摘要
采用DIL 805A型全自动相变仪测定LC3低温用铸钢在0.05~150℃/s不同冷却速度下的膨胀曲线,采用切线法测定相变点Ac_(1)为700℃,Ac_(3)为849℃;结合显微组织分析和显微硬度确定实际转变产物,利用Origin软件绘制CCT曲线图。结果表明,冷却速度在0.05~2℃/s时,组织为铁素体+珠光体;在5~20℃/s时,组织为铁素体+珠光体+贝氏体;在30~50℃/s时,组织为贝氏体+马氏体;在80℃/s时,组织为马氏体+残留奥氏体;在100~150℃/s时,组织为全马氏体。随着冷却速度的增大,LC3低温用铸钢硬度逐渐提高,硬度由168 HV10增大至453 HV10。马氏体临界冷却速度在80℃/s左右。
DIL 805A type fully automatic phase transformer was used to determine the expansion curve of LC3 cryogenic cast steel under different cooling rates between 0.05-150 ℃/s, and the tangent method was used to determine the phase transformation point Ac_(1) of 700 ℃ and Ac_(3) of 849 ℃. Combined with microstructure analysis and microhardness to determine the actual transformation products, and the CCT curve was plotted using Origin software. The results show that the microstructure is ferrite + pearlite when the cooling rate is 0.05-2 ℃/s, ferrite + pearlite +bainite when it is 5-20 ℃/s, bainite + martensite when it is 30-50 ℃/s, martensite + retained austenite when it is 80 ℃/s, and martensite when it is 100-150 ℃/s. Hardness of the LC3 cryogenic cast steel gradually increases from 168 HV10 to 453 HV10 with the increasing of cooling rate. Martensite critical cooling rate is about 80 ℃/s.
作者
陈坤
宫文国
常雪婷
尹衍升
Chen Kun;Gong Wenguo;Chang Xueting;Yin Yansheng(College of Ocean Science and Engineering,Shanghai Maritime University,Shanghai 201306,China;Shandong Yanshan Precision Machinery Co.,Ltd.,Jinan Shandong 271100,China)
出处
《金属热处理》
CAS
CSCD
北大核心
2024年第12期137-141,共5页
Heat Treatment of Metals
基金
国家重点研发计划(2022YFB3705303)
上海市科委技术标准项目(21DZ2205700)
上海深海材料工程技术中心项目(19DZ2253100)。
