Method for reconstructing residual stress field of profile of large-dimension fir-type blade wheel groove

Abstract

The invention relates to a method for reconstructing a residual stress field of a profile of a large-dimension fir-type blade wheel groove, comprising the following steps of: selecting a plurality of discrete points on the outline profile of a fir-type milling cutter as detection points to obtain the equivalent cutting speed, the equivalent cutting thickness and the equivalent feed speed of a standard cutting experiment carried out by using a standard integral cylindrical end milling cutter; obtaining the residual stress simulated by a finite element of each detection point by adopting an infinitesimal modeling method; carrying out the standard cutting experiment, measuring the residual stress by adopting an X-ray diffraction method and a corrosion method, and correcting an equivalent two-dimensional orthogonal cutting finite element model; simulating other discrete points by utilizing the corrected simulation model to obtain the residual stress of each discrete point, and thereby fitting to obtain the residual stress field distribution of the integral blade wheel groove profile. The method reduces subsequent rolling treatment times by aiming at the complex profile processing of the wheel groove, and thereby, the production efficiency is greatly improved, and the consumption cost of a rolling tool is reduced.

Description

Technical field [0001] The invention relates to a method in the technical field of mechanical cutting, in particular to a method for reconstructing the residual stress field of the groove profile of a large-size fir tree-shaped blade root wheel. Background technique [0002] The rotor groove is the part that connects the main shaft of the steam turbine rotor and the blades. During the startup and shutdown of the steam turbine, it not only bears the alternating thermal stress generated by the temperature difference in the steam turbine room, but also bears the alternating tensile and compressive stress of the blade on the surface of the groove The working environment of 1000MW supercritical steam turbine rotor wheel groove is high temperature, high pressure and water vapor. The wheel groove has a large load capacity. The residual stress state of the wheel groove is very important to the life of the wheel groove. The root of the last stage wheel groove is required to be 0.5mm from t...

AI Technical Summary

Problems solved by technology

The rolling process can introduce residual stress, but the rolling parameters and rolling times need multiple tests to determine

[0005] After searching the existing literature, no public reports have been found so far on the reconstruction method of the residual stress field of the large-scale fir tree-shaped blade root groove profile of the 1000MW supercritical steam turbine rotor groove

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