A method of improving the service life and performance of the roller body by using high-energy supersonic spraying technology

Abstract

The invention belongs to the technical field of high-energy supersonic thermal spraying of surface engineering, and in particular relates to a method for improving the service life and performance of a roller body by utilizing the high-energy supersonic thermal spraying technology. The invention adopts high-energy supersonic spraying technology, inserts inert gas into the supersonic powder feeding system, and uses the high-pressure inert gas flowing in with the powder to heat and expand in the combustion chamber of the supersonic spraying system to directly drive tungsten carbide powder particles into high-speed and high-energy Particles, high-speed and high-energy particles are directly embedded in the roller base, and the roller body does not need to be sandblasted before spraying. The high-energy powder particles form a tungsten carbide coating on the surface of the roller body. The tungsten carbide coating has high hardness, ultra-low porosity, and low surface area. With the characteristics of roughness and low grinding allowance, the precipitates of the film are not easy to adhere during the casting and cooling process of the roll surface, and the friction coefficient of the working surface of the roll body remains constant during long-term use, which can significantly improve the wear resistance of the roll surface and roll life.

Description

technical field [0001] The invention belongs to the technical field of high-energy supersonic thermal spraying of surface engineering, and in particular relates to a method for improving the service life and performance of a roller body by utilizing the high-energy supersonic thermal spraying technology. Background technique [0002] Cast film (Cast film) is a kind of non-stretched, non-oriented flat extrusion film produced by melt casting and quenching. Compared with blown film, it is characterized by fast production speed, high output, high film transparency and gloss. Good resistance, good thickness uniformity, and excellent balance of isotropic properties. At the same time, because it is a flat extrusion film, subsequent processes such as printing and compounding are extremely convenient. After surface treatment, the cast film can be used for compounding, color printing, aluminum plating, etc., and is widely used in textiles, food, daily necessities, pesticides and pharm...

AI Technical Summary

Problems solved by technology

[0004] With the progress of the times, the development of packaging machinery is advancing by leaps and bounds, and new technologies and new equipment are constantly emerging. Correspondingly, the casting machine has also achieved synchronous development. Therefore, the wear resistance and surface friction of the main cooling roll of the casting machine Higher and higher requirements have been put forward for the stability of the casting and the adhesion performance of the casting precipitate. However, the heat conduction efficiency of the chrome plating is low due to the use of electroplating or conventional supersonic spraying technology for the main cooling roller of the existing casting machine. , low hardness, and poor wear resistance; while the tungsten carbide coating sprayed by ordinary supersonic flame spraying technology has low powder particle energy, the porosity of the coating after spraying is generally between 0.6% and 1%, and the coating is not dense enough , easy to adhere to cast precipitates and affect the quality of the film; if adding large-particle spherical powder to the powder to impact and tamp the coating to reduce the porosity of the coating, on the one hand, the large-particle powder that plays a role in tamping during the spraying process is rebounded and cannot be deposited on the roller. A coating is formed on the surface of the substrate, which causes waste of powder and affects the economy of spraying. At the same time, because the energy of powder particles has not increased, the porosity of the coating after spraying will still be 0.4%-0.5%, and it will still be easy to stick due to the insufficient density of the coating. Casting precipitates affect the quality of the film, and no matter what kind of conventional supersonic spraying, since the energy of the sprayed powder particles does not increase, the surface of the substrate must be roughened by sandblasting before spraying, so that the coating can obtain sufficient bonding strength. On the one hand, sandblasting roughening will bring about changes in the surface stress of the main cold roll of the tape casting machine, resulting in increased deformation of the roller. On the other hand, due to the coarser surface roughness formed after sandblasting Either will bring a substantial increase in the grinding allowance after spraying, resulting in a substantial increase in the thickness of the coating to be sprayed, affecting the spraying economy of the main chill roll of the casting machine

[0005] Therefore, no matter whether it is chrome plating or ordinary supersonic flame spraying or the method of adding large particle spherical powder impact compaction coating in supersonic flame spraying, it is difficult to meet the increasingly high requirements of tape casting equipment.