SAF2507双相不锈钢二次急冷淬火成形析出相的析出行为  

Precipitation Behaviors of SAF2507 Duplex Stainless Steel Precipitated Phase by Secondary Quench Stamping

作　　者：郭幼丹[1] 程晓农[2] GUO Youdan;CHENG Xiaonong(School of Marine Equipment and Mechanical Engineering,Jimei University,Xiamen 361021,Fujian,China;School of Materials Science and Engineering,Jiangsu University,Zhenjiang 212013,Jiangsu,China)

机构地区：[1]集美大学海洋装备与机械工程学院,福建厦门361021 [2]江苏大学材料科学与工程学院,江苏镇江212013

出　　处：《材料导报》2025年第9期171-177,共7页Materials Reports

基　　金：国家自然科学基金(50772044);福建省科技计划引导性重点项目(2016H0023);福建省自然科学基金(2014J01200)。

摘　　要：采用二次急冷淬火热成形技术进行SAF2507双相不锈钢(SAF2507 DSS)螺旋桨叶片成形,并采用扫描电镜(SEM)、EDAX能谱仪(EDS)、透射电子显微镜(TEM)等研究SAF2507 DSS热成形过程中析出相的析出行为。结果表明:SAF2507 DSS二次急冷淬火热成形中的析出相以σ相和χ相为主,其中,热成形温度与冷却速度是决定相的析出行为的关键因素。成形时,σ相和χ相的析出均存在着一个析出转变温度:当成形温度低于950℃时,σ相的析出随成形温度升高而增多,当成形温度高于950℃时,σ相的析出随成形温度升高而减少;当二次急冷淬火热成形温度低于850℃时,χ相的析出随成形温度升高而增多,当二次急冷淬火热成形温度高于850℃时,χ相停止析出并逐渐转换为σ相。急冷时,σ相和χ相有效形核并开始析出均存在一个析出临界冷却速度v_(σ)和v_(χ),当冷却速度大于析出临界冷却速度时,σ相和χ相均不能有效地形核析出。此外,二次急冷淬火热成形时,SAF2507 DSS中Cr、Mo、Ni等元素的远程扩散与偏析,成形时表面氧化和表面氧化物情况和成形力作用下晶粒细化情况均会影响σ相和χ相的形核和析出。The forming of SAF2507 duplex stainless steel(SAF2507 DSS)propeller blade was carried out by the technique of secondary quench stamping.The precipitated phase precipitation behavior during SAF2507 DSS forming was studied by scanning electron microscopy(SEM),EDAX energy dispersive spectrometer(EDS),transmission electron microscopy(TEM),etc.The results show thatσphase andχphase are the main precipitates during SAF2507 DSS secondary quench stamping.The forming temperature and cooling rate are the key factors to determine the precipitation behavior.There exists a transition temperature for bothσandχphase precipitation during secondary quench stamping.When the temperature is less than 950℃,the amount ofσphase increases with the increase of temperature,and when the temperature is greater than 950℃,the amount ofσphase decreases with the increase of temperature.When the temperature is less than 850℃,the amount ofχphase increases with the increase of temperature.When the temperature is more than 850℃,the precipitation ofχphase stopped and gradually transforms intoσphase.During rapid cooling,σphase andχphase nucleate and precipitate effectively,and there is a precipitation critical cooling rate v_(σ)and v_(χ).When the cooling rate is greater than the critical cooling rate,neitherσphase norχphase can nucleate and precipitate effectively.In addition,many factors such as the long distance diffusion and segregation of Cr,Mo and Ni in SAF2507 DSS,surface oxidation and surface oxides,and grain refinement under forming force,can affect the nucleation and precipitation ofσphase andχphase during the secondary quench stamping too.

关 键 词：SAF2507双相不锈钢 二次急冷淬火成形 析出相 成形温度 临界冷却速度 

分 类 号：TG172.8[金属学及工艺—金属表面处理] TG142.71[金属学及工艺—金属学]