Creeping wave detection method for crack defects of austenitic stainless steel pipe for power station boiler

Abstract

The invention discloses a creeping wave detection method for crack defects of an austenitic stainless steel pipe for a power station boiler. The method comprises the following steps: (1) selecting frequencies of a creeping wave probe, a wedge block and a probe, polishing the bottom of the wedge block into an arc surface which is matched with a to-be-detected position of the austenitic stainless steel pipe for the power station boiler; (2) emitting a creeping wave by the creeping wave probe, bonding the creeping wave probe on the wedge block, and adjusting the incident angle of a transmitted longitudinal wave in a wafer wedge block of the creeping wave probe to be 25-27.6 degrees; and (3) attaching the arc surface of the bottom of the wedge block of the creeping wave probe to the to-be-detected position of the austenitic stainless steel pipe for the power station boiler, emitting the creeping wave through the creeping wave probe, emitting the creeping wave to the inner surface and the outer surface of the austenitic stainless steel pipe for the power station boiler, and then judging whether the crack defects exist or not according to the collected reflected waves on the inner surface and the outer surface of the austenitic stainless steel pipe for the power station boiler. According to the creeping wave detection method, detection of the crack defects on the austenitic stainless steel pipe for the power station boiler can be effectively finished.

Description

technical field [0001] The invention relates to a creeping wave detection method, in particular to a creeping wave detection method for crack defects in austenitic stainless steel pipes used in power plant boilers. Background technique [0002] Among the high-temperature pressure-bearing components of coal-fired power plants, the heating surface tubes in the boiler have the worst service conditions, and the operating environments of superheaters and reheaters are particularly harsh. Under the comprehensive effects of high temperature, high pressure, steam oxidation and flue gas corrosion, the material for the heating surface tube in the furnace requires not only high creep strength, but also excellent steam oxidation resistance and flue gas corrosion resistance. Cold workability and weldability. Austenitic heat-resistant steel has excellent comprehensive performance. Austenitic stainless steel has been used in large quantities in the superheater / reheater tubes of supercriti...

AI Technical Summary

Problems solved by technology

Although ultrasonic 5P6mm×6mmK2.5~2.7 shear-wave oblique probes can be used at present to detect the base metal of austenitic stainless steel pipes for boilers, there is a problem that the initial wave width of the shear-wave oblique probes is relatively large during the detection process, which will lead to Missed judgment of near-surface defects, and at the same time, the shear wave oblique probe also emits surface waves, which makes the judgment of defects more difficult

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