等离子表面渗铬渗碳耐磨合金层

利用铬是碳化物形成元素且与α-Fe无限互溶的条件,在廉价低碳钢或中碳钢表面进行等离子渗铬,形成表面高铬合金层,当表面含铬量达到40%以上并在一定范围内渗层成分呈平缓的梯度分布时,再进行等离子渗碳,形成高铬高碳合金层。合金层中的含铬碳化物在固体状态下形成,属于二次碳化物。由于渗碳温度低,合金层的含铬量高,所形成的铬碳化物弥散、细小、均匀,当表面含碳量达2.8%以上时没有共晶莱氏体碳化物组织,表面高铬高碳合金层经淬火及回火处理后表面硬度达到HV1800。磨损试验表明,与淬火GCr15材料相比其耐磨性能提高8倍以上。

Wear-Resistant Alloying Layer of Plasma Surface Chromizing and Carburizing

The first plasma chromizing is achieved on cheaper low carbon steel surface and formed high chrome layer. The surface composition is more than 40% for chromium is infinity dissolving into α-Fe. The composition of alloyed layer distributes flat and grads. Afterward plasma carburizing is proceeded on alloyed high chromium layer. The carbonization of alloyed layer is secondly carbides and separated out from solid. The carbonization is dispersion, thin, uniformity. The surface contain carbon is morn than 2.8%. There is no ledeburite on alloyed layer. The surface hardness is 1800HV after quenching and tempering .The wear resistant is 8 times than GCr15 steel.