Anti-cavitation vane for steam turbine and method of forming same

Abstract

The invention discloses a steam turbine anti-cavitation blade and a forming method thereof. The steam turbine anti-cavitation blade is obtained by forming alloy material by laser on a forming base, single forming, a plurality of overlapping, and multilayer piling. The blade comprises an easy cavitating part of air intake side, a not easy cavitating part, and a transition region therebetween, the laser forming of the easy cavitating part of air intake side adopts anti-cavitation alloy powder; the laser forming of the not easy cavitating part adopts stainless steel powder; and the laser forming of the transition region adopts the mixed powder of the anti-cavitation alloy powder and the stainless steel powder. The steam turbine anti-cavitation blade of the invention has high intensity and hardness at blade air intake side, and high anti-cavitation performance, and the not easy cavitating part (such as the root part) of the blade has excellent toughness, which is beneficial to resist torsional stress fatigue. The forming method by laser of the invention greatly shortens the blade manufacturing time, saves the consumption of expensive anti-cavitation powder, and is more economic in forming.

Description

(1) Technical field [0001] The invention relates to an anti-cavitation blade of a steam turbine and a forming method thereof, belonging to the technical field of special processing. (2) Background technology [0002] Steam turbine blades are extremely important components in thermal power plants. After the high-temperature and high-pressure steam enters the steam turbine, it impacts the blades of the steam turbine at a great speed, transfers energy to the blades of the steam turbine, and drives the rotation of the main shaft of the steam turbine. Under the high-speed impact of steam, the steam turbine blades are prone to cavitation damage at the intake side, and in severe cases, the entire blade will be scrapped. Therefore, after a period of operation, the power plant must be shut down for overhaul and replaced with new steam turbine blades. According to the preliminary statistics of the main users of Hangzhou Steam Turbine Co., Ltd., more than 100,000 pieces of scrapped bl...

AI Technical Summary

Problems solved by technology

However, due to the relatively long processing and manufacturing cycle of the current blades, and the design and manufacture of the blades requires constant revisions, it takes a lot of time; high-performance materials are generally expensive, and if traditional billet casting and turning methods are used, the waste of materials is serious. The manufacturing cost of the blade is too high; at the same time, high-performance materials generally have high strength and hardness, and are difficult to turn, and traditional methods are difficult to manufacture; in addition, the blade needs to have a "gradient function" when manufacturing the blade, such as the hardness required at the inlet edge of the blade High, impact resistant, while toughness is required elsewhere to resist sustained torsional stress

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