JPS6241241Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a comparison test piece used for electric resistance welded steel pipes and the like.

In order to manufacture electric resistance welded steel pipes and the like and receive favorable reviews from customers, it is natural for a manufacturer to supply the products through various tests.

As one of these various tests, ultrasonic flaw detection is performed on the welded portion of the electric resistance welded steel pipe to detect abnormalities in the welded portion in advance and remove defective welded portions.
The test pieces used for this test are specified in detail by API standards. That is, it is called a comparative test piece, and is specified by the American Petroleum Institute for adjusting the sensitivity of ultrasonic flaw detection of welded parts of raw pipes mainly used for line pipes and the like.

To be more specific, regarding the materials used for pipe making,
Use test pieces with the same material, outer diameter, and wall thickness.
An artificial flaw of a predetermined shape and a predetermined depth is formed on the test piece, and the artificial flaw is used for adjusting the sensitivity of ultrasonic flaw detection. Due to the conditions imposed on the comparative test piece as described above, the conventional comparative test piece had the following disadvantages. In other words, the conventional comparison test piece uses a steel pipe of a desired length, cuts the steel pipe to create artificial flaws, creates artificial flaws on the outer and inner surfaces of the steel pipe, then welds the cut points, and performs ultrasonic flaw detection. was being carried out. In order to process these artificial defects, steel pipes are cut, welded, etc., which has the disadvantage that the work is complicated and takes a long time. In addition, even if the material is the same, a test piece is required for each case with a different outer diameter and wall thickness, resulting in an enormous number of test pieces, requiring a large space to store and manage the test pieces, and making it impossible to check the accuracy of artificial defects on the inner surface. It had the disadvantage that it was possible.

The present invention advantageously solves the above-mentioned drawbacks, and its gist is that, in the main tube used for comparison tests, a test piece that forms part of the main tube is detachable, and a This is a comparison test piece with artificial flaws for sensitivity adjustment in sonic flaw detection.

In other words, the present invention provides a test piece that can be partially attached to and detached from the main pipe.For example, if the outside diameter is the same but only the wall thickness is different, only the detachable test piece can be replaced and the same main pipe used as before. It was designed to
It also facilitates checking the accuracy of artificial defects on the inner surface and improves the accuracy of artificial defects on the test piece, which is extremely advantageous.

Next, the comparison test piece of the present invention will be explained in detail using FIGS. 1 to 4. Comparison test piece 1 uses a main pipe (steel pipe) 2 having the same material, outer diameter, and wall thickness as the manufactured electric resistance welded steel pipe, and having a length of about 5 m. The reason for making the main pipe 2 as long as 5 m is that it is necessary to carry out the test while moving the main pipe 2. A test piece 3 is provided by making a part of such a main pipe 2 detachable. In order to make the test piece 3 removably attachable to the main pipe 2, protrusions 4 are provided at both longitudinal ends of the test piece 3.
will be established. When viewed from the plane (the first
Figure) This eliminates the lateral vibration between the main pipe 2 and the test specimen 3, and when viewed from the cross section (the second
Figure) A step is created between the main pipe 2 and the test piece 3 to prevent the test piece 3 from falling.

Desired artificial flaws 5 are provided on the outer and inner surfaces of such a removable test piece 3 and ultrasonic flaw detection is performed. With this removable test piece 3, it is easy to process the artificial flaw 5, and the complicated work of cutting the main tube 2, processing the artificial flaw 5, and welding it as in the conventional method is eliminated, which is extremely advantageous. It is something. In addition, if the outer diameter of the main tube 2 is the same but only the wall thickness is different, only the test piece 3 can be replaced, and the test can be performed with one main tube 2. Therefore, the number of main tubes 2 can be reduced, and the comparison test piece can be used. This is extremely advantageous since only a small amount of storage space is required.

Reference numeral 6 in the figure is a space that allows the test piece 3 to be easily grasped when the test piece 3 is attached or removed.

[Brief explanation of the drawing]

Fig. 1 is a plan view of a comparison test piece of the present invention, Fig. 2 is a sectional view taken along line A-A in Fig. 1, and Fig. 3 is a cross-sectional view taken along line B--
B sectional view and FIG. 4 are CC sectional views taken along line C-C in FIG. 1. 1... Comparative test piece, 2... Main pipe, 3... Test piece, 4...
Convex part, 5... Artificial flaw, 6... Space part.

Claims (1)

[Scope of utility model registration request] A comparison test piece comprising a mother pipe used for a comparison test, in which a test piece constituting a part of the mother pipe is detachable, and an artificial flaw for sensitivity adjustment in ultrasonic flaw detection is provided on the test piece.