The Research On Properties And Fabrication Of Ni Based Ceramic Particles Composite Infiltrated Layer On Cast Steel

Guide plate is an important accessory device for steel line rolling production, which mainly used for induction, gripping rolled piece (steel) passed. The circumstance of guide plate is special.Guide plate contacts directly with high temperature work (1100℃), high-speed (6m/s) rolling sliding, so the wear of guide plate is critical, and it's necessary to make improvement and have innovation on the guide plate material, Based on the guide plate special working condition, A composite penetration layer with Ni/Al2O3 or Ni/WC was fabricated by cast infiltration method.In this paper the anti-wear, thermal fatigue, as well as high-temperature oxidation properties of composite infiltrated layer which fabricated with caat infiltration are investigated by microstructure, hardness, thermal fatigue, three-point bending, as well as high-temperature oxidation experiments.The results showed that:The composite infiltrated layer of different Al2O3,WC contents whose thickness is 1～2mm, the layer's texture is compact, combined well. The layer's macro hardness is larger than matrix's macro hardness. The layer's micro hardness shows continuous gradient variety, from surface to the matrix, the hardness from larger to tiny, and in the inferior surface it reaches the maximum. In three-points bending experiment, differ from the matrix, in the load-movement diagram a platform turns up. When it is larger than the critical value, the micro cracks turn up on composited infiltrated layer's surface, with the load increases, the cracks extend, from the texture analysis the combination between composited layer and matrix is good. The complicate infiltrated layer that of different Al2O3 contents have the same fracture style, the matrix's fracture style is ductile fracture, the complicate layer's fracture style is elevage fracture. The complicate infiltrated layer that of different WC contents have the same fracture style, the matrix's fracture style is ductile fracture, the complicate layer's fracture style is elevage fracture. Ni/Al2O3 composite infiltrated layer's friction and wear properties is influence by sliding linear velocity and normal load.with in certain load range,the wear rate has direct ratio with normal load;when pressure fixed,with the sliding linear velocity increases,the wear rate decreases. Ni/Al2O3 composite infiltrated layer's friction coefficient is influenced by sliding linear velocity and normal load.with the normal load increases the friction coefficient of counterpart decreases,the friction coefficient has no relation with sliding linear velocity. under room temperature and has no lubrication,Ni/Al2O3 composite infiltrated layer's wear mechanism mainly are adhesion wear, abrasion wear and fatigue wear. After certain times of thermal fatigue circulation, on composite infiltrated layer surface there turns up micro cracks, and with the oxidation, the micro cracks turn up on infiltrated layer's surface and combination zone between infiltrated layer and matrix, in high temperature oxidation experiment, no matter the WC contents and oxidation time, the composite infiltrated layer always has certain protection to the matrix, the fewer of the WC content, the better of protection of composite infiltrated layer.