CN102721742A - Ultrasonic flaw detection method of weld joint at U-shaped angle of rib of steel bridge plate unit - Google Patents

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

The ultrasonic detection method of a kind of steel bridge beam slab unit U angle of rib weld seam

Technical field

The present invention relates to the detection method of steel bridge beam slab unit U angle of rib weld seam, relate in particular to the ultrasonic detection method of a kind of steel bridge beam slab unit U angle of rib weld seam.

Background technology

The U rib directly bears the local action of wheel load as the critical piece of steel bridge beam orthotropic plate, and U angle of rib weld seam is most important for steel bridge beam fatigue and permanance.And the detection of steel bridge beam slab unit U angle of rib weld seam at present both at home and abroad adopts magnetic to detect more, but magnetic detects the defects detection that only is applicable to surface and nearly surface, can't detect for the fusion penetration and the inherent vice of weld seam.For the detection of U rib weld penetration, generally be to adopt test piece for welding to dissect test in advance with checking, and test piece for welding one is a negligible amounts, the 2nd at present, often the actual welds with the U rib has certain difference, can not represent actual welds fully.Because the thick 8mm that is merely of U floor requires the lack of penetration 2mm of being not more than of weld seam, can not weld leakage again; And the angle of U rib and base plate is different with usual fillet weld, and normal fillet weld is 90 °, and it forms obtuse angles greater than 90 °; This has brought great difficulty for hyperacoustic detection, and flaw echo receives the root of weld and surface reflection wave interference very serious, simultaneously; Root of weld signal easily overlaps phenomenon with the reflected signal that defective near root produces, thereby, be unfavorable for the ultrasound examination judgement.

Summary of the invention

Goal of the invention: the objective of the invention is to the deficiency to prior art, provide the ultrasonic detection method of a kind of steel bridge beam slab unit U angle of rib weld seam to make accurate mensuration and also can the butt welded seam inherent vice accurately detect to girder steel plate unit U angle of rib weld penetration.

In order to realize the foregoing invention purpose, the technical scheme that the present invention adopted is:

The ultrasonic detection method of a kind of steel bridge beam slab unit U angle of rib weld seam, the U floor is thick to be 8mm, comprises the steps:

Weld defect detects:

As detection faces, adopt the RB-2 test block with U floor face, adopt 2.5 ~ 5MHz, K1.5 angle probe to detect as the reference sensitivity calibration block;

Apart from width of cloth curve and sensitivity be: declare scrap wire Φ 3 * 40-4dB, quantitatively line Φ 3 * 40-10dB evaluates line Φ 3 * 40-16dB;

Weld penetration detects:

The making of reference block is got the 8mm steel plate and is made reference block, along thickness direction the groove that the degree of depth is 2mm, 3mm, 4mm, 5mm is set respectively;

Probe adopts 5MHz 9 * 9K2.5 or 2.5MHz 13 * 13K2.5 during detection;

Probe is placed in the reference block, and to find out groove depth respectively be the maximum reflection signal of 2mm, 3mm, 4mm, 5mm and write down its equivalent dB value;

Guarantee to examine fully surface state and the reference block basically identical on the workpiece, through with reference block on the dB value of respective depth concern, making dB-fusion penetration curve, thus judge the actual fusion penetration of its U angle of rib weld seam.

The present invention compared with prior art, its beneficial effect is:

(1) the invention solves steel bridge beam slab unit U angle of rib weld seam and can only adopt magnetic to carry out nearly surperficial Non-Destructive Testing, can't detect the problem of weld seam inherent vice;

(2) method of detection of the present invention; Can detect steel bridge beam slab unit U angle of rib effective weld fusion penetration more exactly; So that grasp actual fusion penetration situation, can be optimized and improve welding technology in case of necessity, thereby; Guarantee the workmanship of steel bridge beam slab unit, and improve the fatigue strength and the permanance of steel bridge beam;

(3) through U rib weld seam is carried out ultrasonic inspection, help to improve welder's working sense of responsibility.

Description of drawings

Fig. 1 is this U angle of rib welding line structure synoptic diagram;

The reference block synoptic diagram that Fig. 2 position makes.

Embodiment

Below in conjunction with accompanying drawing, through a most preferred embodiment, technical scheme of the present invention is elaborated, but protection scope of the present invention is not limited to said embodiment.

As shown in Figure 1, U angle of rib weld seam connects U floor face 1 and base plate 2, and the U floor is thick to be 8mm, and the angle of U floor face 1 and base plate 2 is greater than 90 °.

The ultrasonic detection method of a kind of steel bridge beam slab unit U angle of rib weld seam comprises the steps:

Weld defect detects:

As detection faces, adopt the RB-2 test block with U floor face 1, adopt 2.5 ~ 5MHz, K1.5 angle probe to detect as the reference sensitivity calibration block;

Apart from width of cloth curve and sensitivity be: declare scrap wire Φ 3 * 40-4dB, quantitatively line Φ 3 * 40-10dB evaluates line Φ 3 * 40-16dB;

Weld penetration detects:

The making of reference block, the 8mm steel plate of getting as shown in Figure 2 is made reference block, and along thickness direction the degree of depth being set respectively is 2mm groove 3,3mm groove 4,4mm groove 5,5mm groove 6, and groove width is 0.5mm;

Probe adopts 5MHz 9 * 9K2.5 or 2.5MHz 13 * 13K2.5 during detection;

Probe is placed in the reference block, and to find out groove depth respectively be the maximum reflection signal of 2mm, 3mm, 4mm, 5mm and write down its equivalent dB value;

Guarantee to examine fully surface state and the reference block basically identical on the workpiece, through with reference block on the dB value of respective depth concern, making dB-fusion penetration curve, thus judge the actual fusion penetration of its U angle of rib weld seam.

Contrast test: make the defects simulation test specimen, the artificial manufacturing and pre-buried weld defects like crackle, incomplete fusion, slag inclusion, pore etc., verified the feasibility of the inventive method; Make the fusion penetration imitation specimen, and the detected value and the contrast of macroscopical metallographic of ultrasonographic weld penetration are verified.Through contrast test, method of the present invention is rationally feasible.

Claims (1)

1. the ultrasonic detection method of a steel bridge beam slab unit U angle of rib weld seam, the U floor is thick to be 8mm, it is characterized in that, comprises the steps:

Weld defect detects:

As detection faces, adopt the RB-2 test block with U floor face (1), adopt 2.5 ~ 5MHz, K1.5 angle probe to detect as the reference sensitivity calibration block;

Apart from width of cloth curve and sensitivity be: declare scrap wire Φ 3 * 40-4dB, quantitatively line Φ 3 * 40-10dB evaluates line Φ 3 * 40-16dB;

Weld penetration detects:

The making of reference block is got the 8mm steel plate and is made reference block, along thickness direction the groove that the degree of depth is 2mm, 3mm, 4mm, 5mm is set respectively;

Probe adopts 5MHz 9 * 9K2.5 or 2.5MHz 13 * 13K2.5 during detection;

Probe is placed in the reference block, and to find out groove depth respectively be the maximum reflection signal of 2mm, 3mm, 4mm, 5mm and write down its equivalent dB value;

Guarantee to examine fully surface state and the reference block basically identical on the workpiece, through with reference block on the dB value of respective depth concern, making dB-fusion penetration curve, thus judge the actual fusion penetration of its U angle of rib weld seam.

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