Microstructure And Properties Of The Modified Surface On Guide Plate By Vacuum Infiltration Casting

Guide plate is an important accessory device for steel line rolling production,which mainly used for induction,gripping rolled piece(steel) passed.Guide plate contacts directly with high temperature work(1100℃),high-speed(6m/s) rolling sliding,although there is a mandatory cooling, but by the scene detection,the temperature of guide plate is about 300℃.It requires the guide plate has a high resistance to abrasion,heat fatigue and impact toughness.In this case,the guide plate materials generally have high hardness(63HRC) and good wear resistance of chilled iron,but it is susceptible to wear damage.Based on the guide plate special working condition,guide plate material has become really important for innovation and improvement.A composite penetration layer with Ni/WC or high chromium cast iron was fabricated by vacuum infiltration method(VIM) to improve the performance of guide plate.And to understand the performance of the penetration layer and combination strength between the layer and the matrix material(gray cast-iron),the test and analysis were carried out,such as microstructure,hardness, thermal fatigue,three-point bending,as well as high-temperature oxidation experiments.The results showed that:Various content of Ni/WC alloy powder was used.Preparation Various WC content of the composite layer fabricated by vacuum infiltration casting on the surface of cast iron.The thickness of the layer is 0.5-1.5mm.WC particles distributed homogenous.Micro-hardness of the layer was continuous change from high to low,with the surface to the substrate.The combination of matrix and the penetration layer is good.The penetration layer plays role of protection during high-temperature oxidation experiment in spite of various WC content.Compare the sample with different WC content in the layer,the smaller WC content in the layer,the better protection to the substrate.Interfacial bonding of FeCr between substrate and the penetration layer is good,the hardness of the layer was increased significantly.It also have good properties of thermal fatigue.Experiments was carried out at 800℃,the result shows that the penetration layer played a very good protection to the substrate.