Microstructure And Properties Research Of Iron Base Alloy Powder Flame Spraying Remelting Layer

In this paper, I use oxyacetylene flame spraying method in 27 SiMn steel substrate,prepare of iron base alloy powder coating; use orthogonal experiment method, analyze affect of the performance of coating in different oxyacetylene flame spraying process parameters and the composition of different powder on the microstructure and wear resistance corrosion resistance of after remelting. Use rockwell hardness tester, micro hardness tester, metallographic microscope, X-ray diffraction, scanning electron microscopy (sem) and other laboratory equipment to study organization structure and performance of layer of spray before and after argon arc remelting.The results show that Oxyacetylene flame spraying combination between coating and substrate is mainly mechanical bond, trace the metallurgical combination of complementary. Coating contains the deformation of particles, not melt particles, oxide and a small amount of porosity. When the spray layer thickness to 1 mm,substrate surface roughness is 36 mesh sandpaper coarsening processing, spraying distance is 100 mm, porosity of 13.42%, coating of microhardness HV446.3, bond strength is 24.6 MPa, comprehensive performance is best. Through the tungsten electrode argon arc remelting processing flame spraying layer, Iron base alloy remelting layer and metallurgical bonding to the substrate, compact structure, almost no pore. After the arc remelting remelting layer is divided into three zones:the fusion zone, combining zone, heat affected zone. At the bottom of the remelting layer and matrix interface in a narrow range of flat zone, with the increase of distance from the interface, remelting layer organization for cellular crystal and dendritic crystal area, the last is a small amount of isometric. G302 composite powder tungsten argon arc welding of remelting layer organization is martensite and residual austenite. Heat affected zone for westergren body organization organization, the organization is relatively bulky. In terms of ratio of alloy:Iron base alloy powder of remelting layer hardness and wear resistance increase is associated with the composition of alloy powder, and remelting layer hardness increase with the addition of ferrochrome, first after stable at the same time with the increase of WC was slightly lower after the first increase trend. When the iron base composite powder in adding the WC is 15%, chromium iron content was 9%, remelting layer has the best hardness and abrasion resistance, hardness of HRC64.4, the mass loss per unit area is 247.7 g/m~2. In terms of corrosion resistance, along with the increase in chromium iron content, remelting layer corrosion resistance also increase subsequently.