718H模具钢等离子熔覆涂层的组织和性能研究.pdfVIP

HotWorkingTechnology2014，Vo1．43，No．8

718H模具钢等离子熔覆涂层的组织和性能研究

费丽爽，肖小亭，胡永俊，吝嘉坤

r广东工业大学材料与能源学院，广东广州510006)

摘要：采用等离子熔覆技术在718H模具钢表面熔覆铁基合金粉末，借助光学显微镜、X射线衍射仪、扫描电镜、

能谱仪、显微硬度计和材料表面性能综合测试仪对熔覆层的显微组织、化学成分、物相组成、显微硬度和摩擦磨损性能

进行了分析。结果表明：等离子熔覆铁基合金粉末的熔覆层的组织近表面为细晶区，中间为柱状晶，熔覆层与热影响区

的交界处有一条平面晶组织，熔覆层与基体形成了冶金结合，热影响区组织为板条状马氏体；从基体到表面硬度大致呈

梯度分布，熔覆层的硬度达到800HV，大于基体材料的硬度；熔覆层中有较多MC，碳化物和-(Cr-Ni-Fe—C)合金固溶

体相，磨损量小于基体材料的，熔覆层的耐磨性明显好于基体材料。

关键词：等离子熔覆；718H模具钢；显微组织；显微硬度；耐磨性

中图分类号：TG174文献标识码：A文章编号：1001—3814(2014)08—0142—03

StudyonMierostructureandPerformanceofCoatingon718H

MoldSteelbyPlasmaCladding

FEILishuang，XIAOXiaoting，HUYongjun，LlNJiakun

(SchoolofMaterialsandEnergy，GuangdongUniversityofTechnoloyg，Guangzhou510006China)

Abstract：Fe-basedalloylayerwascoatedon718Hmoldsteelsurfacebyplasmacladdingtechnoloyg．The

microstructure，phaseconstituent，chemicalcomposition，hardnessandwearresistancewerecharacterizedbyOM，XRD，

SEM，EDS．HV一1000micro．harndesstesterandmaterialsurfacecomprehensiveperformancetester．Theresultsshowthatfine

grainsareobservednearthesurfaceofhtecoatedlayer，andcolumnarrgainstrucutresareobservedunderthesurface．Athte

interfacebetweencladdinglayerandheataffectedzone，aplanargrainstrucutreisdetected，andthecoatingismetallurgically

bondedwihthtemarx．Theheataffectedzoneisobservedtobestripmartensitestrucutre．Agradientincreasingdistribution

ofharndessisdetectedfromthemarxtohtecoatingsurface，wherethesurfaceofcoatinghasthemicro-hardnessashighas

800HV．M7C3carbideand一(Cr-Ni—Fe—C)alloysolidsolutionarefoundinthecoating．Thewearmasslossofhtecoatingis

characterizedtobelowerthanthatofmatrix’s，indicatingthewearresistanceofcoatingmaterialisbetterthanthatofmatrix．

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