Analysis of temperature and stress field of hydraulic support guide sleeve remanufacturing

The guide sleeve is a key part to ensure the concentricity of the piston rod and cylinder of the hydraulic cyl⁃ inder，and to provide the support for the oil seal at the cylinder port. In order to save the repair cost and prolong the service life of the guide sleeve of hydraulic support，this paper investigates the remanufacturing and repairing technolo⁃ gies of the guide sleeve by using laser additive remanufacturing technology. Based on the numerical simulation method，the numerical model of transient thermal analysis for the laser additive remanufacturing repair of guide sleeve is established. The evolution law of temperature field and stress field at each node of cladding layer of guide sleeve under different laser energy densities is studied. The influence of laser energy density on temperature field，stress field and residual stress distribution is discussed. The processing parameters are optimized by process test，the Cu-8Sn-3Zn powder is used to repair the outer circumference of the wear failure guide sleeve，and the residual stress distribution at different nodes of the cladding layer is measured. The results show that under different laser energy densities，the temperature and stress evolution of each node in the cladding layer go through several reciprocating cy⁃ cles，and gradually tend to be stable at the end of the deposition process. With the increase of laser energy density，the temperature of cladding layer gradually increases，and the equivalent stress also increases，when the laser energy density is 31. 8 J / mm2 . The peak value of residual stress appears at the end of cladding layer， which is 278.54 MPa. The optimal laser energy density of 31.8 J / mm2 ，namely laser power P = 1 000 W，scanning speed vs = 10 mm / s，is verified by experiments. It is found that the appearance of cladding layer is good，no obvious cracks and other defects. The microstructure of the cladding layer is uniform and dense，without holes and inclusions of unmelted powder. The peak value of residual stress at the end of cladding layer is 212.89 MPa after cooling. However，due to the interaction of laser shock，powder action mechanism and other factors，the experimental results and numerical simulation results have errors， but the overall change trend is consistent， which has a certain engineering value and guiding significance. The study provides a reference for the quality control and process parameter optimization of laser assisted remanufacturing repair of guide sleeve.