Surface treatment process for hydraulic support intermediate cylinder, plunger and piston rod used under coalmine well

Abstract

The invention discloses a surface treatment process for a hydraulic support intermediate cylinder, a plunger and a piston rod used under a coalmine well. The surface treatment process comprises a laser cladding process and a chromium plating process which are sequentially carried out on the surface of a workpiece, a pretreatment process is joined between the laser cladding process and the chromium plating process, and the pretreatment process comprises the steps of ultrasonic oil removal, washing, cathode electrochemical oil removal, first hot washing, acid leaching, washing, cathode activation and second hot washing. The surface treatment process disclosed by the invention has the advantages that the laser cladding process and the electroplating process are combined, the corrosion resistance of the surface treated layer of the workpiece is observably improved, and the hardness and the abrasive resistance of the surface-treated layer are also observably improved. Because a base body and outer aggressive media are isolated by a stainless steel layer directly cladded on the surface of the workpiece, a good preservative effect is obtained; and the chrome is plated on a laser cladding layer, the requirements on the hardness and the abrasive resistance of the workpiece are satisfied, and the corrosion resistance of the workpiece can be further improved by adjusting the kind of the chromium plating layer.

Description

technical field [0001] The invention relates to the surface treatment of some components of a hydraulic support, in particular to a surface treatment process for a cylinder, a live column and a piston rod of a hydraulic support used in underground mines. Background technique [0002] Columns and jacks are important components of the hydraulic support, and are the key support for realizing various functions of the hydraulic support. Due to the harsh downhole environmental conditions (expressed as an acid-base environment and containing Cl - , SO 4 2- Plasma and SO 2 、H 2 S and other corrosive gases), in order to reduce the failure of columns and jacks caused by corrosion, wear, foreign object impact, etc., and prolong the service life of columns and jacks, the cylinder in the column, the live column and the piston rod of the jack are treated for surface protection. important. At present, the commonly used surface treatment process is electroplating copper-tin alloy ...

AI Technical Summary

Problems solved by technology

At present, the commonly used surface treatment process is electroplating copper-tin alloy + hard chrome or electroplating milky chrome + hard chrome. The total thickness of the coating ranges from 0.05 to 0.09mm. Avoid corrosion of the substrate, and in view of the defects of the coating itself (pores, cracks) and the limitation of the coating thickness, the service life of the column and the jack in the well is usually only about two years, and the service life will be shorter if the environment is extremely harsh

If laser cladding technology is used to clad a layer of stainless steel on the surface of the middle cylinder, live cylinder and piston rod, it can solve the anti-corrosion problem of the middle cylinder, live cylinder and piston rod, and greatly improve their service life. The hardness of the layer is low (about HV150-400), the wear resistance is poor, and it is easy to produce scratches and bumps under the impact of foreign objects, which seriously affects the sealing and stability of the hydraulic system

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