Ultrasonic flaw detection method of weld joint at U-shaped angle of rib of steel bridge plate unit

Abstract

The invention discloses an ultrasonic flaw detection method of a weld joint at a U-shaped angle of rib of a steel bridge plate unit. The method comprises the steps of: weld joint flaw detection: using a panel of the U-shaped angle of rib as a detection surface, and adopting an RB-2 test block as a reference sensitivity calibration block and adopting an angle probe of 2.5-5MHz and K1.5 to detect; weld penetration detection: respectively arranging grooves which are different in depths along the thickness direction on an 8mm thick steel plate, wherein the probe is 5MHz9*9K2.5 or 2.5MHz 13*13K2.5 during detection; placing the probe on a reference block to find the maximum reflective signal of each groove and record the equivalent dB values; and making a dB-weld penetration curve through relations between the equivalent dB values and dB values in the corresponding depths of the reference block to judge the actual penetration of the weld joint at the U-shaped angle of rib. The method provided by the invention solves the problems that near surface nondestructive detection is just performed on the U-shaped angle of rib of the steel bridge plate unit by using magnetic powder, and the flaws in the weld joint cannot be detected.

Description

technical field [0001] The invention relates to a detection method for U-rib fillet welds of steel bridge slab units, in particular to an ultrasonic flaw detection method for U-rib fillet welds of steel bridge slab units. Background technique [0002] As the main component of the orthotropic plate of steel bridge, U-rib directly bears the local load of the wheel, and the fillet weld of U-rib is very important for the fatigue and durability of steel bridge. At present, magnetic particle testing is mostly used for the detection of U-rib fillet welds of steel bridge plate units at home and abroad, but magnetic particle testing is only suitable for surface and near-surface defect detection, and cannot detect the penetration depth and internal defects of welds. At present, for the detection of U-rib weld penetration, it is generally verified by anatomical test of welding test plate, and the number of welding test plates is small, and second, it is often different from the actual ...

AI Technical Summary

Problems solved by technology

Since the thickness of the U rib plate is only 8mm, it is required that the incomplete penetration of the weld seam is not more than 2mm, and no welding leakage is allowed, and the angle between the U rib plate and the bottom plate is different from the normal fillet weld. The normal fillet weld is 90°, and it An obtuse angle greater than 90° forms an obtuse angle, which brings great difficulties to ultrasonic detection. The reflected wave of the defect is seriously interfered by the root of the weld and the reflected wave on the surface. Overlap occurs, which is not conducive to ultrasonic detection and judgment

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