摘要
为解决某高硫煤种的超超临界火电机组12Cr1MoV钢过热器管因高温侵蚀、颗粒冲刷导致的减薄开裂失效问题,提出CMT立向下堆焊ERNiCrMo-3镍基焊丝的修复方法,研究送丝速度(7~11 mm/min)、摆动周期前进长度(1~5 mm)、摆宽(5~9 mm)、焊接速度(200~400 mm/min)对焊道成形(熔宽、余高、接触角)的影响,并对堆焊接头的组织和性能进行测试分析。结果表明,送丝速度(电流、电压)和焊接速度对焊道成形的影响相对较大;摆动周期前进长度与摆宽通过调控接触角优化焊缝搭接质量,余高可通过摆动周期前进长度调控。最优工艺参数下(送丝速度10 mm/min、焊接速度300 mm/min、摆宽7 mm、摆动周期前进长度3 mm),堆焊层厚度达2~3 mm,无裂纹、气孔等缺陷,与母材形成良好冶金结合。力学性能测试显示,堆焊层平均硬度233.4 HV,高于母材的157 HV;堆焊熔合面剪切强度545 MPa,优于母材标准要求(490 MPa)。焊缝组织为γ固溶体+析出相,过热区组织为贝氏体,正火区组织为贝氏体+少量珠光体,珠光体显著球化,不完全正火区组织为铁素体+贝氏体+珠光体,母材组织为铁素体+珠光体。该研究成果可以给12Cr1MoV过热器管的高效高质量修复提供参考。
To address the thinning and cracking failure issues caused by high-temperature corrosion and particle erosion in 12Cr1MoV steel superheater tubes of ultra-supercritical coal-fired power units burning high-sulfur coal,a repair method using CMT downward vertical surfacing with ERNiCrMo-3 nickel-based welding wire was proposed.The effects of wire feeding speed(7-11 mm/min),oscillation forward distance per cycle(1-5 mm),weaving width(5-9 mm),and welding speed(200-400 mm/min)on weld bead formation(weld width,reinforcement height,contact angle)were investigated.Microstructure and mechanical properties of the surfacing joints were systematically analyzed.Results indicated that wire feeding speed(current,voltage)and welding speed had relatively significant influences on weld bead geometry.The oscillation for‐ward distance and weaving width optimized weld overlapping quality through contact angle adjustment,while reinforcement height could be controlled by oscillation forward distance.Under optimal process parameters(wire feeding speed:10 mm/min;welding speed:300 mm/min;weaving width:7 mm;oscillation forward distance:3 mm),the surfacing layer thickness reached 2-3 mm without defects like cracks or porosity,achieving metallurgical bonding with the base metal.Mechanical testing showed the surfacing layer exhibited an average hardness of 233.4 HV,higher than the base metal's 157 HV.The shear strength at the fusion interface reached 545 MPa,exceeding the required standard for base metal(490 MPa).Microstructural analysis revealedγsolid solution+precipitates in the weld zone,bainite in the overheated zone,bainite+minor pearlite in the normalized zone with significantly spheroidized pearlite,ferrite+bainite+pearlite in the incompletely normalized zone,and ferrite+pearlite in the base metal.This study provides reference for efficient and high-quality repair of 12Cr1MoV superheater tubes.
作者
张焱
高利孝
白爱平
刘洋
王强
郭枭
孙洪伟
付文俊
ZHANG Yan;GAO Lixiao;BAI Aiping;LIU Yang;WANG Qiang;GUO Xiao;SUN Hongwei;FU Wenjun(Shaanxi Yulin Energy Group Hengshan Coal and Electricity Co.,Ltd.,Yulin 719000,China;Harbin Welding Institute Limited Company,Harbin 150028,China)
出处
《电焊机》
2025年第12期39-44,共6页
Electric Welding Machine
