| As a key support equipment for coal mine comprehensive mining equipment,the reliable service of hydraulic supports is a prerequisite for ensuring long-term safe operation underground.In order to ensure mine safety and avoid unplanned shutdowns,regular inspections and inspections are often used to replace column cylinders with abnormal situations such as pressure relief and liquid leakage.The material cost of the cylinders accounts for 60%of the total cost,and the economy of replacing new cylinders is poor.Therefore,the maintenance and anti-corrosion of waste column cylinders to quickly restore them to use has become a key technology for improving quality and efficiency in coal mines.This article mainly studies the composite anti-corrosion and maintenance process of the outer cylinder body with a damage depth of 0.25 mm<h<3 mm for the inner hole of the cylinder body(hereinafter referred to as "out of tolerance repair"),to solve the problem of incomplete anti-corrosion of the inner surface of the outer cylinder body still existing in the repair of the outer cylinder body by enterprises using copper alloy surfacing technology(hereinafter referred to as "anti-corrosion problem”),as well as the two problems of insufficient hardness of copper alloy surfacing in the inner hole of the outer cylinder body(hereinafter referred to as "hardness problem").The main job responsibilities are as follows:Firstly,a comparative analysis of existing anti-corrosion technologies was conducted,taking into account practical engineering applications and development prospects.Combined with the actual structural characteristics of the oil cylinder,a composite process was determined.Clarify the research content:Firstly,adopt the composite anti-corrosion and maintenance process of "surfacing copper alloy+QPQ salt bath composite treatment technology" to solve the anti-corrosion problem;The second research content adopts the "laser cladding copper alloy+QPQ" composite anti-corrosion and maintenance process to solve the hardness problem.Then,by analyzing and exploring the application of the composite technology of "surfacing copper alloy+QPQ" in the outer cylinder body,the key research content is determined,which is the impact of QPQ treatment on the surfacing copper alloy layer.Weld copper alloy on 27SiMn substrate(commonly used material for oil cylinders)according to the process of copper alloy surfacing in the cylinder bore,and perform QPQ treatment to obtain experimental samples and carry out relevant experimental research.Compare and analyze the changes in surface morphology,internal structure,composition,corrosion resistance,and hardness of the copper alloy layer before and after QPQ treatment.We have developed a composite anti-corrosion and maintenance process of "surfacing copper alloy+QPQ" that is suitable for the current use of surfacing technology by enterprises to repair the outer cylinder body.Secondly,a numerical simulation model for laser cladding of copper alloy was established,and pre experiments were conducted to determine the range of simulation parameters.Through the analysis of simulation results,the influence of laser power and scanning speed on the melting depth was obtained,providing a basis for determining the parameters of laser cladding experiments.Before the laser cladding experiment,copper alloy powder was prepared for the experiment,and the relationship between scanning speed,powder feeding rate,powder feeding disc speed,and powder feeding amount was established through theoretical calculations and actual detection data.Conduct laser cladding experiments,measure and compare the size of the melt channel,calculate the dilution rate,conduct hardness testing,and find the optimal laser cladding process parameters.Develop a composite anti-corrosion and maintenance process of "laser cladding copper alloy+QPQ" to provide technical support for enterprises. |
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