GH2132铁基高温合金表面等离子渗氮层的热稳定性  

Thermal Stability of Plasma-Nitrided Layer on Surface of GH2132 Fe-Based Superalloy

作　　者：宋伟秀 许晓磊[1] 于志伟[1] SONG Weixiu;XU Xiaolei;YU Zhiwei(Department of Materials Science and Engineering,Dalian Maritime University,Dalian 116026,China)

机构地区：[1]大连海事大学材料科学与工程系,大连116026

出　　处：《机械工程材料》2018年第9期16-20,共5页Materials For Mechanical Engineering

摘　　要：在723K下对GH2132铁基高温合金表面进行低温等离子体渗氮,并进行了不同温度(673,873,973K)保温5h处理,研究了保温处理前后渗氮层的截面形貌、物相组成、硬度和耐腐蚀性能。结果表明:GH2132铁基高温合金表面的渗氮层主要由氮在奥氏体中的过饱和固溶体,即膨胀奥氏体γN相组成;随加热温度的升高,渗氮层的厚度增加;当加热温度为673K时,γN相未发生分解,当加热温度为873,973K时,γN相分解生成晶格膨胀程度较低的γN相和CrN相;γN相的晶格膨胀率随着加热温度的升高而降低;随加热温度的升高,渗氮层的硬度先增大后降低,并在加热温度为873K时达到最大,约为926HV;不同温度保温5h后渗氮层的耐腐蚀性均降低。Low temperature plasma nitriding was conducted on the surface of GH2132 Fe-based superalloy at723 K,and then the nitrided tested alloy was treated at different temperatures（673,873,973 K）for 5 h.The sectional morphology,phase composition,hardness and corrosion resistance of the nitrided layer before and after treatment were analyzed.The results show that the nitrided layer on the surface of GH2132 Fe-based superalloy was mainly composed of supersaturated solid solution of nitrogen in austenite,namely expanded austeniteγNphase.The thickness of nitrided layer increased with increasing heating temperature.TheγN phase was undecomposed during heating at 673 K.During heating at 873,973 K,theγN phase was decomposed toγNphase with lower lattice expansion and CrN phase.The lattice expansion rate ofγNphase decreased with the increase of heating temperature.The hardness of nitrided layer was firstly increased then decreased with increasing heating temperature,and reached to the largest of 926 HV during heating at 873 K.The corrosion resistance of nitrided layer after heating at different temperatures for 5 hall decreased.

关 键 词：铁基高温合金 膨胀奥氏体 热稳定性 渗氮层 

分 类 号：TG156.82[金属学及工艺—热处理]