Production process of QT500-12 spheroidal graphite iron casting

Abstract

The invention discloses a production process of a QT500-12 spheroidal graphite iron casting. The production process comprises the following steps: A, raw material selection: selecting 60-80 parts of scrap steel, 20-40 parts of scrap returns, 2.5-3.5 parts of a carburant, 0.4-1.0 part of 75# ferrosilicon, 0.3-0.6 part of copper, 1-1.2 parts of a spheroidizing agent, 0.8-1.2 parts of a 75# ferrosilicon inoculant and 0.2-0.4 part of a silicon-strontium inoculant; B, weighing; C, smelting; D, spheroidizing; E, secondary inoculation; and F, pouring. The overall performances of the QT500-12 spheroidal graphite iron casting produced by using the production process are improved, and the tensile strength is larger than or equal to 500Mpa on the premise that the elongation percentage is larger than or equal to 12%; the consistency of a matrix structure of the spheroidal graphite iron casting is also realized, and the local function of the spheroidal graphite iron casting is prevented from being deteriorated; and the weight of the spheroidal graphite iron casting is reduced on the premise that the elongation percentage and tensile strength indexes of the spheroidal graphite iron casting reach standards, so that the lightweight of the spheroidal graphite iron casting is realized.

Description

technical field [0001] The invention belongs to a production process of ductile iron castings, in particular to a production process of QT500-12 ductile iron castings. Background technique [0002] Ductile iron is obtained through spheroidization and inoculation treatment to obtain spherical graphite, which effectively improves the mechanical properties of ductile iron castings, especially improves the plasticity and toughness of ductile iron castings, thereby obtaining higher strength than carbon steel, and its comprehensive performance is close to that of Steel is widely used to cast parts with complex stress, high strength, toughness and wear resistance. At present, the ductile iron castings produced in the market are generally produced with pig iron as the main raw material. Due to the genetic effect of metal, the ductile iron castings inherit the shortcomings of the thick graphite of pig iron. The graphite balls are thick and not very round, resulting in the cutting of ...

AI Technical Summary

Problems solved by technology

At present, the ductile iron castings produced in the market are generally produced with pig iron as the main raw material. Due to the genetic effect of metal, the ductile iron castings inherit the shortcomings of the thick graphite of pig iron. The graphite balls are thick and not very round, resulting in the cutting of the metal matrix. The effect is obvious, which limits the further improvement of its comprehensive performance

In addition, manganese elements will segregate during the solidification process of ductile iron castings, which will lead to the deterioration of the local function of ductile iron castings. , the manganese element is enriched locally, and the spheroidizing effect of the enriched part deteriorates

At the same time, with the development of society, more and more attention is paid to environmental protection and energy. The country is actively promoting the lightweight of ductile iron castings, which is restricted by the existing production process of ductile iron castings, which limits the implementation of lightweight ductile iron castings.

Images