Cr钢汽轮机转子轴颈现场激光修复工艺与应用

Procedure and Application of Laser Cladding Repair of 9Cr Steel Rotor Journal in Steam Turbines

超超临界汽轮机9Cr钢转子的轴颈油封区域可能发生磨损,磨损产生的铁屑与润滑油混合,堆积在油封齿之间,会不断加剧磨损,因此需要进行维修。在电厂现场采用激光熔覆修复工艺,熔覆材料为1CrMo粉末。1CrMo激光熔覆金属的耐磨性能和断裂韧性较高,同时具有优良的熔覆工艺性能,可以在焊态下使用。使用机器人作为执行工具,通过盘动转子实现了连续施焊,同时采取了加工坡口、预热、层间清理、熔覆退火焊道等措施,避免了转子变形,获得了质量优良的熔覆层。该工艺方案在9Cr钢转子的现场和返厂修复中的多次应用实践表明其适用于转子轴颈的现场修复,焊态1CrMo层可以满足转子轴颈的长期运行要求。研究成果可以为9Cr钢高、中压转子轴颈修复提供技术参考。

On oil sealing region of 9Cr steel rotor journal in ultra-supercritical steam turbine,abrasion may occur.If worn steel debris mixed with lubricating oil piles up among oil sealing teeth,the abrasion will be aggravated,so the repair of unit will be necessary.A laser cladding procedure with 1CrMo as cladding powder was proposed,which had good wear⁃resisting property,breaking tenacity as well as satisfying cladding performance.It could be used as welded.Using robot as actuator,continuous welding was realized with the rotors being rotated.Meanwhile,the measures of machining weld grooves,preheating,inter⁃pass cleaning and annealing laser beads were used to avoid welding imperfection or rotor distortion so that good cladding layer could be obtained.This cladding scheme has been applied to many 9Cr steel rotor journals on site and in workshop of manufacturer,and the practical experience show that it is suitable for on⁃site repairing,and the as⁃welded 1CrMo cladding metal can meet the requirements of long⁃term operation of the repaired rotors.The research result can provide technical reference for laser cladding repair of 9Cr rotor journal in steam turbine.