High and medium-temperature heat treatment deformation preventing device for large turbine blades

Abstract

The invention relates to a deformation preventing device, in particular to a high and medium-temperature heat treatment deformation preventing device for large turbine blades. The device is characterized by being formed by assembling a casting support frame and supporting cushion blocks for supporting the casting support frame; the casting support frame is formed by assembling a U-shaped groove in the middle, groove walls on two sides of the U-shaped groove and a triangular side support which is fixed at each of two ends of the outer side of each groove wall; three cross beams with arc-shapedtops and different heights are fixed in the U-shaped groove at intervals; and two groove columns are fixed at each edge of the U-shaped groove. The device can make up the defects of the conventional blade heat treatment technology and prevent deformation of the blades in the heat treatment process according to the conventional heat treatment process mode, the characteristics of a trolley furnace and the overall dimension of the blades of different types.

Description

technical field [0001] The invention relates to an anti-deformation device, in particular to an anti-deformation device for high and medium-temperature heat treatment of blades of large water turbines. Background technique [0002] The material of the blade of the large water turbine is ZG0Cr13Ni4Mo, which belongs to high-alloy steel. Its outline size is 5245×4705×2406mm. The thickness of the blade is very different, the thickest part is 379mm, and the thinnest part is 30mm, which is a curved surface casting with variable space section. The NTT heat treatment process is adopted for this kind of blade to meet the mechanical performance requirements of the material, namely: primary normalizing plus secondary tempering: normalizing temperature 1020~1050℃, primary temperature 610~650℃, secondary temperature 570~580℃. The blades are prone to warping and deformation during such high and medium temperature heat treatment. [0003] In the stage of R & D and production of blades, t...

AI Technical Summary

Problems solved by technology

The entire furnace installation process takes about 16 hours, and these supporting pads block the gas channel of the trolley furnace, and the castings are placed directly on the gas furnace surface, which also violates the use requirements of the furnace and affects the uniformity of the furnace temperature. The pad iron has a large amount of heat storage, and when it is cooled by normalizing, it will make the lower part of the blade thick and mostly difficult to cool, and it will also produce a large temperature difference and thermal stress, which will cause a large deformation of the blade. The deformation is 2~10mm. At present, there is no way to prevent this. deforming device

Images