三偏心蝶阀失效分析及其司太立合金等离子熔覆修复研究  

Failure Analysis of Three-eccentric Center Butterfly Valve and Its Plasma Cladding Repair with Stellite alloy

作　　者：雷自成 郭毅军 关永康 张书军 李洁 李世亮 冯海波 LEI Zicheng;GUO Yijun;GUAN Yongkang;ZHANG Shujun;LI Jie;LI Shiliang;FENG Haibo(Sang Shuping No.2 Mine,Shaanxi Shanmei Hancheng Mining Co.,Ltd.,Hancheng 715407,China;Xian intelligent Remanufacturing Resesrch Institute Co.,Ltd.,Xi’an 710018,China)

机构地区：[1]陕西陕煤韩城矿业有限公司,陕西韩城715407 [2]西安智能再制造研究院有限公司,陕西西安710018

出　　处：《电焊机》2024年第7期125-131,共7页Electric Welding Machine

摘　　要：针对某煤矿瓦斯抽放系统三偏心蝶阀密封面和轴孔的失效进行系统分析,确定其主要发生的是均匀腐蚀失效。该三偏心蝶阀长期在饱含凝露水及强腐蚀性气体(H_(2)S、CO_(2)、SO_(2))的瓦斯介质中服役,针对该服役环境,提出在其密封面和轴孔表面等离子熔覆司太立12合金的修复方案。对司太立12等离子熔覆层进行系统的显微组织观察、化学成分测试、显微硬度测试,以评估其可靠性。结果表明:司太立熔覆层主要为胞状树枝晶结构,熔覆层与基体结合良好,未见裂纹和气孔缺陷;熔覆层中的胞状枝晶主要为Co基固溶体,在枝晶间连续分布着富Cr相(Cr基固溶体+Cr的碳化物共晶组织)网状结构,富W相(W_(2)C碳化物+Co基固溶体)在富Cr网状结构中呈现不连续分布;司太立12等离子熔覆层的显微硬度为375~450 HV0.3,高于基材(100~150 HV0.3)和原始不锈钢套(200~250 HV0.3)。修复后的蝶阀在煤矿中服役4个月未发生失效,而未处理的新蝶阀服役1个月就发生失效,说明蝶阀密封面及轴孔所采用的司太立12等离子熔覆层对基材有较好的保护作用。The failure analysis of the sealing face and shaft hole of the three-eccentric butterfly valve serviced in a coal mine gas extraction system was systematically investigated and the main failure mechanical was homogeneous corrosion.This failed three-eccentric butterfly valve is serviced in the high temperature gas rich in liquid and highly corrosive gas(H_(2)S,CO_(2),SO_(2)).Based on this,the sealing face and shaft hole is suggested to plasma cladding with stellite 12 alloy.Microstructure observation,chemical composition and microhardness tests were performed to evaluate the cladding layer.The results show that the stellate cladding layer is consisted of cellular dendrites.The cladding layer is free from cracks and pores,showing good bonding with the base metal.The cellular structure is Co-based solid solution.The net structures rich in Cr element(Cr-based solid solution and chromium carbides)present continuous distribution among these cellular structures.Some W rich structures composed by W_(2)C and Co-based solid solution are distributed in the net structure.The microhardness of the stellite cladding layer is 375~450 HV0.3,which is higher than the base metal(100~150 HV0.3)and the original stainless steel sleeve(200~250 HV0.3).The repaired butterfly valve has been in service for 4 months in the coal mine without failure,while the new butterfly valve failed after only 1 month of service.It is proved that the plasma cladding of stellite 12 alloy on the sealing face and shaft hole has well protected the substrate.

关 键 词：等离子熔覆 失效分析 蝶阀 显微组织 

分 类 号：TG115[金属学及工艺—物理冶金]