镍基高温合金GH202高温氧化后的微观组织演变  

Microstructure Evolution of Nickel-based Superalloy GHGH202 After High Temperature Oxidation from 800℃to 1100℃

作　　者：曹将栋 姜伯晨 曹雪玉 夏雨乐 黄健 姚达 Cao Jiangdong;Jiang Bochen;Cao Xueyu;Xia Yuyue;Huang Jian;Yao Da(School of Intelligent Manufacturing and Information,Jiangsu Shipping College,Nantong 226010,China;Jiangsu Tenesun Co.,Ltd,Nantong 226010,China)

机构地区：[1]江苏航运职业技术学院智能制造与信息学院,江苏南通226010 [2]江苏天舒电器有限公司,江苏南通226010

出　　处：《稀有金属材料与工程》2021年第12期4288-4295,共8页Rare Metal Materials and Engineering

基　　金：Natural Science Foundation of Jiangsu Province(BK20191204);Natural Science Foundation of Jiangsu Province for Universities and Colleges(19KJB430031)。

摘　　要：研究了镍基高温合金GH202在800~1100℃高温氧化后晶粒、碳化物和强化相的演变过程。采用透射电子显微镜、扫描电子显微镜和电子背散射衍射对其微观结构进行了表征。结果表明:镍基高温合金的硬度随氧化温度的升高而降低,1100℃氧化100 h后,硬度降低了43.5%。800和900℃氧化后晶粒生长速度较慢,而经900℃氧化后晶界碳化物析出显著增加。在1000和1100℃氧化后,晶粒尺寸明显增大。氧化过程中晶界迁移是由晶界两侧自由能差决定,温度越高,晶界向曲率中心迁移越快,大量细小晶粒被吞并形成了大晶粒。大块状碳化物(MC)分解成大量的碳原子,与Cr原子结合形成少量的富Cr颗粒状M_(23)C_(6)。在900℃氧化150 h后,M_(23)C_(6)演化为富Ti的M_(23)C_(6)。随着氧化温度的升高,碳化物在γ相中回熔。在800、900和1000℃氧化后,γ′相逐渐长大,在1100℃氧化100 h后,完全溶解于γ相。Microstructure evolution of Ni-based superalloy GH202 after oxidation from 800℃to 1100℃was investigated.The results show that the hardness of GH202 decreases with the increase of oxidation temperature,and the hardness is decreased by 43.5%after oxidation at 1100℃for 100 h.The growth rate of the grains after oxidation at 800 and 900°C is slower and the grains increase slightly at 900℃.The grain size increases significantly after oxidation at 1000 and 1100℃,and many fine grains are annexed to form large grains due to grain boundary migration and elemental diffusion during the recrystallization at high temperatures for above100 h.The big block carbides(MC)decompose into a large number of carbon atoms which combine with Cr atoms to form a few Crrich granular M_(23)C_(6).After oxidation at 900°C for 150 h,the M_(23)C_(6)evolves into Ti-rich M_(23)C_(6).With the increase of oxidation temperature,the carbides almost melt intoγphase.Moreover,theγ’phase gradually grows up after oxidation at 800,900 and 1000℃,and it is completely dissolved into theγphase after oxidation at 1100℃for 100 h.

关 键 词：高温合金 微观组织结构 高温氧化 碳化物 强化相 

分 类 号：TG132.3[一般工业技术—材料科学与工程]