Wear-resistant coating and preparation method thereof, cutter ring of shield hob, shield hob and shield machine

Abstract

The invention provides a wear-resistant coating and a preparation method thereof, a cutter ring of a shield hob, a shield hob and a shield machine, including a first coating and a second coating sequentially connected; the first The coating is prepared from nickel-chromium-iron alloy; the second coating is prepared from the following components in parts by mass: 5-12 parts of diamond micropowder, 1-5 parts of calcium fluoride and 83-5 parts of nickel-based solder 94 parts; the first coating is used to connect with the substrate whose main raw material is iron or iron alloy. The wear-resistant coating provided by the present invention is composed of multi-pass, different and thinner coatings, and a nickel-chromium-iron alloy transition layer is added between the substrate and the nickel-based solder to inhibit the initiation and expansion of cracks , enhance the bonding strength between the coating and the substrate, and add diamond micropowder as the hard phase in the coating, which has the advantages of small thermal damage, uniform distribution of hard phase, and low cost, and effectively improves the shield hob cutter ring Excellent wear resistance and prolong the service life of the knife ring.

Description

technical field [0001] The invention relates to the field of engineering equipment surface treatment, in particular to a wear-resistant coating and a preparation method thereof, a cutter ring of a shield hob, a shield hob and a shield machine. Background technique [0002] The shield hob is a kind of shield machine tool, which plays the role of advancing "forward" during construction. The shield hob consists of a cutter ring and cutter teeth. The knife ring generally uses alloy steel as the base material, and the knife teeth are brazed or inlaid cemented carbide. The tungsten carbide cutter teeth play the role of rolling and cutting rock and soil, and the cutter ring supports and protects the tungsten carbide cutter teeth. Affected by random changes in soil conditions and groundwater pressure, with the continuous advancement of construction and the continuous rotation of the cutter head, the shield hob is subjected to continuous and changing forces such as extrusion, jacki...

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Problems solved by technology

[0004] However, the existing shield hob cutter ring coating has the following problems: the wear-resistant coating of the cutter ring is prepared by the surfacing welding method. Although a thicker coating can be prepared, the heat output of the surfacing welding is large, and the thermal stress after the surfacing welding is large , it is easy to generate cracks, and it is easy to expand into the base material and break the knife ring; the hard phase of the existing coating is mostly large-grained carbide or cemented carbide, and the coating is uneven, which is easy to produce local stress concentration and micro-cracks , causing the hard phase with large particles to be easily broken or falling off during the working process; the wear-resistant coating is prepared by the conventional brazing method, although the thermal stress is small, but the prepared coating is very thin, and the wear resistance of the knife ring is difficult to be effective Improvement; using laser cladding, high equipment investment and high coating cost

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