电焊机2024，Vol.54Issue(4)：43-49,7.DOI:10.7512/j.issn.1001-2303.2024.04.06
阀杆失效分析及其表面激光熔覆修复
Failure Analysis of Valve Stems and Their Laser Cladding Repair
郭毅军 1雷自成 1关永康 1张书军 1李洁 2李世亮2
作者信息
- 1. 陕西陕煤韩城矿业有限公司桑树坪二号井,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
- 折叠
摘要
Abstract
The failure analysis of the three-eccentric butterfly valve stem serviced in a Sang Shuping No.2 Mine gas extrac-tion system and the drain gate valve stem was systematically investigated and the main failure mechanical was homogeneous corrosion in H2S,CO2,SO2 medium.In order to improve the corrosion resistance of these stems,laser cladding with Inconel 625 alloy was proposed.Microstructure observation,chemical composition,microhardness and electrochemical tests were performed to evaluate the cladding layers.The results show that the Inconel 625 wire cladding layer and powder cladding layer are consisted of dendrite structures.The cladding layers are free from cracks and pores,showing good bonding with the base metal.The contents of Cr element are higher in the interdendrite regions than that in the dendrite regions.Particles which are rich in Nb are precipitated in the interdendritic regions.The cladding layers show quite uniform element distribution on the whole,where Ni,Cr,Mo,Nb elements present transitional distribution at the interface.The corrosion potential of the Inco-nel 625 cladding layer is higher than that of the base metal.The corrosion current density of the cladding layer Icorr(8.62×10-7 A/cm2)below that of the base metal(8.23×10-6 A/cm2).The charge transfer resistance of Inconel 625 cladding layer obtained by the equivalent circuit fitting is Rct 9.9×104 Ω·cm2,far higher than that of the base metal(Rct 2.6×103 Ω·cm2).It is concluded that the corrosion resistance of the cladding layer is better than that of the base metal.The repaired valve stems have been in service for 2 months in the coal mine without failure and still operates normally,while the new valve stems failed after only 1 month of service.It is proved that the Inconel 625 laser cladding layer has well protected the substrate.关键词
Inconel 625合金/激光熔覆/失效分析/阀杆/耐腐蚀性能Key words
Inconel 625 alloy/laser cladding/failure analysis/valve stem/corrosio resistance分类
矿业与冶金引用本文复制引用
郭毅军,雷自成,关永康,张书军,李洁,李世亮..阀杆失效分析及其表面激光熔覆修复[J].电焊机,2024,54(4):43-49,7.
