Process for preparing ductile cast iron-based composite

Abstract

The invention discloses a process for preparing a ductile cast iron-based composite, which mainly comprises the following steps: weaving molybdenum nets with molybdenum wire, shearing the nets, and rolling a plurality of layers of molybdenum nets or overlapping the molybdenum nets to form a netty solid framework structure; manufacturing a casting mold according to the requirements of a manufacturing process, and pre-placing the molybdenum wire solid netty framework in the cavity of the casting mold; pouring smelted ductile cast iron into the casting mold and cooling and cleaning the ductile cast iron to obtain a molybdenum wire-ductile cast iron binary material prefabricated body; and placing the molybdenum wire-ductile cast iron binary material prefabricated body into a heat treatment furnace to heat the molybdenum wire-ductile cast iron binary material prefabricated body to a temperature at which carbides are formed and keeping the temperature to obtain the molybdenum carbide particle-reinforced ductile cast iron-based composite. The composite prepared by the method has the advantages that: the high-temperature wear resistance of a molybdenum carbide hard phase and the high toughness of the ductile cast iron are fully played; the regulation is convenient; the process is reliable; and the problems of incomplete reaction of the composite, the uneven particle distribution in the reinforced phase and the weak anti-pollution performance of the interface of the reinforced phase and the like are solved. The composite is widely used in mine, power, metallurgy, coal and building material wear-resistance fields and other wear-resistance fields.

Description

technical field [0001] The invention belongs to the technical field of metal-based composite materials, and in particular relates to a preparation process of nodular cast iron-based composite materials. Background technique [0002] Ductile iron is a commonly used metal material widely used in metallurgy, mining, electric power, construction, machinery, coal, automobiles and other industries. Due to its high carbon content, after inoculation and spheroidization, the carbon forms in the form of spherical or worm The shape of graphite is distributed in the structure, so that the ductile iron has better strength and toughness. However, due to the lack of hard phases such as carbides in ductile iron, its macroscopic hardness is only about HRC35, so ductile iron cannot resist the cutting and wear effect of abrasives on the surface of parts under wear conditions, which makes it difficult to apply ductile iron to wear On the equipment parts, it greatly limits its scope of use. ...

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Problems solved by technology

However, due to the lack of hard phases such as carbides in ductile iron, its macroscopic hardness is only about HRC35, so ductile iron cannot resist the cutting and wear effect of abrasives on the surface of parts under wear conditions, which makes it difficult to apply ductile iron to wear equipment parts, greatly limiting its scope of use

[0003] In terms of improving the wear resistance of ductile iron in production, by adding alloying elements or heat treatment to obtain structures such as bainite and martensite, the wear resistance can only be slightly improved, and ductile iron cannot be widely used in the field of wear; in recent years A composite preparation process of ceramic particle reinforcement has emerged, such as placing molybdenum carbide or molybdenum nitride particles on the bottom of the mold, and then pouring ductile iron, but the preparation process is difficult to control stably, and the distribution of reinforcement particles is uneven, and it is still difficult to obtain reinforcements Uniformly distributed overall wear-resistant ductile iron

There are also hard particles such as molybdenum carbide solidified with a binder, put into the mold, and then pour the molten metal to make the hard particles and the molten metal penetrate and fuse with each other. However, due to the decomposition of the binder at high temperature, a large amount of gas is generated. Lead to the formation of many pores inside the composite layer, the effect is not ideal

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