A kind of gray cast iron with high thermal conductivity and high strength and preparation method thereof

Abstract

The invention belongs to the technical field of preparation of iron and steel and particularly relates to high-thermal conductivity high-strength gray cast iron and a preparation method of the high-thermal conductivity high-strength gray cast iron. The gray cast iron comprises various elements of 3.3-3.8 wt% of C, 1.2-1.8 wt% of Si, 0.4-0.8 wt% of Mn, 0.1-0.5 wt% of Mo, 0.4-0.8 wt% of Cu, 0.05-0.15 wt% of Sn, 0.01-0.04 wt% of S, 0.004-0.02 wt% of Sr, less than 0.03 wt% of P, less than 0.5 wt% of Ni, and the balance of Fe and inevitable impurities. The gray cast iron is prepared through smelting, breeding and casting. The tensile strength of the provided gray cast iron is 280-350 MPa, the hardness is 210-240 HB, the heat conductivity coefficient is 50-60 W / (m.K), and the heat conductivity coefficient is obviously higher than that of the gray cast iron having the same tensile strength under the same test conditions.

Description

technical field [0001] The invention belongs to the technical field of iron and steel preparation, in particular to gray cast iron with high thermal conductivity and high strength and a preparation method thereof. Background technique [0002] Gray cast iron is a type of cast iron with a gray cross-section and carbon present mainly in the form of flake graphite. The structure of metal matrix plus flake graphite not only makes gray cast iron have good shock absorption and shock absorption performance, but also gives it good thermal conductivity. Such characteristics make gray cast iron widely used in structural parts under high / low cycle fatigue and thermomechanical fatigue conditions, such as steel ingot molds, automobile engine cylinder blocks, cylinder heads and brake discs, etc. [0003] With the development of the economy, the load requirements for structural parts are getting higher and higher, and the wall thickness is getting thinner and thinner for the sake of energ...

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Problems solved by technology

[0004] However, the tensile strength and thermal conductivity of gray cast iron are two properties that restrict each other, and the structure that is beneficial to the tensile strength is harmful to the thermal conductivity, and vice versa

The requirement for high tensile strength can be achieved by reducing carbon equivalent and adding alloy elements, but these methods not only reduce the filling and feeding performance of castings, but also increase the scrap rate, and also increase the whitening tendency of cast iron, reducing If the amount of eutectic graphite is reduced, the thermal conductivity will decrease; and in order to improve the thermal conductivity of gray cast iron, a high carbon equivalent must be used, which will lead to a decrease in the strength of cast iron

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