线光斑激光熔覆Ni-Al金属间化合物工艺及组织研究  

Study on Process and Microstructure of Ni-Al Intermetallic Compound by Line Spot Laser Cladding

作　　者：李林森 王轲岩 余超峰 殷咸青[1] LI Linsen;WANG Keyan;YU Chaofeng;YIN Xianqing(Xi'an Jiaotong University,State Key Laboratory of Mechanical Behavior for Materials,Xi'an 710049,China)

机构地区：[1]西安交通大学金属材料强度国家重点实验室,西安710049

出　　处：《焊管》2024年第2期45-49,共5页Welded Pipe and Tube

基　　金：国家重点研发计划项目2.4“替代电镀铬的绿色表面处理技术”(项目编号2018YFB2002000);国家重点研发计划项目3.6“海洋装备水下原位高效增材修复技术与装备”(项目编号2022YFB4601803)。

摘　　要：为了提高P92钢的耐高温氧化性能,采用线光斑在P92钢基体表面激光熔覆Ni-Al金属间化合物,对熔覆工艺参数进行了筛选,并对试样的组织形貌和成份进行了分析。结果表明,在筛选后的熔覆工艺下试样熔覆层未发现裂纹,无开裂倾向;P92钢基体熔化较少,基体中Fe元素扩散至顶部含量不到5%,熔覆层中主要物相为Ni3Al和NiAl,熔覆层顶部至基体部分的显微组织由等轴晶向树枝晶、柱状晶和平面晶转变。当激光功率1 800 W、扫描速度2 m/min、送粉速度为17 r/min、送粉气流量为8 L/min时,可以减少基体熔化和Fe元素扩散,从而对解决激光熔覆时Ni-Al金属间化合物熔覆层开裂、钢基体中Fe元素扩散问题提供了思路。In order to improve the high-temperature oxidation resistance of P92 steel,laser cladding of Ni-Al intermetallic compounds on the surface of P92 steel substrate was carried out using a line beam spot.The cladding process parameters were screened,and the microstructure and composition of the samples were analyzed.The results showed that under the selected cladding process,no cracks were found at the microstructure of the cladding layer,and there was no tendency for cracking.At the same time,the melting of P92 steel matrix is less,and the Fe element in the matrix diffuses to the top less than 5%.Ni3Al and NiAl are the main phases in the cladding layer.The microstructure from the top of the cladding layer to the matrix part changes from equiaxed crystal to dendrite,columnar crystal and plane crystal.When the laser power is 1800 W,the scanning speed is 2 m/min,the powder feeding speed is 17 r/min,and the powder feeding gas flow rate is 8 L/min,the matrix melting and Fe element diffusion can be reduced.It provides a way to solve the problem of cracking of Ni-Al intermetallic compound cladding layer and Fe element diffusion in steel matrix during laser cladding.

关 键 词：线光斑 激光熔覆 裂纹 Fe元素扩散 

分 类 号：TG113.263[金属学及工艺—物理冶金]