超超临界汽轮机阀门部件的两层等离子喷焊司太立合金工艺研究  

Study on Processing of Plasma Transferred Arc Depositing Two-layer Stellite Alloy on Valve Components of Ultra-supercritical Steam Turbine

作　　者：郭洋[1] 黄岚[1] 范华[1] 陈兴东[1] GUO Yang;HUANG Lan;FAN Hua;CHEN Xingdong(Sate Key Laboratory of Long--life High Temperature Materials,Dongfang Turbine Co,Ltd.,Deyang Sichuan,618000)

机构地区：[1]长寿命高温材料国家重点实验室,东方汽轮机有限公司,四川德阳618000

出　　处：《东方汽轮机》2020年第2期44-48,共5页Dongfang Turbine

摘　　要：为了满足超超临界汽轮机阀门部件表面大面积堆焊厚度为4.5 mm司太立合金层的要求,本文选择合适的预热、等离子喷焊、后热及去应力热处理等工艺参数,采用stellite 6#合金粉末在调质态F92锻件表面直接进行大面积两层等离子喷焊,通过分析司太立合金堆焊层的外观成型、无损检查、室温硬度、稀释率和金相组织来评价等离子喷焊工艺的合理性。结果表明,采用合理的等离子喷焊工艺参数可获得良好的组织与性能、无焊接缺陷、稀释率低于10%的大面积两层等离子喷焊司太立合金堆焊层;司太立合金层的维氏硬度在400HV10以上,且第二层司太立合金层硬度略高于第一层;堆焊层组织主要为钴基固溶体+晶间片状碳化物共晶组织,而两层堆焊层之间存在胞状晶固溶体+晶间片状碳化物共晶组织。To meet the requirement of surfacing valve parts of ultra-supercritical steam turbine with 4.5 mm stellite alloy layer, the optimizing parameters of plasma transferred arc depositing(PTA) processes were selected to manufacture the two-layer Stellite 6 alloy coating on F92 alloy component, which were evaluated by analyzing the appearance, non-destructive inspection, microhardness, dilution ratio and microstructures of the Stellite alloy depositions. The results showed that a large area of Stellite coating with good microstructures, properties, no welding defects and low dilution( less than 10%) could be obtained by PTA processing;the Vickers hardness of Stellite alloy layer was more than 400 HV10, and the microhardness of the second Stellite alloy layer was slightly higher than that of the first one;the microstructure of depositing layers was mainly consisting of the cobalt based solid solution + intergranular sheet, and the interfaces microstructure between the two layers was cellular crystal solid solution and lamellar carbide eutectic.

关 键 词：Stellite 6# 合金粉末 等离子喷焊 大面积 两层 

分 类 号：TG456[金属学及工艺—焊接]