送粉方式对WC颗粒增强铁基熔覆层的影响  

Influence of Powder-Feeding Mode on Microstructure of WC Particles-Reinforced Fe-based Cladding Layer

作　　者：金绍彤 杜晓东[1] 钟一鸣[1] 吴刚[1] 

机构地区：[1]合肥工业大学材料科学与工程学院,合肥230009

出　　处：《表面技术》2016年第10期96-102,共7页Surface Technology

摘　　要：目的改进后送粉方式在45^#钢表面利用等离子喷焊技术制备WC颗粒增强铁基耐磨熔覆层。方法利用等离子喷焊机和加装改进的后送粉装置制备熔覆层,通过金相光学显微镜（OM）、扫描电子显微镜（SEM）、能谱仪（EDS）和X射线衍射（XRD）等测试分析手段研究熔覆层的显微组织、相组成和成分特征。结果后送粉电压和送粉方式对WC颗粒分布的影响较大,通过调整送粉电压、改进后送粉方式可以改善WC的分布以及WC粉末的利用率。球形铸造WC与多边形结晶WC相比,前者粉末利用率显著提高,WC颗粒分布更均匀,熔覆层的平均维氏硬度达到1500HV10以上,高于后者。熔覆层出现鱼骨状莱氏体组织和大量的碳化物。结论改进的后送粉方式包含了同步送粉和后送粉的优点,使WC颗粒分布均匀,且WC未出现很大程度溶解,保留原始形态。送粉电压为10 V时,后送粉的熔覆效果较好。球形铸造WC增强熔覆层的性能较多边形结晶WC有很大提高。The work aims to prepare WC particles-reinforced Fe-based wearproof cladding layer on the surface of 45# steel by plasma spray welding provided that back powder-feeding mode was improved. The cladding layer was prepared by plasma spray welding machine and improved back powder-feeding device. Test analysis methods including optical microscope（OM）, scanning electronmicroscopy（SEM）,X-ray diffractometer（XRD） and energy dispersive spectrometer（EDS） were used to study microstructure, phase composition and chemical compositions of the cladding layer. Since the distribution of WC particles was mainly determined by back powder-feeding voltage and powder-feeding mode, the distribution of WC particles and utilization ratio of WC powder could be improved by adjusting the powder-feeding voltage and improving back powder-feeding mode. Meanwhile, compared with spherical cast WC and polygonal crystal WC, utilization ratio of the former powder was increased obviously, WC particles were distributed more uniformly and average Vickers hardness of the cladding layer reached over 1500HV10, higher than the latter. Fishbone-like ledeburite structure and a mass of carbides were detected in the cladding layer subject to back-feeding spherical cast WC process. The improved back powder-feeding mode possesses the advantages of synchronous powder feeding and back feeding, providing uniform distribution of WC particles and retaining the original form without significant dissolution. Better cladding effects are made at powder-feeding voltage of 10 V. Spherical cast WC- reinforced cladding layer presents better performance than that of polygonal crystal WC.

关 键 词：等离子喷焊 改进后送粉方式 WC颗粒增强 WC分布 粉末利用率 显微组织 

分 类 号：TG174.442[金属学及工艺—金属表面处理]