Erw Steel Pipe Surface Decarburization

Many life of erw steel pipe products and the degree of surface decarburization on steel pipe products. For example, steel pipe service life depends primarily on its fatigue strength and wear resistance, pipe steel surface decarburization if exceeded, will reduce carbide surface and wear as a strengthening phase phase, which will have a direct impact two performance. Furthermore, tool steel, bearing steel surface decarburization if not cleaned, will tool steel, bearing steel, the hardness and wear resistance of the surface layer is reduced and, when hardened, due to different changes in the volume leaving the outer surface of the workpiece cracks. The earliest physical absorption method using pressurized water to remove carbon dioxide, water regeneration after decompression. This simple equipment, but the purification of carbon dioxide removal is poor, the carbon dioxide outlet is generally 2% (by volume) or less, the power consumption is high. Nearly 20 years to develop the methanol washing method, propylene carbonate method, polyethylene glycol dimethyl ether method, compared with pressurized water decarbonization law, they have a high degree of purification, low energy consumption, recycling advantages of high purity carbon dioxide, and selective removal of hydrogen sulfide may, decarburization method is widely used industrially. So, how to prevent surface decarbonization steel pipe products is a problem in the production process should be noted. Foreign imports of wire rod decarburization of 0.02 ~ 0.04mm, wire rod surface can be done without Kobe, Japan, decarbonization, and the average depth of the domestic like product decarburization than 0.05mm. Need to take measures to change the situation. Decarbonization is the result of diffusion on the one hand when the diffusion of oxygen into the decarbonization is steel; hand outward diffusion of carbon steel. Looking at the results from the final decarburization layer can be formed only when the decarbonization rate than the rate of oxidation. When the oxidation rate is large, obvious decarburization phenomenon can not occur, ie after decarburization produce iron from iron oxide skin Jibei. Thus, the relatively weak oxidation atmosphere, the decarburization may be formed deeper. Cause surface decarburization atmosphere is primarily oxygen, water vapor and an oxidizing gas such as carbon dioxide. When in contact with the heated oxidizing gas wire surface oxidation and decarburization occurs simultaneously; affinity because the dissolved carbon in the iron and these gases is relatively large, so the carbon off the surface first. These gases are generally packed into the furnace; iron, rust residues and the drawing surface of the wire on the surface of the pipe, will be decomposed into the furnace after heating, the reaction of some of the oxidizing gas. We can purposefully control the furnace atmosphere, so that in reducing the state can effectively avoid surface decarburization.