JPH06167479A - Butt welding joint to be nondestructively inspected - Google Patents

Abstract

PURPOSE:To effectively detect a defect based on a penetration malfunction by increasing an ultrasonic reflection echo in the case of the penetration malfunction in a butt welding joint to be detected for a welding defect (penetration malfunction) to be conducted by a nondestructive inspection by an ultrasonic fault detection. CONSTITUTION:In the case of welding materials 3, 4A to be welded and butt disposed from one side of a butt position, a chamfered part 4b is formed at an edge 4a of one material 4A to be welded opposed to the other material 3 to be welded at an opposite side to a welding side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a butt-welded joint for detecting welding defects (defective penetration) by nondestructive inspection by ultrasonic flaw detection.

[0002]

2. Description of the Related Art Conventionally, as a technique for detecting and confirming a welding defect of a welded joint by a nondestructive inspection using an ultrasonic flaw detector, for example, one disclosed in JP-A-2-212762. There is.

Specifically, a case where a welding defect (defective penetration) is detected by nondestructive inspection using an ultrasonic probe 2 after welding a butt-welded joint 1 as shown in FIG. explain. Butt welded joint 1 shown in FIG.
Is a plate-like welded material 3 arranged along the vertical direction,
It is composed of a plate-shaped welded material 4 arranged along a direction (horizontal direction) orthogonal to this welded material 3, and these welded materials 3 and 4 are butted with their upper surfaces flush with each other. It is arranged and formed.

Then, welding is performed by laser welding or the like from above the butt position of the butt-welded joint 1, and the welded material 3,
After welding is performed by forming the welded portion 5 extending between the four, the ultrasonic probe 2 is placed on the upper surface of the material 4 to be welded, and ultrasonic flaw detection is performed by the ultrasonic probe 2. That is, ultrasonic waves are oscillated from the ultrasonic probe 2 toward the abutting position (welding portion 5) between the materials 3 and 4 to be welded, and the reflected echo of the ultrasonic waves is measured by the ultrasonic probe 2.

Usually, when the welded portion 5 is reliably formed between the materials 3 and 4 to be welded and no defective penetration occurs, ultrasonic waves pass through the welded portion 5 and the reflected echo is small. However, as shown in FIG. 3, if the welded portion 5 is not sufficiently formed and the penetration is shallow, and a defective penetration portion (defective portion) 6 occurs, most of the ultrasonic waves are reflected at that portion. And the reflected echo becomes large. Therefore, it is possible to detect the reflected echo by the ultrasonic probe 2 and determine the presence or absence of a defect (defective penetration) based on the size of the reflected echo.

[0006]

However, in the conventional butt-welded joint 1 described above, even if the poor penetration portion 6 as shown in FIG. In some cases, ultrasonic waves may pass through the poor-melting portion 6. In such a case, the reflected echo detected by the ultrasonic probe 2 becomes small, and there is a problem that the defect cannot be detected despite the defect.

The present invention is intended to solve such a problem. In the case of defective penetration, the reflected echo of ultrasonic waves is increased so that defects caused by defective penetration can be eliminated in nondestructive inspection by ultrasonic flaw detection. An object of the present invention is to provide a non-destructive inspection butt welded joint that can be reliably detected.

[0008]

In order to achieve the above object, a non-destructive inspection butt-welding joint of the present invention is one in which materials to be welded arranged in butt are welded from one side of the butt position. At least one of the materials to be welded is characterized in that an edge portion facing the other material to be welded on the side opposite to the welding execution side is chamfered.

[0009]

In the above-described butt-welding joint for non-destructive inspection of the present invention, by chamfering the edge portion, even if the materials to be welded are butt-disposed with a high degree of adhesion, the chamfered portion adheres closely. Therefore, when the penetration due to welding is shallow and a penetration failure occurs, the ultrasonic waves are reliably reflected at the chamfered portion and the reflection echo becomes large.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A non-destructive inspection-compatible butt-welding joint as an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic side view thereof, and FIG. FIG. 2 is a side view schematically showing the absence state.
(b) is a side view which shows typically the penetration failure state in the butt welding joint.

As shown in FIG. 1, the butt-welded joint 1A of the present embodiment is similar to the conventional butt-welded joint shown in FIG. 3, and has a plate-shaped welded material 3 arranged along the vertical direction, It is composed of a plate-shaped welded material 4A arranged along a direction (horizontal direction) orthogonal to the welded material 3, and these welded materials 3 and 4A are butted with their upper surfaces flush with each other. It is arranged and formed. In this embodiment as well, welding is performed by laser welding or the like from above the butt position of the butt-welded joint 1A.

In the present embodiment, the plate-shaped material to be welded 4A arranged along the horizontal direction is provided at the edge portion 4a facing the material to be welded 3 on the side opposite to the welding execution side, that is, on the lower side. A chamfered portion 4b is formed. The dimension x of the chamfered portion 4b shown in FIG. 1 is set within a range of 0.1 mm ≦ x ≦ 0.5 mm when the plate thickness of the welded material 4A is 6 mm, for example. The chamfered portion 4b does not need to be formed with a very high precision, and a sufficient effect can be obtained only by sanding.

