次/两次回火后表现出回火马氏体脆化，这种差异主要是由于合金添加对析出行为的影响。
The microstructure and mechanical properties of NiCrMoV- and NiCrSi-alloyed medium-carbon steels were investigated after multiple tempering. After austenitising, the steels were hardened by oil quenching and subsequently double or triple tempered at temperatures from 250 to 500 degrees C. The samples were characterised using scanning electron microscopy and X-ray diffraction, while the mechanical properties were evaluated by Vickers hardness testing, V-notched Charpy impact testing and tensile testing. The results showed that the retained austenite was stable up to 400 degrees C and the applied multiple tempering below this temperature did not lead to a complete decomposition of retained austenite in both steels. It was also found that the microstructure, hardness and impact toughness varied mainly as a function of tempering temperature, regardless of the number of tempering stages. Moreover, the impact toughness of NiCrMoV steel was rather similar after single/triple tempering at different temperatures, while NiCrSi steel exhibited tempered martensite embrittlement after single/double tempering at 400 degrees C. The observed difference was mainly attributed to the effect of precipitation behaviour due to the effect of alloying additions in the studied steels.