Production process for efficiently and centrifugally casting nodular cast iron pipe through hot mold

Abstract

The invention discloses a production process for efficiently and centrifugally casting a nodular cast iron pipe through a hot mold, and relates to the field of nodular cast iron pipe casting. The production process comprises the following steps that S1, paint is sprayed to the inner wall of a metal pipe mold, S2, a sand core is arranged at the socket end of the pipe mold, S3, pouring is conducted, S4, cooling is conducted, S5, pipe drawing is conducted, and S6, cleaning is conducted. In the step S1, when the paint is sprayed, the temperature of the pipe mold is 110-130 DEG C, the spraying thickness of the paint is 0.5-0.8 mm, and the diameter of a nozzle is 3 mm; in the step S3, the pouring temperature is 1290-1340 DEG C, the adding amount of a stream nucleating agent is 0.8% of the total weight of molten iron, and the adding amount of pipe mold powder is 0.3% of the total weight of the molten iron; and in the step S5, the pipe drawing temperature is 700-750 DEG C. According to the production process, the preparation time before molten iron pouring is shortened, the molten iron solidification time is shortened, the demolding temperature is increased, and the pouring period of each pipe is shortened; and meanwhile, the adding amount of the pipe mold powder and the adding amount of the stream nucleating agent are increased, and the quality of cast pipes is not reduced while the production efficiency is improved. After improvement, the production efficiency of the DN1500 pipes reaches 5-6 pipes per hour.

Description

technical field [0001] The invention relates to the field of casting of ductile iron pipes, in particular to the field of thermal mold centrifugal casting of ductile iron pipes, in particular to a production process of high-efficiency thermal mold centrifugal casting ductile iron pipes. Background technique [0002] The production process of large-diameter ductile iron pipes by thermal molding method evolved from resin sand mold centrifugal casting ductile iron pipes. In the original technology, the production process of resin sand mold centrifugal casting ductile iron pipes was used to manufacture ductile iron pipes. The production efficiency and It is low, can only reach 1 piece / hour, and is gradually eliminated due to low efficiency and high cost. At present, the method of spraying heat-insulating paint on the inner wall of the pipe mold is widely used at home and abroad to produce large-diameter ball pipes, and the production efficiency of different specifications is 1-3...

AI Technical Summary

Problems solved by technology

However, in recent years, with the continuous start of large-scale water delivery projects in China, the demand for large-diameter tubes has also increased rapidly. The existing production technology can no longer meet the needs of the market. Production efficiency to meet market demand

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