Steam Turbine Repair It is a very important work in laser processing technology. During the working process of the steam turbine, it is inevitable that some failures will occur. For example, how to repair the worn bearing bush of a steam turbine. Learn how to repair it below.

The bearing bush is the main component of the bearing, which is very lubricated and mostly composed of wear-resistant materials such as bronze and anti-friction alloys. The bearing bush is one of the key components of the steam turbine, and it has the effect of supporting the steam turbine working at high speed.

So how does the steam turbine scrape the bearing bush? Methods as below:

During the welding correction process of the bearing bush, the bearing shell shell is exposed at the repaired welding part, and it is necessary to carry out the tinning treatment first.

First, place the cleaned bearing bush horizontally, apply 30% zinc chloride solution on the surface coating layer to be corrected, and evenly heat the bearing bush to about 70°C with an oxygen-acetylene flame, then coat and weld pure tin to the bearing bush shell and damage the bearing bush On the outside, the thickness of the welding layer is 0.5mm-lmm, and then the alloy surfacing welding is carried out. The model is H01-6 welding torch, No. 1 nozzle, and the neutral flame is selected, so that the flame has 3 distinct areas; use flat welding Method, make the flame interval between the bearing bushes about 80mm, heat the bearing bushes evenly to about 300C, hold the alloy welding wire above the area to be welded, make the top of the white flame core of the flame and the welding surface at a 450° angle, adhere to the interval of about 5mm, and the welding torch and welding wire The zigzag swinging action melts the welding wire to form a welding bead. After the welding bead covers the surface of the area to be corrected at the bottom end, the first welding layer is formed. To ensure the quality of the welding bead, it is necessary to remelt the welding bead of each layer. The heating direction is opposite to the welding direction of the original bead to obtain a smooth and smooth surface of the bead. At the same time, the molten alloy is stirred with red copper wire, so that the pores and slag inclusions float up.

When welding, it is necessary to effectively control the welding temperature to avoid the formation of tin evaporation due to excessive temperature, which affects the composition of babbitt and melts the babbitt body of the bearing bush. Immediately after completion, apply 30% zinc chloride solution and remove residues and oxides. Use the same method to apply other welding layers. The final welding layer should be 1-2mm higher than the bearing bush, and pay attention to the junction between the weld bead and the original bearing bush. Defects such as undercut and lack of fusion should not be produced.

Post-weld trimming:

The first step: lathe processing, after pouring and forming, according to the size data of the motor rotor shaft provided by the manufacturer, the bearing bush is processed to a certain size according to the specification (the amount of scraping is 0.3).

Step 2: Rough scraping Use a rough scraper to remove a lot of the part of the welding layer higher than the bearing bush.

The third step: semi-fine scraping Use a fine scraper to remove the residue after rough scraping.

The fourth step: profiling Use metallographic sandpaper to profiling the alloy surface of the bearing bush to the mirror surface, and scrub it with clean cotton yarn.

The inspection is to inspect the corrected bearing bush by means of color flaw detection, and the inspection result is qualified if there are no cracks and defects.