Butt welded joint 1 constructed as described above
A case where a welding defect (defective penetration) is detected by nondestructive inspection using the ultrasonic probe 2 after performing laser welding on A will be described.

The laser welding method is, for example, a coaxial shield method (N ₂
A gas of 30 l / min and a welding speed of 1 m / min) is used. Further, for example, as the ultrasonic flaw detector, an echograph 1030 manufactured by Nippon Mattik Co., Ltd. is used, and as the ultrasonic probe 2, 10 kHz, 5 mm × 5 mm square, 70 ° oblique angle probe (manufactured by Nippon Mattik Co., Ltd. UM-10C5 × 5A70) is used, and as the contact medium, an echo call manufactured by Nippon Matic Co., Ltd. is used. Then, as a reflection echo height reference when determining a defect, it is determined as a non-defective product (sufficient melting and no defect) when the reflection echo height is -16 dB or less.

Now, as shown in FIGS. 2 (a) and 2 (b), the welded portion 5 extending between the welded materials 3 and 4A is formed by laser welding, and after welding, the welded material 4 is formed. The ultrasonic probe 2 is placed on the upper surface of the, and ultrasonic flaw detection by the ultrasonic probe 2 is performed. That is, ultrasonic waves are oscillated from the ultrasonic probe 2 toward the abutting position (welding portion 5) of the materials 3 and 4A to be welded, and the reflected echo of the ultrasonic waves is measured by the ultrasonic probe 2.

As shown in FIG. 2 (a), when the welded portion 5 is reliably formed between the materials to be welded 3 and 4A and there is no penetration failure, ultrasonic waves pass through the welded portion 5. Therefore, the reflected echo becomes smaller, and the defect (defective melting)
It can be judged that there is no.

Although no filler metal is added in laser welding, the welding heat-affected parts of the materials to be welded 3 and 4A contract in the directions in which the materials to be welded 3 and 4A are attracted to each other. Even if the chamfered portion 4a is formed on one of the welded materials 4A of the welded joint 1A, if sufficient penetration can be obtained by laser welding, a gap due to the chamfered portion 4a is obtained as shown in FIG. 2 (a). Will be filled up by the weld 5.

On the other hand, as shown in FIG. 2 (b), when the welded portion 5 is not sufficiently formed and the weld penetration is shallow, resulting in poor weld penetration, in this embodiment, the edge portion 4 of the workpiece 4A is welded.
Since the chamfered portion 4b is formed on a, the material to be welded 3,
Even if the 4A's are butt-disposed with a high degree of adhesion, the gap by the chamfered portion 4b remains formed, the ultrasonic wave is reliably reflected by the chamfered portion 4b, and the reflected echo becomes large. Therefore, in the case of defective penetration, the reflected echo of ultrasonic waves becomes large, and defects due to defective penetration can be reliably detected during nondestructive inspection by ultrasonic flaw detection.

The present invention is not limited to the above-mentioned embodiments, and is included in the scope of the present invention even if the design is changed without departing from the gist of the present invention. For example, in the above-described embodiment, as shown in FIG. 1, a case has been described in which the materials to be welded 3 and 4A arranged along mutually orthogonal directions are butt-welded, but the present invention is not limited to this. However, the present invention is also applicable to various other butt-welded joints, such as a butt-welded joint in which plate-shaped materials to be welded are horizontally butted and arranged.

[0020]

As described in detail above, according to the butt-welding joint for nondestructive inspection of the present invention, at least one of the materials to be welded is welded to the other side on the side opposite to the welding side. By chamfering the edge part facing the material to be welded, the reflected echo of ultrasonic waves becomes large in the case of defective penetration, so that defects due to defective penetration can be reliably detected during nondestructive inspection by ultrasonic flaw detection. effective.

[Brief description of drawings]

FIG. 1 is a side view schematically showing a non-destructive inspection butt-welding joint as an embodiment of the present invention.

FIG. 2A is a side view schematically showing a defect-free state of the butt-welding joint of the present embodiment, and FIG. 2B is a side-view schematically showing a poor penetration state of the butt-welding joint of the present embodiment. Is.

FIG. 3 is a schematic side view for explaining a nondestructive inspection using a conventional butt-welded joint and an ultrasonic probe.

[Explanation of symbols]

 1A Butt welded joint 2 Ultrasonic probe 3,4A Welded material 4a Edge part 4b Chamfered part 5 Welded part

Claims (1)

[Claims] 1. A butt-welding joint for welding materials to be welded in a butt arrangement from one side of the butt position, wherein at least one of the materials to be welded is a welding execution side. A non-destructive inspection butt-welding joint characterized in that an edge portion facing the other material to be welded on the opposite side is chamfered.