时效工艺对2205双相不锈钢σ相析出行为的影响  

Effect of aging process onσphase precipitation of 2205 duplex stainless steel

作　　者：高晓丹[1,2] 任学平 李晶琨[1] 闫强 袁傲明 Gao Xiaodan;Ren Xueping;Li Jingkun;Yan Qiang;Yuan Aoming(School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China;Institute for Advanced Materials and Technology,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]北京科技大学材料科学与工程学院,北京100083 [2]北京科技大学新材料技术研究院,北京100083

出　　处：《金属热处理》2020年第10期1-5,共5页Heat Treatment of Metals

摘　　要：通过光学显微镜、扫描电镜对2205双相不锈钢1050、1350℃固溶30 min+650~1000℃时效0.5~1440 min后σ相形貌和含量进行观测。结果表明:经过1050℃固溶处理后,2205双相不锈钢在650~850℃时效处理过程中存在σ相析出行为。当时效温度为850℃时,σ相析出最快;随着时效温度偏离850℃,σ相析出速度降低。经过1350℃固溶后,σ相析出温度整体提高,析出温度范围更宽。σ相析出后即发生迅速长大,在3 h内体积分数可达0.25%~1.75%;之后其生长速率逐渐减缓。σ相首先在铁素体与奥氏体相界处以小于1μm的近似球状颗粒形貌析出,之后沿着铁素体相中宽度在几微米的狭窄区域向铁素体内生长。2205双相不锈钢的时效处理温度影响σ相的析出行为,时效处理应在偏离850℃的温度下进行,以防止σ相的析出和快速长大。2205 duplex stainless steel was solid-solution treated at 1050℃and 1350℃for 30 min,and then aged at 650-1000℃for 0.5-1440 min.The microstructure andσphase were characterized by optical microscope(OM)and scanning electron microscope(SEM).The results show that the precipitation ofσphase in the 2205 duplex stainless steel after solid solution treatment at 1050℃occurs during aging treatment at 650-850℃.At 850℃,the precipitation ofσphase is the fastest,and the precipitation rate decreases when the aging temperature deviates from 850℃.After solid solution treatment at 1350℃,the precipitation temperature ofσphase rises in overall,and its range is wider.Theσphase coarsens quickly after precipitation and the volume fraction reaches 0.25%-0.75%within 3 h,then the growth rate ofσphase decreases with the increase of aging time.Theσphase precipitates at the phase boundary between ferrite and austenite with the morphology of quasi-spherical particles less than 1μm,then it grows in the narrow region of several microns along the width of ferrite phase.The aging temperature affects the precipitation behavior of 2205 duplex stainless steel,and the aging temperature should be away from 850℃to avoid the precipitation and growth ofσphase.

关 键 词：2205双相不锈钢 时效工艺 Σ相 析出 

分 类 号：TG142.71[一般工业技术—材料科学与工程]