Precision gear shaft bearing position laser repair method for eliminating axial stress

Abstract

The invention discloses a precision gear shaft bearing position laser repair method for eliminating axial stress, and belongs to the technical field of metal surface engineering. The repair method ischaracterized in that a bearing position is subjected to laser cladding by opposite spiral melting channels. The specific method comprises the steps as follows: grinding off a fatigue wear layer on the surface of the bearing position of a precision gear shaft; cleaning the grinding surface with absolute ethyl alcohol; preparing alloy powder; and clamping the precision gear shaft on a numerical control laser processing machine tool, scanning alloy powder delivered in place by gravity feeding by a fiber laser, and performing laser cladding on the precision gear shaft. The repair method eliminates axial stress in laser cladding repair of the precision gear shaft, prevents hidden danger of probable cracks of the bearing position due to axial stress when the precision gear shaft runs at high frequency and high speed in the future, and long-term safe and stable operation of the repaired precision gear shaft is ensured.

Description

technical field [0001] The invention relates to the technical field of metal surface engineering, in particular to a laser repair method for a precision gear shaft bearing position of a blast furnace supercharger for eliminating axial stress. Background technique [0002] The supercharger is the key equipment in the blast furnace, which undertakes the function of compressing air and blowing hot air to the blast furnace. In use, the supercharger compresses the air at high speed to increase the temperature of the air. The supercharged air is heated by a gas furnace to reach a high temperature and high pressure state, and then is blown into the blast furnace to promote the reduction reaction of iron ore and coke to generate molten iron. . [0003] As the core equipment of the blast furnace, the safe and stable operation of the supercharger is directly related to the casting rate and safe operation of the blast furnace. The speed of the precision gear shaft, the core component...

AI Technical Summary

Problems solved by technology

The speed of the precision gear shaft, the core component of the supercharger, reaches above 6000r / min. Due to the high-speed rotation of the precision gear shaft, the dimensional deviation in each direction is required to be less than 0.02mm, and internal stress is not allowed, otherwise fatigue cracks will easily occur, resulting in The precision gear shaft is damaged and the blast furnace is shut down; the bearing position of the precision gear shaft with fatigue wear cannot be repaired by traditional arc welding, plasma surfacing and other processes, because they all have problems such as large thermal deformation and large residual stress after welding, resulting in The gear shaft will be scrapped due to excessive dimensional deviation and internal stress

[0004] In recent years, the repair of common precision instruments adopts the laser cladding process, which is characterized in that a good cladding layer with low dilution rate can be obtained through the design of the alloy composition of the cladding layer and the adjustment of the laser process parameters, and the cladding layer The composition and dilution are controllable. By adjusting the process parameters, a cladding layer with a relatively wide thickness range can be obtained. The thickness is 0.2~2.0nm, with less material consumption and high cost performance; but the laser cladding process is equivalent to a small casting process, the characteristics of rapid melting and rapid solidification, so that there is a large residual stress in the cladding layer, the workpiece will be deformed, and even cracks will appear, especially the axial stress. Due to the axial stress, there may be hidden dangers of cracks in the bearing position