Preparation method of metal protective coating for inner wall surface of inner bore part

Abstract

The invention discloses a preparation method of a metal protective coating for the inner wall surface of an inner bore part and belongs to the technical field of surface engineering. The metal protective coating is mainly applied to perform protective treatment on the inner wall surface of a mechanical inner bore part. The preparation method comprises the following steps: the inner wall surface of the part is subjected to cleaning, presetting a powder / binder coating, drying, high-frequency induction heating cladding, cooling and the like, and then a high-frequency induction cladding coating is prepared on the inner wall surface. The metal protective coating is not only applicable to parts made of iron, cobalt and nickel, but also applicable to ti-based, aluminium-based, copper-based and other conductive inner bore metal parts. The metal protective coating prepared on the inner wall surface of the part has the following advantages: metallurgical bonding is formed between a matrix and the coating; a heat affected zone is narrow, and thermal damage and deformation are not caused for the matrix; a cladding coating and an interface texture are compact, a crystal grain is fine and small, and defects like holes, slag inclusion and cracks are avoided; different metals or alloy powder can be selected as coating materials for preparing a wearproof, antifriction or anticorrosion coating according to the actual working condition demands of the inner wall of the part.

Description

technical field [0001] The invention designs a method for preparing a metal protective coating on the inner wall surface of inner hole parts, which belongs to the field of surface engineering technology. The invention is mainly used for protective treatment of the inner wall surface of mechanical parts, and can be used for strengthening new parts and also for waste parts. repair and remanufacturing. Background technique [0002] Inner hole parts have a large quantity and a wide range. For example, hydraulic cylinders, friction couplers, oil and gas pipelines and other parts are widely used in industry. Due to wear or corrosion conditions, in the process of strengthening the inner wall surface of new inner hole parts, or repairing and remanufacturing the inner wall of failed parts, the preparation technology of inner wall surface coating of parts is the key to improving and restoring the quality and performance of parts. The essential. At present, the commonly used inner wa...

AI Technical Summary

Problems solved by technology

Among them, due to the limitation of the coating deposition principle, the thermal spraying technology only forms a mechanical bond between the substrate and the coating, and there are a large number of pores, micro-cracks and other defects inside the coating, and the coating is prone to peeling off and failure under harsh working conditions. When the diameter of the inner wall is less than 80mm, effective spraying cannot be carried out due to the limitation of the pore structure; the cladding coating prepared by laser cladding technology can form a metallurgical bond with the substrate, and the coating has no pores inside, but due to the heat input during laser cladding Large amount, it is easily affected by thermal stress to form cracks inside the coating, and it is also limited by the size of the inner wall like thermal spraying technology, which cannot effectively clad the narrow and small inner wall surface; electroplating hard chrome technology is the current hydraulic cylinder and other inner wall parts The most commonly used coating preparation technology on the inner wall surface, hard chromium coating has good corrosion resistance and wear resistance, high coating quality, but hexavalent chromium is toxic, the coating preparation process has a large negative impact on the environment, and the coating deposition efficiency Low, the thickness of the coating is usually less than 0.1mm; vapor deposition technology can also prepare thin film coatings with excellent performance on the inner wall surface, but the coating thickness is usually in the range of several microns to tens of microns, and it cannot be realized due to the size of the deposition equipment cavity Coating preparation for inner walls of large-sized parts

In summary, the currently commonly used surface coating preparation technology is not suitable for the rapid preparation of high-performance thick coatings for inner wall parts that fail to wear or corrode under harsh working conditions, and cannot realize cylindrical narrow and long coatings with inner wall diameters less than 80 mm and lengths between 200 mm and 1000 mm. , Strengthening or repairing inner hole parts with small inner wall diameter

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