A kind of nodular cast iron for cylinder liner and preparation method thereof

Abstract

The present invention relates to the technical field of cylinder liners, in particular to a ductile iron for cylinder liners and a preparation method thereof, wherein the ductile iron comprises the following chemical components: C: 3.4-4.3%; Si: 2.6-2.9%; Mn: 0.4-0.7%; P: <0.1%; Cr: <0.15%; S: <0.025%; Ni:0.2-0.5%; Mo:0.2-0.5%; Cu:0.4-0.9%; Mg:0.03-0.08% , the preparation method of the nodular cast iron comprises the following steps: smelting, spheroidizing and inoculating, and centrifugal casting; the material of the nodular cast iron alloy prepared by the present invention is a completely cast nodular cast iron, which does not need subsequent heat treatment, which reduces the manufacturing cost of the enterprise. cost. In addition, in the present invention, a medium-frequency induction furnace is used to smelt and prepare nodular cast iron alloys. In the structure of the electric furnace, an overturning induction structure, an anti-dripping structure and a furnace body protection structure are provided, which can effectively ensure safety during the smelting process, especially After the equipment is aging, it can play the role of early warning and emergency protection.

Description

technical field [0001] The invention relates to the technical field of cylinder liners, in particular to a ductile iron used for cylinder liners and a preparation method thereof. Background technique [0002] Engine main engine manufacturers put forward a series of strict requirements for supporting cylinder liner manufacturers to increase the engine horsepower under the condition that the cylinder liner bore diameter remains unchanged, so as to achieve lighter engine production, which can not only save production costs, but also save time. On the basis of increasing or reducing emissions, the engine horsepower is increased, which requires the cylinder liner to have excellent mechanical properties and high-quality inner hole mesh. [0003] At present, the cylinder liner is mostly made of gray cast iron, which cannot meet the requirements of customers with higher mechanical properties. [0004] At the same time, in the process of preparing the cylinder liner, the medium freq...

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Problems solved by technology

[0003] At present, the cylinder liner is mostly made of gray cast iron, which cannot meet the requirements of customers with high mechanical properties.

[0004] At the same time, during the preparation of cylinder liners, medium-frequency induction melting furnaces are generally used to smelt raw materials. However, the induction furnaces currently used are usually rotated and installed on a bracket. Rods and connection points, it is very easy to cause damage to the connection, affect the stability of the furnace body rotation, cause splashing during the discharge process, and even cause the furnace body to fall, and the high-temperature molten metal will cause serious damage to the furnace body and the induction coil. big damage

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