窄孔内壁激光金属沉积Stellite6合金耐磨层组织及性能研究  

Study on Microstructure and Properties of Stellite6 Alloy Wear-resistant Layer on the Inner Wall of Narrow Holes by Laser Metal Deposition

作　　者：王红顺 张峰 黄兆亮 王艳 庞义斌 周智文 高俊杰 WANG Hongshun;ZHANG Feng;HUANG Zhaoliang;WANG Yan;PANG Yibin;ZHOU Zhiwen;GAO Junjie(PipeChina North Pipeline Company Compressor-Set Maintenance Repair&Overhaul Center,Langfang 065000,China;HFYC(Zhenjiang)Additive Manufacturing Co.,Ltd.,Zhenjiang 212132,China)

机构地区：[1]国家管网集团北方管道有限责任公司压缩机组维检修中心,河北廊坊065000 [2]航发优材(镇江)增材制造有限公司,江苏镇江212132

出　　处：《电焊机》2024年第7期68-75,共8页Electric Welding Machine

摘　　要：为解决窄孔内壁堆焊的可达性差和提高304L不锈钢的耐磨性能,采用激光金属沉积的方式在深30 mm、直径14 mm的304L窄孔内壁制备了一层约2.5 mm厚、致密度为99.9981%、无裂纹、未熔合等缺陷的stellite6耐磨层。通过微纳CT、XRD、金相、硬度测试和摩擦磨损试验等方法,系统研究了耐磨层的组织、相组成、硬度分布和耐磨性能。结果表明,Stellite6耐磨层致密无缺陷,其显微组织从底部到顶部依次为平面晶、胞状晶、树枝晶和等轴晶。相组成主要为γ-Co、M_(23)C_(6)、CoCx及(Cr,Fe)_(7)C_(3)等。熔合线附近各种元素均匀分布,未出现明显聚集。耐磨层的显微硬度平均值是基体304L的2.38倍,且窄孔不同高度位置的显微硬度值相对稳定。耐磨层的磨损率较304L基体降低了29.3%,显示出优异的耐磨性能。该研究为大深宽比内孔壁激光金属沉积耐磨层在核电、能源动力等行业的应用提供了依据。To solve the poor accessibility of narrow hole inner wall surfacing and enhance the wear resistance of 304L stainless steel,a layer of stellite 6 wear-resistant coating with a thickness of approximately 2.5 mm,density of 99.9981%,and free of cracks and unfused defects was deposited on the inner wall of a 304L narrow hole with a depth of 30 mm and diameter of 14 mm using laser metal deposition.The microstructure,phase composition,hardness distribution,and wear resistance of the wear-resistant layer were systematically investigated through micro-nano CT,XRD,metallographic examination,hardness testing,and friction wear testing.The results revealed that the stellite 6 wear-resistant layer was dense and defect-free,with its microstructure transitioning from planar crystals at the bottom to cellular crystals,dendrites,and equiaxed crystals at the top.The phase composition mainly consists ofγ-Co,M_(23)C_(6),CoCx,and(Cr,Fe)_(7)C_(3),etc.Various elements are evenly distributed near the fusion line,with no significant aggregation.The average microhardness of the wear-resistant layer is 2.38 times that of the 304L matrix,and the microhardness values at different heights of the narrow hole are relatively stable.The wear rate of the wear-resistant layer is 29.3%lower than that of the 304L matrix,indicating excellent wear resistance.This study provides a basis for the application of laser metal deposition wear-resistant coatings on large depth-width ratio inner hole walls in industries such as nuclear power and energy.

关 键 词：激光金属沉积 窄孔内壁 Stellite6合金 组织性能 耐磨层 

分 类 号：TG456.7[金属学及工艺—焊接]