Method for producing high-strength cast iron by using waste iron and steel

Abstract

The invention discloses a method for producing high-strength cast iron by using waste iron and steel. The method comprises the following steps of: weighing 68 to 72 weight percent of waste iron, 28 to 32 weight percent of waste steel and 1.4 to 1.6 weight percent of manganese iron; smelting metallic furnace charges, namely the waste iron and the waste steel at a high level by using two rows of cupolas, wherein the base coke blowing strength is about 100m<3> / m<2>.min, and the tapping temperature is controlled to be more than and equal to 1,450 DEG C, coke with low ash content and porosity and 85 percent of fixed carbon is adopted, so that the molten iron is always in a high temperature state and fully recarburized; and performing inoculation treatment on the molten iron, and when the molten iron is discharged, adding spare silicon iron into an iron charging groove. The cast iron is high in strength and has a fine structure, and the graphite content is low; and the casting performance and machining performance of the cast iron are high, the manufacturing cost is low, and harmful hereditary does not exist.

Description

technical field [0001] The invention relates to a casting method, in particular to a method for producing high-strength cast iron from scrap iron and scrap steel. Background technique [0002] Production of high-strength cast iron with new iron, including scrap iron and scrap steel, furnace charge ratio: scrap steel 30%, recycled waste cast iron 35%, new iron 35% (according to "Casting Engineer's Handbook"), this ratio is low in strength and difficult to control. Hot metal tends to be white, prone to shrinkage defects, prone to cast iron hereditary defects, and high production costs. [0003] The applicant is a professional manufacturer of machine tool castings. Machine tool castings require smooth surfaces, clear outlines, and certain strength and hardness properties. In the production practice of casting machine tool castings, it is often encountered that the new iron in the charge used is often hereditary, which changes various properties of castings and increases casti...

AI Technical Summary

Problems solved by technology

[0006] 3. Some machine tool guide rails produced by the applicant must be subjected to high-frequency quenching. Due to the genetic effect of some neonatal iron, the hardness of the guide rails cannot meet the requirements after quenching.

[0009] A large amount of returned iron needs to be purchased from the market. This type of returned iron comes from various scrapped mechanical parts in different periods. In a limited proportion of ingredients, this inheritance does not reach the critical value of harmful effects, and its casting defects will not show up

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