High-strength gray cast iron and low Si-Al inoculation process thereof

Abstract

The invention discloses high-strength gray cast iron and a low Si-Al inoculation process thereof, and relates to the technical field of gray cast iron. The high-strength gray cast iron comprises the following components, in percentage by weight, 3.5-3.8% of C, 1.5-1.9% of Si, 0.01-0.09% of Ti, 1.1-1.33% of Mn, 0.4-0.6% of Cu, 0.63-0.92% of Cr, 0.63-0.92% of Zr, 0.63-0.92% of Ba, 0.17-0.73% of Ni, 1.12-2.21% of Zn, 0.012-0.021% of As, 70-120 ppm of N, 0.03-0.05% of Re, less than 0.12% of P, less than 0.03 of S, less than 20 ppm of Pb, and the balance Fe. Two grades of inoculation agents are added in liquid-state cast iron to form a lot of sub-microscopic cores to accelerate growth of eutectic cells in a liquid phase; when an eutectic solidification temperature is approached, fine graphite flakes are firstly formed in the core growth places, and the eutectic cells are grown; less heat can be released to the surrounding liquid phase due to formation of each eutectic cell; and more eutectic cells are formed, and the solidification speed of the cast iron is lower.

Description

technical field [0001] The invention belongs to the technical field of gray cast iron, in particular to high-strength gray cast iron and its low Si-Al inoculation process. Background technique [0002] Gray cast iron dominates the cast alloys. In recent years, with the improvement of casting quality requirements for machinery, metallurgy, textile and other industries, the demand for medium and high strength gray cast iron has increased sharply. After my country's accession to the WTO, it will become a major exporter of castings, and this demand will further increase. [0003] At present, there are two main methods for producing medium and high-strength gray cast iron in my country: one is to reduce the carbon content of the original molten iron and strengthen inoculation; the other is to add trace alloy elements. We know that gray cast iron has a higher carbon equivalent, especially a higher carbon content is a necessary condition to ensure that gray cast iron has excellen...

AI Technical Summary

Problems solved by technology

Each inoculation treatment method has its advantages, but also has certain limitations. So far, there is no treatment method that can adapt to various production conditions.