Method for detecting T-shaped groove in rotor rim of steam turbine

Abstract

The invention relates to a method for detecting a T-shaped groove in a rotor rim of a steam turbine. The method disclosed by the invention comprises the following steps: performing cover scanning on a to-be-detected position by adopting an ultrasonic phased array inspection device, performing time synchronization on interface waves and impulse transmission waves of the T-shaped groove, and compiling imaging software so as to realize ultrasonic phased array real-time imaging detection, so that the detection of the T-shaped groove in the rim is reliable and convenient, and misjudgment and missing detection can be avoided. Compared with the conventional ultrasonic detection method, the method disclosed by the invention has the advantages that the T-shaped groove of the impeller is subjected to flaw detection by adopting the ultrasonic phased array real-time imaging detection technology, full-coverage scanning of a reverse T-shaped groove can be completed under the conditions that the scanning range is wide, the defect waves are easily identified and a probe does not need to move back and forth, the detection efficiency is improved, and location and quantification of crack defects can be realized.

Description

technical field [0001] The invention relates to a method for detecting a T-shaped groove of a wheel flange of a steam turbine rotor. Background technique [0002] As the core component of a thermal power plant, the steam turbine rotor has long been affected by factors such as high temperature, high pressure, centrifugal force, exciting force, corrosion, vibration, and water droplet erosion in the wet steam area. The working conditions are extremely harsh, especially in the T-shaped groove of the rotor impeller Stress corrosion cracks and fatigue cracks are easily formed at the sharp corners of the blades. As the cracks expand, the crack area becomes larger and the remaining bearing area becomes smaller and smaller. When the remaining bearing area is not enough to withstand the centrifugal force of the blade, the remaining area will be It breaks instantaneously in a shearing manner, causing the rim and the blades in the T-shaped groove of the rim to fall off. Once the blade ...

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Problems solved by technology

[0003] For the non-destructive testing of the T-groove of the steam turbine rotor flange, the current method is to use multiple probes with different angles to scan repeatedly, or to cover and scan the workpiece by moving a certain probe back and forth, which is very troublesome to scan. For example, the Chinese patent application publication number CN106053598A adopts this scanning method, and the signal emission point of the ultrasonic probe moves in a moving area to realize coverage scanning. The scanning process is very cumbersome, and the structure of the scanning needs to be Only by comparing with the standard sample can the fixed wave, interference wave and defect wave be distinguished, which requires high practical experience and operational skills of the inspectors, and the detection efficiency is very low

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