摘要
在20钢表面进行等离子Mo-Cr共渗及等离子超饱和渗碳复合处理,合金层接近钼系高速钢成分。表面Mo含量达到12%左右,Cr含量达到4%左右。等离子渗碳合金层表面含碳量达到2.0%以上,超过了平衡碳的计算值。经X–射线衍射分析,碳化物主要类型为M23C6、M7C3、M6C型,尺寸1ìm左右。试样经随后淬火+低温回火和淬火+深冷处理(-196℃)+低温回火两种工艺,使表面高速钢层获得马氏体基体上均匀分布的细小弥散的碳化物组织,没有粗大的共晶莱氏体碳化物。经深冷处理的试样表面硬度达到1600HV,明显高于未经过深冷处理工艺的高速钢层表面硬度(1000HV左右)。用WTM-1E球盘式摩擦磨损试验仪,进行摩擦磨损试验。结果表明:经等离子复合处理的表面高速钢层,与渗碳淬火及低温回火的试样对比,摩擦因数减小,仅有0.07~0.08。
This paper deals with the composite treatment of Mo–Cr plasma surface alloying and plasma super-saturation carburizing on 20 carbon steel substrate.The composition of surface layer is close to that of molybdenum high speed steel. The Mo,Cr, C contents reach to 12%,4% and morn than 2.0 % respectively. The carbon content in surface layer exceeds the balanced value.The main carbide types are M23C6、M7C3and M6C. their size is less than 1um. The following heat tratment was conducted using two processes of quenching +low temperature tempering and quenching +deep cold (-196 ℃) treatment + low temperature tempering. The martensite structure with uniform, fine and dispersive carbides in the surface layer was obtained, no thick eutectic ledeburite carbide was found. The surface hardness reaches 1600HV after deep cold treatment, it is obviously higher than that of conventional treatment. The friction coefficient is only 0.06~0.07, much lower than that of conventional carburizing steel.
出处
《中国表面工程》
EI
CAS
CSCD
2004年第6期15-18,共4页
China Surface Engineering
基金
国家自然科学基金
上海宝钢集团公司联合资助项目(50374050)
山西省自然科学基金项目(20031050)
关键词
等离子
碳化物
合金化
高速钢
深冷处理
plasma
carbide
alloying
high speed steel
deep cold treatment