汽轮机末级动叶片水蚀损伤修复与防护试验研究  

TEST STUDY ON REPAIR AND PROTECTION FOR WATER EROSION DAMAGE OF FINAL-STAGE BLADES IN STEAM TURBINES

作　　者：李巍[1] 李太江[1] 王绍东[2] 刘庆伏[3] 王博[1] 

机构地区：[1]西安热工研究院有限公司,陕西西安710032 [2]华能丹东电厂,辽宁丹东118300 [3]华能上安电厂,河北石家庄050310

出　　处：《热力发电》2011年第1期40-44,共5页Thermal Power Generation

基　　金：中国华能集团科技项目(HNKJ06-G22)

摘　　要：基于电厂汽轮机末级动叶片水蚀损伤机理,对受损叶片进行手工钨极氩弧焊(GTAW)修复,并对焊接接头的组织性能进行试验。结果表明,焊缝硬度满足使用要求,焊接接头力学性能优良,焊接接头抗高周疲劳性能满足叶片工况要求。为了提高叶片抗水蚀性能,延长叶片使用寿命,对比分析了叶片超音速火焰喷涂NiCr和WC-Co金属陶瓷2种不同涂层的组织结构、机械性能、热震性能、磨粒磨损及冲蚀磨损性能。与WC-Co涂层相比,NiCr涂层具有优异的耐磨性能及抗冲蚀性能,可作为耐水蚀涂层应用在汽轮机末级动叶片上。Based on the mechanism of water erosion damage occurred on the final-stage blades in steam turbines,the damaged blades have been repaired by using gas tungesten arc welding（GTAW）,and the microstructure performance of welded joints being tested.Results show that the hardness of weld joints satisfies the requirements in application,the mechanical properties of weld joints is good,the high-cycle fatigue resistant behavior of the weld joints can meet the requirement of blades in service.In order to enhance the water erosion resisting performance of said blades to lengthen their service life,the microstructure,the mechanical properties,the thermal shocking behavior,the abrasive wear and erosion damage properties of two different coatings NiCr and WC-Co ceramet sprayyed using high speed oxygen fuel have been compared and analysed.Compared with WC-Co coatings,the NiCrceramet coating has excellent resistance to abrasion and erosion,it can be used on final-stage blades in steam turbines as water-resistant coatings.

关 键 词：汽轮机 末级动叶片 水蚀 焊接修复 超音速火焰喷涂 NICR涂层 WC-CO涂层 

分 类 号：TK263.3[动力工程及工程热物理—动力机械及工程] TG17[金属学及工艺—金属表面处理]