激光重熔Co基合金堆焊层的组织和耐热疲劳性的研究  

Study on microstructure and thermal fatigue resistance of laser remelting Co-based alloy hardfaced layers

作　　者：洪永昌[1] 夏正文 

机构地区：[1]安徽工业大学材料科学与工程学院,安徽马鞍山243002 [2]浙江久力集团股份有限公司,浙江湖州313012

出　　处：《电焊机》2007年第4期50-54,共5页Electric Welding Machine

基　　金：安徽省教育厅自然科学研究项目(2005KJ036)

摘　　要：利用金相显微镜、扫描电镜与X射线衍射仪等分析手段,对经不同激光工艺参数重熔的Co基合金堆焊层进行了组织结构分析和耐热疲劳性试验的研究。试验结果表明:经焊条电弧焊(SMAW)获得的堆焊层经激光重熔后,组织变得细小、均匀和致密,主要由大量细小初生枝晶固溶体γ-Co与其间的共晶组织γ-Co+Cr23C6组成。不同激光工艺参数处理的重熔堆焊层的耐热疲劳性均比原始堆焊层好。重熔堆焊层在700℃时的耐热疲劳性要好于900℃时的耐热疲劳性。综合比较结果,激光功率为2.5kW,扫描速度为4mm/s获得的重熔堆焊层,在700℃时的耐热疲劳性最好。By means of optical microscope（OP）,scanning electron microscope（SEM） and X-ray diffraction instrument（XRD）,remehing hardfaced layers of Co-based alloy which were made with different parameters of laser remehing were studied.Microstructure and thermal fatigue resistance of the were also tested.After laser remehing,it showed that microstructure turned to be fine,uniform and compact.And it was composed of primary phase（γ -Co）and eutectic microstructure（γ -Co＋ Cr23C6）.Compared with the original hardfaced layers,thermal fatigue resistance of the remehing hardfaced layers with different laser parameters was all improved.And at the temperature of 700 ℃ ,thermal fatigue resistance of the remehing hardfaced layers was better than that at the temperature of 900 ℃,It was best when laser power was 2.5 kW,scanning speed was 4 mm.s^-1 at the temperature of 700 ℃.

关 键 词：激光重熔 钴基合金 堆焊层 组织 耐热疲劳性 

分 类 号：TG456.7[金属学及工艺—焊接]