Mo/Nb/Ta/Ti微合金化310S不锈钢在700℃的第二相析出  

Second-phase Precipitation in Mo/Nb/Ta/Ti Minor-alloyed 310S Stainless Steel at 700℃

作　　者：吕阳[1] 温冬辉 王镇华 王清[1] 唐睿[2] 何欢 LV Yang;WEN Donghui;WANG Zhenhua;WANG Qing;TANG Rui;HE Huan(Key Laboratory of Materials Modification by Laser, Ion and Electron Beams （Ministry of Education）, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024, China;Science and Technology on Reactor Fuel and Materials Laboratory, Nuclear Power Institute of China, Chengdu 610213, China;Guangxi Key Laboratory of Processing for Non-Ferrous Metal and Featured Materials, Nanning 530004, China)

机构地区：[1]大连理工大学三束材料改性教育部重点实验室材料科学与工程学院,大连116024 [2]中国核动力研究设计院反应堆燃料及材料重点实验室,成都610213 [3]广西有色金属及特色材料加工重点实验室,南宁530004

出　　处：《材料研究学报》2018年第5期371-380,共10页Chinese Journal of Materials Research

基　　金：资助项目国际科技合作计划(2015DFR60370);中央高校基本科研业务费专项资金(DUT16ZD212);国际热核聚变实验堆计划(2015GB121004);国家重点研发计划(2017YFB0702400和2017YFB0306100);广西有色金属及特色材料加工重点实验室开放基金(GXKFJ16-11)~~

摘　　要：高Cr/Ni奥氏体不锈钢在高温下的组织稳定性及第二相析出直接影响合金的力学性能,本文以低碳310S奥氏体不锈钢(Fe-25Cr-22Ni-0.046C,%,质量分数)为基础合金,通过添加多种微量合金化元素(Mo,Nb,Ta,Ti)来研究其对合金第二相析出的影响。采用真空电弧炉熔炼合金锭样品,并在1150℃进行多道次热轧,然后进行1150℃/0.5 h固溶处理(水冷),900℃/0.5 h稳定化处理并随炉冷却,最后在700℃下进行25~408 h时效处理。对不同状态下的样品进行XRD结构分析、金相(OM)、扫描电镜(SEM)和透射电镜(TEM)组织表征以及力学性能测试。实验结果表明,Mo/Nb/Ta/Ti共同微合金化虽然提高了合金的强度,但会使得脆性s相出现在初期的稳定化阶段,并且在随后的时效过程中,随时效时间延长,s相含量增加,但是已经析出的Cr_(23)C_6也会逐步溶解,从而恶化了合金高温下的力学性能。微量合金化会影响310S合金高温下的第二相析出行为,而影响其组织稳定性。The microstructural stability and second-phase precipitation of austenitic stainless steels（ASSs） with high Cr and Ni contents at high temperatures affect their mechanical property directly. The effect of minor-addition of Mo, Nb, Ta, and Ti on the second-phase precipitation in a low-carbon 310 S stainless steel（Fe-25 Cr-22 Ni-0.046 C, %, mass fraction） has been investigated in the present work. Alloy ingots were prepared by vacuum arc melting, and hot rolled at 1150℃ for multiple passes into sheets. The sheet samples were then heat-treated in sequence： solid-solution at 1150℃ for 0.5 h followed by water cooling, stabilization at 900℃ for 0.5 h followed by furnace cooling, and aging treatment at 700℃ for different times（25~408 h）. The steels were characterized by means of XRD, OM, SEM and TEM. Their mechanical property were examined after different treatments. Experimental results show that the co-addition of minor Mo/Nb/Ta/Ti improves the strength of the steels. However, the brittle s-phase began to appear at the early stage of stabilization process in the Mo/Nb/Ta/Ti-modified steel, while it was not existed in the master steel 310 S. During the aging process, the content of s-phase particles increases with the increase of aging time, and the coarse Cr23 C6 particles will be dissolved finally, which will deteriorate the mechanical property of the steels. Both the types and amounts of minor-alloying elements affect the secondphase precipitation, and then the microstructural stability.

关 键 词：金属材料 奥氏体不锈钢 310S合金 微合金化 相析出 组织稳定性 

分 类 号：TG142.25[一般工业技术—材料科学与工程]