Thrust pad repairing method based on laser cladding process

Abstract

The invention aims at providing a thrust pad repairing method based on a laser cladding process. The deformation amount in the thrust pad repairing process is effectively controlled, the problems of hole shrinkage and shelling of a babbitt metal layer are thoroughly solved, the design size of a thrust pad is recovered, the use performance of the thrust pad is improved, the service life of the thrust pad is prolonged, and extremely high economical efficiency is achieved. The thrust pad repairing method comprises the following steps: removing an original babbitt metal layer of the thrust pad, preparing the babbitt metal layer on the surface of a steel billet through laser cladding, carrying out ultrasonic flaw detection, milling, carrying out dye penetrant inspection and grinding. According to the method, the thrust pad which fails in service is remanufactured, and the use performance of the thrust pad is recovered and improved through a new additive manufacturing method. Compared with pouring and oxyacetylene welding processes, the manufacturing process of the babbitt metal layer is greatly simplified, the steel billet preheating and tinning processes are omitted, and the quality of the babbitt metal layer, the combination condition of the babbitt metal layer and the steel billet, the deformation amount of the steel billet and the labor environment are effectively improved.

Description

technical field [0001] The invention relates to the field of bearings, in particular to a thrust pad repair method based on a laser cladding process. Background technique [0002] Babbitt is named after the invention of American Babbitt. Since its inception, babbitt has been widely recognized as a material with excellent performance because of its good wear resistance, thermal conductivity and special structure. It is beneficial to reduce friction, so it is widely used as a bearing material. [0003] The turbine thrust pad, which is different from the traditional bearing pad, is a plane thrust bearing that bears the weight and axial water thrust of the rotating part of the entire unit. Long-term use will cause defects such as scratches, wear, and shrinkage holes to be exposed, affecting the normal operation of the unit. operation, must be replaced in time. At present, there is no effective repair method for the failed replacement of the thrust pad. The traditional babbitt ...

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Problems solved by technology

[0003] The thrust pad of the hydraulic turbine is different from the traditional bearing pad. It is a plane thrust bearing, which bears the weight of the rotating part of the entire unit and the axial water thrust. After long-term use, defects such as scratches, wear, and shrinkage holes will be exposed, which will affect the normal operation of the unit. operation, must be replaced in time

At present, there is no effective repair method for the thrust tiles that have failed to be replaced. The traditional Babbitt casting process is complicated, and this method has the following defects:

[0004] 1. The pouring process includes billet preheating, tinning, babbitt melting, mold making preparation, babbitt pouring, cooling, defect repair, etc. The process is complicated

[0005] 2. The process of hanging tin in the pouring process is the key to the combination of Babbitt alloy and steel billet. It is not easy to control. Improper control can easily lead to shelling of the Babbitt alloy layer, and the tinning is through the chemical reaction between tin and the surface of the billet. In this case, the bonding method is chemical bonding, the bonding layer is thin, and the bonding force is not reliable.

[0006] 3. The pouring of Babbitt alloy requires a long period of solidification and cooling process, which is prone to shrinkage and shrinkage defects

[0007] 4. In the babbitt alloy pouring process, the heat input is large, the thermal deformation of the billet is large, the flatness of the billet and the babbitt alloy layer is poor, and the amount of machine addition is large

If the temperature is too low, a good tinning layer cannot be formed; if the temperature is too high, the steel bottom of the thrust tile is easily oxidized, and the tinning is not easy to bond, resulting in the Babbitt alloy being unable to be effectively combined with the tile bottom, resulting in shelling defects, and the quality is difficult to obtain. ensure

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