The Research On Microstructures And Performances Of Cast Iron And Low Alloy Steel Surface By V-EPC Casting-penetration

Nowadays the industry entered a rapid development era while both thetraditional processing industry and emerging IT industry put forward some newrequirements for the development of the materials. Material development is anew challenge, so it requires researchers to innovation. Development andinnovation of materials should not completely abandon traditional materials,these materials have low cost, good performance a nd low environmentalpollution etc. We should continue to improve traditional materials and improvethe performance of the traditional materials on the condition of sustainabledevelopment.Metal material is one of the old traditional materials. The industrialperformance requirements of metal materials are higher and higher now, sowe need to continuously improve it. Steel material is a very common and widemetal materials and it cannot be replaced by other materials in some areassuch as cars, ships, bridges, mining machinery and construction.Within the scope of these applications, there are a lot of steel materialslosing useful value because of the wear. The wear parts are often localizedsurface of spare parts. It is not the best choice that the part surface wearmakes the whole part useless. So it is very important to improve the surfacemodification now.This article adopts the method of V-EPC casting-penetration surfacealloying process and we successfully make different alloy component layers ingrey cast iron and low alloy steel surface. Through the microscopicobservation it is found that there are a lot of compact structures, and the wearresistance of the alloy layer is much better than the substrate, so as toeffectively improve the abrasion resistance on the surface of the substrate.In this study, the Fe-Cr-Mo、Fe-Ni-Cr-Mo、Fe-Si-Ni-Cr-Mo3kinds of alloy layer are prepared in the surface of gray cast iron, meanwhile the NiCrBSialloy layer is made in the surface of low alloy steel. The thickness of the alloylayer ranges between1mm and2mm. Afterwards the alloy layer was observedand analyzed by the advanced materials analysis instruments, such asSEM(scanning electron microscopy), X-ray diffraction and etc. It can be foundthat there is no obvious boundary between the substrate and alloy layer. A lotof solid solutions and alloy compounds exited in this region, which means thechemical metallurgical reaction happened amo ng the molten metal and alloycoating powder. The bonding of alloyed layer and the substrate ismetallurgical.The wear experiment was conducted by the ML-100Type pin plate weartesting machine and the load is15N,25N,35N, respectively and the mesh ofthe sand paper is240,600,1000, respectively. The results of the substrateand alloy layer wear experiment showed that the abrasion resistance of thealloy layer is much better than the substrate, which is related to the alloycompounds and the solid solutions. Micro hardness testing results of alloyedlayer show that the hardness of the alloy layer is higher the substrate.