【作者】 韩利战； 顾剑锋； 龙智南； 徐骏； 潘健生；

【Author】 HAN Li-zhan~(1,3),GU Jian-feng~(1,3),LONG Zhi-nan~(2,3), XU Jun~1,PAN Jian-sheng~(1,3) (1.School of Materials Science and Engineering,Shanghai Jiaotong University, Shanghai Key Laboratory of Materials Laser Processing and Modification,Shanghai 200240,China; 2.Shanghai Heavy Machinery Plant Co.Ltd,Shanghai,200240; 3.PAN JIANGSHENG Academician Studio at Shanghai Electric Group,Shanghai,200240)

【机构】 上海交通大学材料科学与工程学院,上海市激光制造与材料改性重点实验室； 上海电气集团潘健生院士工作室； 上海重型机器厂有限公司；

【摘要】 本文在热模拟试验机Gleeble3500上采用膨胀法研究了核电锻件用钢SA508 Gr.3的过冷奥氏体连续转变冷却曲线,并用扫描电镜和光学显微镜观察不同冷却速度和不同等温温度下组织转变产物。SA508 Gr.3钢马氏体临界冷却速度大于20℃/s,贝氏体临界冷却速度1℃/s。在低于0.5℃/s冷速下出现粒状贝氏体和针状铁素体等不良组织。SA508 Gr.3钢属中等淬透性钢,对热处理的要求很高,而且很难在核电装备大锻件的整个截面上获得均匀一致的组织和性能。这些应在核电装备制造中引起高度重视并进一步开展深入研究。更多还原

【Abstract】 The continuous cooling transformation(CCT) diagram has been investigated for the SA508 Gr.3 steel used as the large forgings of nuclear power using the thermal simulator Gleeble3500,the microstructures obtained under different cooling rates and isothermal temperatures have also been observed carefully with the SEM and OM.The results show that the critical cooling rate of martensite is larger than 20℃/s,and that for bainite is about l℃/s.The bad microstructures such as the granular bainite,and acicular ferrite form when the cooling rate less than 0.5℃/s.The medium hardenability of steel SA508 Gr.3 proposes very high requirement for heat treatment,and it is very difficult to get uniform microstructure and property throughout the whole section of a large forging for nuclear power.Thus,highly attention should be paid on the manufacture of nuclear power equipments and corresponding fundamental research in this aspect should be carried out intensively.更多还原