大面积激光熔覆NiCrBSi合金组织结构

来源期刊：冶金分析2010年第10期

论文作者：邱星武

文章页码：37 - 42

关键词：激光熔覆； NiCrBSi合金； 组织； 大面积

Key words：laser cladding； NiCrBSi alloy； microstructure； large area

摘    要：采用CO₂激光器及六轴六联动三维激光加工机床对40Cr钢进行大面积激光熔覆处理,利用扫描电镜、金相显微镜、X射线衍射仪等仪器对熔覆层组织进行了研究。结果表明:激光熔覆涂层由熔覆区、结合区和热影响区三部分组成,涂层与基体呈冶金结合;涂层主要含γ-(Ni,Fe)、Ni₃(Fe,Si,B)、Cr₂₃C₆相;多道搭接试样受"二次加热"效应的影响,搭接结合区的组织粗大,形态多样复杂且易产生裂纹;多层叠加熔覆层中心区域枝晶分解得较完全,第一和第二层熔覆层交界处不足以完全形成平面晶,仍以柱状晶外延方式生长。

Abstract: Large area laser cladding on 40Cr steel was carried out by CO₂ laser and the six axes sixlinkages three dimensional laser processing machine,and the microstructure of cladding coating were studied by means of scanning electron microscope,metallographic microscope,X-ray diffractometer,etc.The results indicated that,the coatings of laser cladding were constituted by cladding zone,bonding zone and heat-affected zone;γ-(Ni,Fe),Ni₃(Fe,Si,B),Cr₂₃C₆ appeared as mainly phases in cladding layer;metallurgical bonding were formed between coating and substrate.Multitrack overlapping samples was affected by re-heat.The microstructure in bonding zone was coarse,multi-shaped,complicated and cracks were liable to appeare.Dendrite decomposed completely in multilayer overlay central area.The juncture between the first and the second cladding layers was not enough to form planar crystal,but still grew by columnar crystal extension.