A Thin Plate Ultrasonic Testing Method with B-scan Function

Abstract

The invention discloses an ultrasonic sheet detection method with a B-scanning function .The method comprises the steps that an ultrasonic probe is connected with an ultrasonic flaw detector and aligned with a sheet to be tested separately; whether an A-scanning mode or a B-scanning mode is selected is judged; in the A-scanning mode, the positions of the ultrasonic probe and the sheet to be tested are adjusted, and flaw detecting is conducted; whether a flaw is generated on a wave gate or not is judged, and if yes, flaw detecting is continuously conducted; a peak value is kept, fixed and then displayed; when the B-scanning mode is selected, the ultrasonic flaw detector is started and enters a B-scanning mode interface; the positions of the ultrasonic probe and the sheet to be tested are adjusted, and then the ultrasonic probe is moved; the ultrasonic flaw detector collects the thicknesses of all points of the sheet to be tested in real time, and a B-scanning graph is formed by combining the thicknesses with the scanning and detecting time and then displayed .According to the method, the detection cost is low, other equipment such as an encoder does not need to be additionally arranged, the detection efficiency is high, operation can be completed through one person, the detection result is displayed on a screen in a graph mode and is visual, the variation trend of a workpiece is clear at a glance, detection personnel can conveniently judge the quality of the workpiece, and detained detection can be conducted on the suspicious portion in a targeted mode.

Description

technical field [0001] The invention relates to a thin plate ultrasonic testing device. In particular, it relates to a thin plate ultrasonic testing method with B-scan function used in chemical, petrochemical, pharmaceutical, metallurgical and other industrial fields. Background technique [0002] Sheet metal is an important raw material for industrial production. In today's steel structure engineering, sheets with a thickness of 4 to 8 mm are widely used. The production process of the metal sheet determines that the most likely defect type is the layered defect parallel to the surface of the material, which seriously affects the quality of the finished product. [0003] At present, various industrial departments at home and abroad use the ultrasonic Lamb wave method or the ultrasonic shear wave pulse reflection method for the non-destructive testing of the internal quality of the metal sheet. The ultrasonic Lamb wave method has a fast detection speed, but there are seriou...

AI Technical Summary

Problems solved by technology

Ultrasonic flaw detection in the near-field area is not good for quantification. The echo of larger defects at the minimum value of sound pressure may be lower, while the echo of smaller defects at the maximum value of sound pressure may be higher, which affects the Defect judgment; because the thickness of the base metal of the thin plate is relatively thin, it is basically in the near-field area of ​​the ultrasonic field, which is easy to cause misjudgment or missed inspection

Therefore, it is not suitable to use the method of longitudinal wave single crystal probe to detect the quality of thin plate base metal and thin plate weld seam.

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