Thermal spraying combined manufacturing process of lost foam cast ductile iron pipe fittings

Abstract

The invention discloses a thermal spraying combined manufacturing process of lost foam cast ductile iron pipe fittings. The thermal spraying combined manufacturing process comprises the following steps that a, lost foam is manufactured, specifically, foamed plastic is manufactured into real molds corresponding to the ductile iron pipe fittings in part structure and size; b, coating brushing is conducted, specifically, the real molds are assembled, combined and dried, the combined real molds are brushed with high-temperature preventing coating, and then the coating of the real molds is dried; c, thermal spraying treatment is conducted, specifically, the surface layer of the coating is subjected to thermal spraying treatment, the thermal spraying temperature is 50-250 DEG C, and the thickness of a thermal spraying material is no more than 1 mm; d, burying-in-box and modeling are conducted, specifically, the real molds subjected to thermal spraying operation are buried in a sand box and modeled; and e, casting and clearing are conducted, specifically, molten metal is poured into the sand box at the negative pressure, cooling, shot blasting, polishing clearing and a pressure test are conducted, and then finished products are obtained. The strength and flatness of a coating layer are improved through combination of thermal spraying, and the problem that the coating is likely to falloff, brushing is nonuniform, and consequently, the quality of the finished products is affected is well solved.

Description

technical field [0001] The invention relates to the technical field of casting engineering, in particular to a manufacturing process of a lost foam casting ductile iron pipe fitting combined with thermal spraying. Background technique [0002] The nodular cast iron pipe is made by adding magnesium or rare earth magnesium combined with gold nodularizing agent to the molten iron before pouring to spheroidize graphite and reduce stress concentration, so that the pipe has high strength, high elongation, impact resistance, corrosion resistance, good sealing, etc. Advantages of pipe fittings; the inner wall is lined with cement mortar, which improves the water delivery environment of the pipeline, increases the water supply capacity, and reduces energy consumption; the nozzle adopts a flexible interface, and the pipe itself has a large elongation rate, which makes the pipeline more flexible. In the buried pipeline, it can work together with the soil around the pipeline to improve ...

AI Technical Summary

Problems solved by technology

[0006] The present invention aims to provide a manufacturing process of lost foam casting nodular cast iron pipe fittings combined with thermal spraying, which combines thermal spraying to enhance the strength and smoothness of the coating layer, and solves the problem that the coating is easy to fall off and the coating is uneven. Finished product quality and quality issues

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