Low-melting-point alloy casting positioning technology in turbine blade machining

Abstract

The invention discloses a low-melting-point alloy casting positioning technology in turbine blade machining. The low-melting-point alloy casting positioning technology is achieved through the following steps: (1) conducting rough machining on a blade; (2) matching the blade with a positioning tool, wherein the blade is transversely arranged after the rough machining on the blade is completed, a blade crown at the head of the blade is abutted against a single tip of the positioning tool, a blade root at the tail of the blade is abutted against double tips of the positioning tool, and a blade steam passage in the middle of the blade penetrates through a positioning square box; (3) casting tin-bismuth alloy molten liquid molten at a certain temperature in the positioning square box, and casting and cooling the positioning square box at the same time until tin-bismuth alloy is solidified and fixed; (4) conducting fine machining on the blade crown and the blade root; (5) melting the tin-bismuth alloy again, pouring out the tin-bismuth alloy molten liquid from the positioning square box, and removing the positioning square box; (6) conducting fine machining on the blade steam passage. The low-melting-point alloy casting positioning technology in the turbine blade machining can meet the requirements for machining blades of various shapes and sizes, the positioning effect is good, and raw materials are greatly saved.

Description

technical field [0001] The invention relates to a low-melting-point alloy casting and positioning process in the processing of steam turbine blades, and belongs to the technical field of finishing of steam turbine impellers. Background technique [0002] The steam turbine blade is an important part of the steam turbine. The processing technology and precision of the blade affect the working efficiency of the steam turbine to a large extent. The strength of the blade also plays an important role in the safety and maintenance of the steam turbine. The design of twisted blades with variable cross-section has become more and more common. At the same time, as the power of the unit increases, the blades are made longer and longer. The increase of the height of the blade will cause the problem of insufficient rigidity when the blade is processed. The blade processing technology must solve the above problems. [0003] The steam turbine blade is sequentially composed of three parts...

AI Technical Summary

Problems solved by technology

[0004] For some blade roots with toothed or other curved surfaces, it is impossible to process them by adding a process head on the end surface of the blade root

When the blade root is processed and formed, if the machined air passage (airfoil) is used as the processing basis, a considerable amount of processing material needs to be added to the air passage, and more machining allowance needs to be removed in the subsequent air passage processing. This will result in an increase in the product material and processing time, and the deformation of the processing will become larger

[0005] In the prior art, such as Chinese patents CN101767233B and CN102091919B, both methods waste a lot of raw materials. At the same time, when processing the middle part of the blade, constant correction is required, and the positioning method is unstable.

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