Method for producing malleable iron pipe by using reclaiming waste

Abstract

The invention relates to a method for producing a malleable iron pipe by using reclaiming waste. The method is characterized in that a medium frequency furnace smelting process is adopted, foundry pig iron with waste machine iron, and raw materials include, by weight, 45-55 parts of foundry returns, 10-30 parts of waste rolled steel, 20-35 parts of the machine iron, 0.6-1 part of a carburetant, 0.25-0.5 part of ferrosilicon and 0-10 parts of malleable cast iron chippings. According to the method, the raw material structure and the matching process are optimized, the matrix structure of a cast workblank piece is improved, the product performance is stabilized, the phenomenon of casting grey pieces is reduced, and the rejection rate of cast products is reduced.

Description

technical field [0001] The invention relates to a batching method, in particular to a method for producing malleable cast iron pipe fittings by using recycled waste materials, and belongs to the technical field of metal casting. Background technique [0002] In foundry production enterprises, the technological process for the production of malleable iron pipe fittings mainly includes mold preparation, casting metal melting and pouring, casting processing and inspection procedures. At present, in the melting and pouring process of cast metal, cast pig iron and scrap steel are mostly used as the main raw materials, and auxiliary materials are added according to a certain proportion, and cupola or electric furnace is used for smelting. After chemical annealing treatment, a high-strength cast iron is obtained, which has high strength, plasticity and impact toughness. [0003] In the casting metal melting and pouring process for the production of malleable cast iron pipe fitting...

AI Technical Summary

Problems solved by technology

[0003] In the casting metal melting and pouring process for the production of malleable cast iron pipe fittings, the ratio of raw materials and the melting process are the main factors affecting product performance. The existing batching method with casting pig iron and scrap steel as the main raw material has problems with unstable performance of castings, It is easy to have the problem of casting gray parts (casting gray parts, that is, graphite, gray or mottled state in the fracture of the casting before annealing, and the performance is greatly reduced after annealing). More than one thousandth, in order to reduce the product rejection rate and eliminate the gray hole phenomenon of castings, the method of adding iron bismuth is generally used, which has caused an increase in production costs.