预热温度对5CrNiMo钢表面堆焊Stellite6涂层组织和性能的影响  

Effect of Preheating Temperature on Microstructure and Properties of Stellite6 Coating Surfacing on 5CrNiMo Steel

作　　者：张鹏 崔明亮 傅强[2] 袁武华[2] ZHANG Peng;CUI Mingliang;FU Qiang;YUAN Wuhua(Deyang Wanhang Die Forging Co.,Ltd.,China National Erzhong Group Co.,Deyang 618013,China;College of Materials Science and Engineering,Hu'nan University,Changsha 410082,China)

机构地区：[1]中国第二重型机械集团,德阳万航模锻有限责任公司,四川德阳618013 [2]湖南大学材料科学与工程学院,湖南长沙410082

出　　处：《热加工工艺》2020年第18期104-107,110,共5页Hot Working Technology

摘　　要：通过在5CrNiMo模具基材上用等离子弧堆焊Stellite6涂层,研究了预热温度对Stellite6涂层组织和硬度的影响。结果表明,堆焊层组织主要由树枝状晶体的Co固溶体和枝晶间的Co-Cr与碳化物形成的共晶组织组成,预热温度的提高延缓了堆焊层冷却过程,导致堆焊层中部的晶粒大小随预热温度的升高而增大。预热温度的提高改变了碳化物的形貌,预热温度为300℃时,碳化物分布最为均匀,柱状晶晶粒最小,是较为理想的组织。随预热温度的升高,热影响区针状马氏体减少且变细。热影响区马氏体的形成是其硬度偏高的原因,当预热温度为300℃时,热影响区的硬度最为均匀。Stellite6 coating was cladded on 5 CrNiMo substrate by plasma transfer arc welding, then the effects of preheating temperatures on the microstructure and hardness of Stellite6 coating were studied. The results show that the structure of the surfacing layer is mainly composed of the dendritic Co solid solution and the eutectic structure formed by the Co-Cr and carbide between the dendrites. The increase of the preheating temperature delays the cooling process of the surfacing layer, resulting in the middle of the surfacing layer. The grain size increases with increasing preheating temperature.The increase in preheating temperature changes the morphology of carbides. When the preheating temperature is 300 ℃, the distribution of carbides is the most uniform and the columnar crystal grains are smallest, which is an ideal structure. As the preheating temperature increases, the needle-shaped martensite in the heat affected zone decreases and becomes thinner. The formation of martensite in the heat affected zone is the reason for its higher hardness. When the preheating temperature is 300℃, the hardness of the heat affected zone is the most uniform.

关 键 词：预热温度 堆焊 Stellite6合金 组织 性能 

分 类 号：TG174[金属学及工艺—金属表面处理]