摘要
针对四代核电钠冷快堆循环水泵大口径超级双相不锈钢阀体铸件制造中出现的开裂、缩松、缩孔和冷隔等问题,开展了第二相析出、铸造工艺和固溶冷速模拟工艺探索,以研究其对铸件组织、性能和成形的影响。结果表明,铸件冷却至1000℃左右打箱空冷,析出第二相较少,随着打箱温度降低,第二相析出比例逐渐增加;对铸件进行型线流畅设计、浇注系统和补缩系统等方面合理设计,并经铸件凝固过程数值模拟,预测铸造工艺实施结果良好;当固溶冷却速率大于0.4℃/s时,可有效避免铸件组织中第二相的析出。根据工艺研究结果来生产阀体,铸件固溶热处理后组织中α相和γ相比例接近1∶1,关键部位射线探伤满足技术标准要求,铸件力学性能和耐腐蚀性能优异,可较好满足海水氯化物腐蚀介质工况要求。
Aiming at the problems of the cracks,the shrinkage,the dispersed shrinkage,the cold shut,and so on in the manufacturing process of large diameter super duplex stainless steel valve body casting for circulating water pump of the fourth generation nuclear power sodium cooled fast reactor,the simulation experiments of second phase precipitation,casting process and solid solution cooling rate were carried out to study the effects on the microstructures,the properties and the forming of the casting.The results show that when the casting is cooled to about 1000℃,the second phase precipitates less,and the proportion of the second phase precipitates gradually increases with the decrease of the pumping temperature.The casting pattern line fluency design,the gating and feeding systems design,and other reasonable designs had been finished,and the prediction result was well through numerical simulation of solidification process of the casting.When the solution cooling rate is more than 0.4℃/s,the precipitation of the secondary phase can be effectively avoided.Based on above the results,the valve body was manufactured.After solution heat treatment,the ratio ofαphase toγphase in the structure of the casting is close to 1∶1,and the radiographic flaw detection of key parts meets the technical standard specifications.The mechanical and corrosion resistant properties of the casting are excellent,meeting the working condition requirements of the seawater chloride corrosive medium.
作者
王行
王爱琴
李昌义
禹兴胜
谢敬佩
贾冠飞
魏加赞
胡中华
WANG Hang;WANG Ai-qin;LI Chang-yi;YU Xing-sheng;XIE Jing-pei;JIA Guan-fei;WEI Jia-zan;HU Zhong-hua(School of Materials Science and Engineering,Henan University of Science and Technology,Luoyang 471023,Henan,China;Luoyang CITIC HIC Casting&Forging Co.,Ltd.,Luoyang 471039,Henan,China;CITIC Heavy Industries Co.,Ltd.,Luoyang 471039,Henan,China)
出处
《铸造》
CAS
北大核心
2022年第12期1485-1489,共5页
Foundry
基金
洛阳市重大科技专项(2021005A)。
关键词
超级双相不锈钢
阀体
显微组织
铸造工艺模拟
super duplex stainless steel
valve body
microstructure
casting process simulation
