A sand-coated iron mold process for the production of driving wheel steel castings

Abstract

The invention discloses an iron mold sand-coating process for the production of driving wheel steel castings, which comprises the following steps: the first step, molding; the second step, spraying; the third step, box closing; the fourth step, pouring preparation The fifth step is smelting and pouring; the sixth step is heat treatment; the iron mold sand coating process for the production of driving wheel steel castings of the present invention utilizes the high dimensional accuracy, high production efficiency, and low sand iron of the iron mold sand coating process. ratio, low pollution, low solid discharge and other excellent features, the production of driving wheel castings; the material of the low-alloy steel driving wheel manufactured by the iron mold sand-coated process of the present invention is SCSiMn2H, and the technical requirements are tensile strength > 686Mpa, yield strength ﹥420Mpa, impact toughness ﹥27J / cm²; through the chilling effect of sand-coated iron molds, the steel castings can obtain a matrix structure with dense structure and fine grains, so that the steel castings can obtain high tensile strength, high yield ratio, Excellent quality casting with high impact toughness.

Description

technical field [0001] The invention relates to a sand-coating technology for iron molds, in particular to a sand-coating technology for iron molds used in the production of steel castings for driving wheels, and belongs to the technical field of sand-coating iron molds. Background technique [0002] As our country enters the era of industrialization, in order to protect the health of the people, the country has continuously increased its efforts to protect the environment, and the management of "three wastes" has become more and more strict. The traditional cast steel production process has seriously affected the health of the people, and Cause serious pollution to the environment. For decades, the production of large and medium-sized steel castings in my country mostly adopts the traditional water glass sand molding process. Production of steel parts. However, due to the poor collapsibility of water glass sand and the low reuse rate of old sand, the shortcomings of the ol...

AI Technical Summary

Problems solved by technology

However, due to the poor collapsibility of water glass sand and the low reuse rate of old sand, the shortcomings of the old sand have become more and more serious. It is unimaginable, so finding an alternative process for the production of steel castings is a major problem that has plagued foundry workers in recent years

[0003] Through the efforts of foundry workers, in the 1980s, fat-hardened water glass was used instead of traditional inorganic water glass sand to produce steel castings, and the collapsibility was improved, but the recycling rate of old sand was only increased from 20% to 40%. The discharge of a large amount of waste sand is still a major problem hindering its widespread use in the production of steel castings. The key is that the serious harm of caustic soda in waste sand to the environment has not been completely improved

[0004] At the end of the last century, the alkali phenolic resin sand process was used in the production of steel castings, which greatly reduced solid emissions, but because the phenolic resin produced a large amount of sulfur dioxide and nitrogen dioxide after combustion, the air pollution was rampant; and accompanied by Formaldehyde and methane cause health hazards to the human body, which is one of the factors that cannot be widely used; secondly, the regeneration of phenolic resin is very difficult. Application in steel production

[0005] In recent years, foundry workers have been trying to make breakthroughs in the field of coated sand, but for large steel castings, due to the inherent characteristics of coated sand, there are several irreconcilable contradictions in the production of steel castings: 1. The large amount of gas generated by the coated sand and the poor exhaust capacity of the iron mold; 2. The low refractoriness of the organic binder of the coated sand and the high pouring temperature of the cast steel; 3. The high shrinkage of the cast steel and the iron mold Low yield of the mold; 4. Riser setting at non-hot joints and strong feeding of steel castings; 5. Reducing multiple runners at flow hot joints and less runners required for cast steel shrinkage; 6. Heating risers 7. The increase of the static pressure head and the limitation of the height of the iron mold covered with sand, the above contradictions have always been difficult problems that many foundry workers cannot solve

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