A micro-alloyed high-strength gray iron casting and its melting method

Abstract

The invention provides a microalloying high-strength gray pig iron piece and a smelting method thereof and relates to the field of metal casting. The gray pig iron piece comprises, by weight percent, 2.92%-3.48% of C, 1.52%-2.36% of Si, 0.22%-0.78% of Mn, 0.15%-0.5% of Cr, 0.3%-0.78% of Cu, 0.011%-0.098% of Nb, 0.02%-0.1% of V, 0.015%-0.025% of Ti and the balance iron and other traces of unavoidable impurities. A casting piece base body is intensified through microalloying, the intensity and the rigidity of the casting piece are improved, a high-efficiency nucleating agent is added, graphite form, hardness and texture uniformity can be effectively improved, the sensibility is reduced, the mechanical performance of the gray pig iron piece is improved, by adopting the in-mold inoculation manner, the utilization rate of the nucleating agent can be improved, the inoculation effect is improved, and the cost is reduced.

Description

technical field [0001] The invention relates to the field of metal casting, in particular to a micro-alloyed high-strength gray iron casting and a melting method thereof. Background technique [0002] As a traditional metal material, gray cast iron occupies an important position in foundry production. Although the proportion of gray cast iron in the world's total cast iron production has declined in recent years, statistics show that gray cast iron still occupies an important position in iron castings. At present, under the situation of energy saving and consumption reduction and automobile lightweight on a global scale, gray cast iron materials can still be widely used, which is closely related to its good casting formability, high strength, wear reduction, shock absorption and low cost. Inseparable. [0003] At present, the main gap between my country and foreign countries in the research and production technology of high-strength gray cast iron is that the strength of ca...

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Problems solved by technology

[0003] At present, the main gap between my country and foreign countries in the research and production technology of high-strength gray cast iron is that the strength of castings is low. The castings produced by the same chemical composition of molten iron have a strength 1-2 grades lower than that of foreign grades; the casting process is backward, and the wall thickness of castings is large. , heavy weight, such as machine tool castings are more than 10% heavier than foreign ones, and engine cylinders are more than 30% heavier than foreign ones; automobile plates or engine cylinders made of castings have poor wear resistance, low life, high cross-section sensitivity, and low processing performance. Difference

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