高钨K416B铸造镍基合金高温蠕变期间碳化物演化行为  

CARBIDE EVOLUTION BEHAVIOR OF K416B AS-CAST Ni-BASED SUPERALLOY WITH HIGH W CONTENT DURING HIGH TEMPERATURE CREEP

作　　者：谢君[1] 于金江[1] 孙晓峰[1] 金涛[1] 孙元[1] 

机构地区：[1]中国科学院金属研究所,沈阳110016

出　　处：《金属学报》2015年第4期458-464,共7页Acta Metallurgica Sinica

基　　金：国家重点基础研究发展计划项目2010CB631200和2010CB631206;国家自然科学基金项目50931004资助~~

摘　　要：通过蠕变性能测试和组织形貌观察,研究了高钨K416B镍基合金高温蠕变期间析出相的演化行为.结果表明,铸态合金中g'相的尺寸不均匀,条状MC碳化物在枝晶间区域呈汉字型分布;在施加应力的高温蠕变期间,细小M6C碳化物可在形变基体中不连续析出,热力学分析认为:在应力诱导作用下,元素C偏聚在应力集中处,与W等碳化物形成元素结合,促使细小M6C相自基体中析出;同时,条状MC碳化物表面形成沟槽,并逐渐分解蜕变成粒状M6C相,其中,在条状MC相表面形成的附加应力是促使MC相不断溶解和发生球化的主要原因.ABSTRACT As-cast Ni-based superalloys with high W content are used extensively in the turbine vane of aero- engine due to their good heat resistance and temperature capability. During high temperature service, the creep de- formations and microstructure evolution are occurred in the using materials, and the creep behavior mainly de- pends on their chemical composition and microstructure, such as size, distribution and morphology of r＇ phase and carbides. Thereinto, the mophologies of carbide phases are closely related to creep resistance of the alloy. General- ly, the carbide particles displaying dispersive distribution may enhance the creep resistance of the alloy, while the carbide with continuous morphologies distributed in the boundaries, they may provide easy paths for crack propaga- tion and degrade the mechanical properties of the alloy. Besides the creep life of the alloy also depends on the mi- crostructure evolution under high temperature. But the evolution mechanism of carbides in K416B superaUoy dur- ing creep is still unclear up to now. For this reason, by means of creep property measurement and microstructure observation, the evolution behavior of precipitates in K416B Ni-based superalloy with high W content during high temperature creep has been investigated. The results show that the size of 7＇ phase is inhomogeneous in the as-cast alloy, and the stripe MC-carbide distribute in the inter-dendrite regions displaying Chinese structures. During high temperature creep applied stress, fine M6C carbide discontinuously precipitate in the deformed 7 matrix. The ther-modynamics analysis indicates that the carbon element segregates in the regions of stress concentration and com- bines with carbide-forming elements W etc, which promoted the fine M6C carbide to precipitate from they matrix. At the same time, the grooves are formed on the surface of stripe MC carbide, and then gradually decomposed and transformed into M6C particles. Thereinto, the additional press formed in the surface of stripe MC carbide

关 键 词：K416B镍基合金 蠕变 碳化物演化 热力学分析 

分 类 号：TG132.3[一般工业技术—材料科学与工程]