新型二次硬化钢25CrMo3NiTiVNbZr的高温力学性能和强化机理  

High-temperature Mechanical Properties and Strengthening Mechanism of New Secondary Hardened Steel 25CrMo3NiTiVNbZr

作　　者：李若浩 胡霄雨 王中成 李浩 杨勇 徐乐[1] 梁恩溥 何肖飞[1] LI Ruohao;HU Xiaoyu;WANG Zhongcheng;LI Hao;YANG Yong;XU Le;LIANG Enpu;HE Xiaofei(Research Institite of Special Steels,Central Iron and Steel Research Institute Co.,Ltd.,Beijing 100081,China;The Chinese Society for Metals,Beijing 100010,China;Inner Mongolia North Heavy Industries Group,Baotou 014010,China;Chongqing Changan Wangjiang Industry Group Co.,Ltd.,Chongqing 400020,China)

机构地区：[1]钢铁研究总院有限公司特殊钢研究院,北京100081 [2]中国金属学会,北京100010 [3]内蒙古北方重工业集团有限公司,包头014010 [4]重庆长安望江工业集团有限公司,重庆400020

出　　处：《材料研究学报》2024年第5期390-400,共11页Chinese Journal of Materials Research

基　　金：农机装备材料生产应用示范平台(TC200H01X/05)。

摘　　要：使用JMatpro和Thermo-Calc软件优化25Cr3Mo3NiNbZr钢的成分,使用透射电镜(TEM)、电子背散射衍射(EBSD)和相分析等手段表征在700℃高温拉伸前后试样的显微组织和析出相以研究其高温强化机理。结果表明:25CrMo3NiTiVNbZr钢700℃的高温抗拉强度和屈服强度分别为543 MPa、409 MPa,比25Cr3Mo3NiNbZr钢提高了139 MPa和123 MPa。根据对这种钢高温强化机理的分析,析出强化是主要强化方式。在700℃高温拉伸25CrMo3NiTiVNbZr钢其析出强化增量为367 MPa,比25Cr3Mo3NiNbZr钢提高147 MPa,其主要原因是在25CrMo3NiTiVNbZr中析出了热稳定性更高、尺寸更小(平均尺寸为7.93 nm)的析出相。A novel secondary hardened steel 25CrMo3NiTiVNbZr was developed via optimization the chemical composition of the 25Cr3Mo3NiNbZr steel bymeans of the so called JMatpro and Thermo-Calc software.Then the microstructure,phase composition,morphology of precipitates and mechanical performance at 700℃of the 25CrMo3NiTiVNbZr steel were characterized by means of transmission elec-tron microscopy(TEM),electron backscattering diffraction(EBSD),while its the high-temperature streng-thening mechanism was also elucidated.The results show that the tensile strength and yield strength of 25CrMo3NiTiVNbZr steel at 700oC are 543 MPa and 409 MPa,respectively,which are 139 MPa and 123 MPa higher than that of 25Cr3Mo3NiNbZr steel.The high-temperature strengthening of the 25CrMo3NiTiVNbZr steel may mainly ascribed to themechanism,precipitation strengthening.In the pro-cess of being stretched at 700oC,the precipitation strengthening increment derived from the precipitation of the strengthening phase for the 25CrMo3NiTiVNbZr steel reached 367 MPa,which was 147 MPa high-er than that of the 25Cr3Mo3NiNbZr steel.This is mainly due to the higher thermal stability and smaller size(average size at 7.93 nm)of the precipitated strengthening phases in the 25CrMo3NiTiVNbZr steel.After high-temperature stretching,the average size of precipitates remained at 8.14 nm.

关 键 词：金属材料 高温强度 成分优化 强化机理 纳米析出相 

分 类 号：TG142[一般工业技术—材料科学与工程]