氮碳共渗及渗氮处理时2205双相不锈钢的组织转变  

Microstructure transformation of 2205 duplex stainless steel during nitrocarburizing and nitriding treatment

作　　者：赵卫民 唐静 李小双 夏琪良 王文臣 李丹 ZHAO Wei-min;TANG Jing;LI Xiao-shuang;XIA Qi-liang;WANG Wen-chen;LI Dan(School of Materials Science and Engineering,China University of Petroleum(East China),Qingdao 266580,China;Qingdao Fengdong Heat Treatment Co Ltd,Qingdao 266108,China)

机构地区：[1]中国石油大学(华东)材料科学与工程学院,山东青岛266580 [2]青岛丰东热处理有限公司,山东青岛266108

出　　处：《材料热处理学报》2023年第2期148-155,共8页Transactions of Materials and Heat Treatment

摘　　要：利用光学显微镜、X射线衍射、电子探针和扫描电镜等研究了2205双相不锈钢经420℃和380℃气体渗氮和氮碳共渗处理后的组织。结果表明:渗氮和氮碳共渗都可使2205双相不锈钢表层的奥氏体(γ)和铁素体(α)转变为膨胀奥氏体相(γ_(N)),且相变层厚度随处理温度的升高而增大,但420℃处理时γ_(N)相会受热分解析出新相CrN。相同处理温度下,γ相比α相的相变层厚度大,且渗氮时的这种差异较氮碳共渗更为明显。γ相和α相向γ_(N)相转变过程的差异以及渗碳和温度对氮扩散的影响共同导致了不同工艺处理的相变层的显著差异。Microstructure of 2205 duplex stainless steel after gas nitriding and nitrocarburizing at 420℃ and 380℃ was studied by means of optical microscope,X-ray diffraction,electron probe and scanning electron microscopy.The results show that the austenite(γ)and ferrite(α)in the 2205 duplex stainless steel surface are transformed to expanded austenite(γ_(N))after nitriding and nitrocarburizing treatment,and the thickness of the phase-transition layer increases with the increase of the treatment temperature,but at 420℃ γ_(N)phase will decompose and precipitate new phase CrN.At the same treatment temperature,the thickness of phase-transition layer inγphase is thicker than that inαphase,and this difference is more obvious in nitriding than in nitrocarburizing.The difference in the transformation process fromγphase andαphase to γ_(N)phase,and the influence of carburizing and temperature on nitrogen diffusion,together lead to significant differences in the phase-transition layers treated by different processes.

关 键 词：双相不锈钢 渗氮 氮碳共渗 相变 

分 类 号：TG174.44[金属学及工艺—金属表面处理]