Production technology for ductile iron casting with high strength and high ductility

Abstract

The invention discloses a production technology for a ductile iron casting with high strength and high ductility. The production technology comprises the following steps: 1, adding 18-22 parts of steel scrap into an electric furnace for smelting, adding 58-62 parts of foundry returns, and finally, adding 0.5 part of a structure modifier and 18-22 parts of pig iron at the same time for smelting, so as to obtain raw molten iron; 2, adding a nodulizing agent into a nodulizing chamber of a nodulizing ladle, and coating the nodulizing agent with a nucleating agent, covering the nucleating agent with a silicon steel sheet, and finally, adding the structure modifier into the nodulizing ladle; 3, enabling the raw molten iron of which the temperature is controlled to be 1460-1480 DEG C in the electric furnace to react in the nodulizing ladle, so as to obtain final molten iron; 4, pouring the final molten iron for casting, and cooling, so as to obtain the ductile iron casting. According to the invention, the burning loss of crystal cores in molten iron can be prevented, the quality of molten iron is improved, and the ductility and strength can be greatly improved.

Description

technical field [0001] The invention relates to a production process of ductile iron castings, in particular to a production process of high-strength and high-elongation ductile iron castings. Background technique [0002] Ductile cast iron is a kind of cast iron in which the graphite in cast iron is spherical. The graphite is formed into a spherical shape through spheroidizing treatment. This spherical graphite can reduce the stress concentration and reduce the cracking of the matrix. Due to the high strength, plasticity and toughness of ductile iron, the fatigue strength is close to that of medium carbon steel, the wear resistance is better than that of non-alloy steel, the cutting performance is comparable to that of gray cast iron, and the manufacturing cost is low, it has been widely used. . [0003] In the production process of nodular cast iron, molten iron can be formed after melting raw materials with different ratios. The quality of molten iron and the effect of s...

AI Technical Summary

Problems solved by technology

At present, when conventional manufacturers produce QT600 materials, the general elongation rate can only reach 5-7. Although it has reached the national standard that the elongation rate exceeds 3, it is still in a low performance.