A manufacturing process of fir-tree-shaped blade-root type steam turbine blade

Abstract

The invention discloses a manufacturing process of a fir blade root type steam turbine blade. The manufacturing process comprises the steps that A, a process head of a blank of the blade is machined; B, the process head is located through three center holes of the blank of the blade, the process head is clamped through a fixture during machining, rough machining and finish machining are conducted on all parts, except the blade root, of the blade, a blade crown is machined at the blade crown end during finish machining according to the process datum, and the blade crown and a blade root middle body form a large spatial locating surface; C, a fixture for blade root milling is adopted, the machined spatial locating surface is used for locating, and rough machining and finish machining are conducted on the blade root of the blade; D, a blade steam passage is polished. By the adoption of the machining method, the traditional square box pouring technique is eliminated, the machining risk is lowered, and cost is reduced. Meanwhile, a large surface is no longer machined through locating of a small surface, and the small surface is machined through locating of the large surface instead; as a result, the manufacturing accuracy of the large steam turbine blade is greatly improved, and the positional accuracy between the large surface and the small surface is ensured.

Description

technical field [0001] The invention belongs to the field of steam turbine blade manufacturing technology and devices thereof, in particular to a manufacturing method for replacing traditional fir-tree-shaped blade-root die-forging blades with poured alloys. Background technique [0002] As the core component of a steam turbine, whether the manufacturing of the blade is qualified directly affects the efficiency of the steam turbine, especially with the development of material science, the design structure of the final stage blade of the steam turbine is becoming more and more complex, and the size is getting larger and larger, resulting in more and more difficult processing. bigger. [0003] The structure of the steam turbine blade can be divided into three parts: the blade root, the steam channel, and the blade crown. At present, the design trend of the blade of the low pressure cylinder is a fir tree type blade root structure. This type of structure has very high requirem...

AI Technical Summary

Problems solved by technology

[0005] In order to overcome the disadvantages of high manufacturing cost and low qualified rate of large blades caused by the existing manufacturing technology, the present invention provides a new manufacturing technology, using a specially designed fixture to process the large-sized parts first, and finally process the small-sized blades. The root part can effectively reduce the impact of positioning errors on blade processing and ensure the qualified rate of blades

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