不同Cr含量高温合金中α-Cr相析出行为及作用  

α-Cr PRECIPITATION BEHAVIOR AND ITS EFFECT ON HIGH Cr-CONTAINING SUPERALLOYS

作　　者：董建新[1] 谢锡善[1] 

机构地区：[1]北京科技大学高温材料及应用研究室,北京100083

出　　处：《金属学报》2005年第11期1159-1166,共8页Acta Metallurgica Sinica

基　　金：国家自然科学基金资助项目50571015

摘　　要：为了对不同Cr含量高温合金中α-Cr相析出行为进行对比研究,优化高Cr合金中α-Cr相的组织形态.通过微观分析手段对不同Cr含量的GH169, GH625, GH648及两种高Cr实验合金进行α-Cr相析出行为的对比分析,同时通过特殊热处理对高Cr合金α-Cr相组织优化进行了初步研究.结果表明.Cr含量低于25%的GH169和GH625合金在标准热处理后均没有α-Cr相析出,但经过长期时效后α-Cr相依附于δ相和M6C的界面析出;而Cr含量大于30%的GH648合金以及更高Cr含量的两种实验合金,α-Cr相已直接从奥氏体基体中析出,并有不同的析出存在形态,随Cr含量增加,α-Cr相从短棒状和颗粒状向长片条状和层片状的析出方式变化.同时,通过特殊热处理优化α-Cr相组织分布形态,获得细小弥散分布的α-Cr相,为高Cr合金的发展奠定研究基础.The α-Cr precipitation behavior and its effects on the different Cr-containing superalloys, such as GH169, GH625, GH648 and two high-Cr tested alloys, were investigated by microstructure analysis approach in order to compare their behavior and optimize the α-Cr phase morphology. The results show that no α-Cr phase was observed after a standard heat treatment but with long-term aging the α-Cr phase precipitates and grows usually clinging to δphase in GH169 alloy and clinging to M6C carbide and δ phase in GH625 alloy. However, for high Cr-containing alloys （Cr〉30%, GH648 and two tested alloys）, the α-Cr phase with various morphologies precipitates directly from austenitic matrix and from short-plate to long acicular and lamellar shape.Furthermore, the optimization of α-Cr phase was initially studied by a special heat treatment in order to obtain fine and uniform α-Cr particles.

关 键 词：高温合金 高Cr合金 GH648 α—Cr相 

分 类 号：O642[理学—物理化学] TG132.32[理学—化学]