Damage repair method for marine steam turbine rotor

Abstract

The invention relates to a damage repair method for a marine steam turbine rotor. When the damage repair method repairs damage defects such as corrosion pits and erosion pits with large depths (the depths are at least 0.3mm) in a steam seal shaft neck and an impeller disk surface of the marine steam turbine rotor, firstly a resistance heat energy micro arc surfacing technology is adopted for welding repair for the damage defects; after the welded steam turbine rotor is reconditioned, a solid laser prepares a wear-resisting corrosion protection coating on the surface of the steam turbine rotor by using a laser cladding technology, and then the required sizes of the steam seal shaft neck and the impeller disk surface of the steam turbine rotor are achieved after processing. As the functional coating prepared by using the resistance heat energy micro arc surfacing technology and the laser cladding technology is adopted, the appearance is uniform, the structure is compact, and a cladding layer and a base material form metallurgical bonding; moreover, the dilution rate is low, and the problems that the steam seal shaft neck of the steam turbine rotor is easy to wear and the impeller disk surface is easily eroded by steam are effectively solved.

Description

technical field [0001] The invention belongs to the technical field of surface repair engineering, and in particular relates to a method for repairing surface damage of a marine steam turbine rotor, which can prolong its service life in all directions. Background technique [0002] In recent years, in the process of maintenance and support of new equipment, it has been found that corrosion and wear on the surface of the rotor seal journal of marine steam turbines and erosion damage on the impeller disk surface are common, which has become a difficult problem in maintenance and support. For example, the rotors of marine steam turbine auxiliary machines, such as the rotors of condensate booster pumps, feed water pumps and blower turbines, the moving surface of the journal of the steam seal is affected by factors such as wear, corrosion, and vibration during service. It is prone to damage and has become a hot and difficult problem in maintenance and support work. The steam tur...

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Problems solved by technology

However, it has been tested by operation practice that the electroplated hard chromium layer is difficult to meet the requirements of this working condition

In the prior art, there are also many research results on steam turbine rotor steam seal journal repair using laser cladding technology. The invention patent application with application number 201210351284.X "Laser cladding repair process of cross shaft", the invention patent application with application number 201310310313958.1 "alloy powder and repair method for laser cladding repair of high-speed rotating mechanical shaft", etc., the above repair scheme The laser cladding technology adopted does not propose how to solve the problem of deep corrosion pits in the steam turbine rotor seal journal. At the same time, the temperature change of the coating prepared by the cladding equipment is small, and it is easy to generate temperature accumulation. In order to avoid stress cracks, the thickness of the cladding layer will be limited, the cladding quality is unstable, and the efficiency is low

[0004] Similarly, during the operation of the steam turbine rotors of marine lubricating oil pumps and fuel pumps, the upper and lower impeller surfaces and balance holes of the impellers are eroded by high-pressure saturated steam, resulting in scattered and stacked erosion pits, resulting in rotor balance damage , the vibration of the unit is intensified and the stability is reduced, which has also become the "bottleneck" of maintenance support

At present, the local damage of the impeller disk surface of the steam turbine rotor can be repaired by welding repair method, but the local stress will be generated during the welding repair process, and deformation will occur in severe cases, especially for the rotor with large-scale damage to the impeller disk surface, it can only be replaced with a new one. , there is no report on impeller disk repair using laser cladding technology

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