Ultrasonic testing method for weld area of ​​Stellite alloy sheet of steam turbine blade

Abstract

The invention provides an ultrasonic detection method for the weld area of ​​the Stellite alloy sheet of the steam turbine blade, which can overcome the unfused defect that the gap between the Stellite alloy sheet and the base metal of the steam turbine blade cannot be effectively detected by traditional X-ray radiography , so as to ensure the production quality of the product. According to the ultrasonic pulse reflection method, it scans and detects the unfused defect of the Stellite alloy sheet weld area of ​​the steam turbine blade. The ultrasonic probe of the ultrasonic flaw detector adopts a double-crystal straight probe, and a double-crystal straight probe The frequency is 5Hz, and the moving direction of the double-crystal straight probe is perpendicular to the sound insulation layer in the double-crystal straight probe during scanning and detection. Observe the waveform display screen of the ultrasonic equipment during the scanning process. According to the waveform displayed on the waveform display screen Figure to analyze and determine whether there are unfused defects in the weld zone of the Stellite alloy sheet, if there is an unfused defect, continue to scan the weld zone of the Stellite alloy sheet with the double crystal straight probe to detect the presence of the unfused defect Horizontal length, vertical length.

Description

technical field [0001] The invention relates to the technical field of non-destructive flaw detection, in particular to the field of defect detection of steam turbine blade welds, in particular to an ultrasonic detection method and a probe for the weld area of ​​a Stellite alloy sheet of a steam turbine blade. Background technique [0002] For the last stage or second last stage blade of the steam turbine unit, in order to prevent corrosion, a piece of Stellite alloy sheet is usually welded by brazing method on the water side of the top of the blade. The traditional brazing quality inspection method is to detect the alloy by X-ray radiography For the non-fusion defects of the sheet and the base metal, the surface pores and cracks are checked by surface penetration testing, and the quality can generally be guaranteed. However, for some unfused defects, the resolution of X-ray photography is low because the gap is extremely small and the sheet is perpendicular to the direction...

AI Technical Summary

Problems solved by technology

[0003] In view of the above problems, the present invention provides an ultrasonic detection method for the weld area of ​​the Stellite alloy sheet of the steam turbine blade, which can overcome the inability of traditional X-ray radiography to effectively detect the very small gap between the Stellite alloy sheet of the steam turbine blade and the base material Unfused defects, thus ensuring the quality of product production

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