ISO 10893-10:2011 pdf download – Non-destructive testing of steel tubes —Part 10: Automated full peripheral ultrasonictesting of seamless and welded (exceptsubmerged arc-welded) steel tubes for the detection of longitudinal and/ortransverse imperfections.
4 General requirements
4.1 Unless otherwise specified by the product standard or agreed on by the purchaser and manufacturer, this ultrasonic testing shal be carried out on tubes after completion of all the pnmary production process operations (rolling, heat treating, cold and hot working, sizing and straightening, etc.).
4.2 The tubes under test shall be sufficiently straight to ensure the validity of the test. The surfaces shall be sufficentty tree of foreign matter which can Interfere with the validity of the test.
4.3 This test shall be carried out by suitable trained operators qualified in accordance with ISO 9712. ISO 11484 or equivalent and supervised by competent personnel nominated by the manufacturer. In the case of inspection, this shall be agreed on by the purchaser and manufacturer.
The operating authorization issued by the employer shall be according to a wfltten procedure. Non-destructive testing (NDT) operations shal be authorized by a level 3 NDT individual approved by the employer.
NOTE The definition of levels 1. 2 and 3 can be found in appropriate International Standds. e.g. ISO 9712 and ISO 11484.
5 Test method
5.1 The tubes shall be tested by usrng an ultrasonic shear wave technique for the detection of longitudinal and transverse lmpedectlons. Lamb wave technique may be applied tot the detection of longitudinal imperfections.
5.2 During testing, the tubes and the transducer assembly shall be moved relative to each other such that the whole of the tube surface is scanned, with coverage calculated on the dimension of the transducer(s). The relative speed of movement during testing shall not vary by more than ±10 %. There can be a short length at both tube ends which cannot be tested. Any untested ends shall be dealt with in accordance with the requirements of the appropriate product standard (see Annex B).
5.3 Unless otherwise agreed on by the purchaser and manufacturer. testrng shall be carried out in two opposite directions of Sound propagation for the requested type of inspection, clockwise arid anbclockwise for the detection of longitudinal defects and forward and backward for the detection of transversal defects.
5.4 For the detection of longitudinal imperfections, the maximum width of each individual transducer, measured parallel to the major axis of the tube, shall be 25 mm. For Ui category tubes with an outside diameter equal to or less than 50 mm. the width of any one transducer unit shall normaly be restricted to a maximum of 12,5 mm.
In the case of use of the Lamb wave technique or phased array technique, the maximum width of transducer or active aperture, measured parallel to the major axis of the tube, shall be limited to 35 mm.
For the detection of transversal Imperfections, the maximum width of each individual transducer, measured perpendicular to the major axis of the tube, shall be 25 mm
5.5 The ultrasonic test frequency of transducers that shall be used shall be in the range 1 MHz to 15 MHz for shear wave technique and in the range 0.3 MHz to 1 MHz for Lamb wave technique, depending on the product condition and properties, the thickness and surface finishing of tubes under examination.
5.6 The equipment shall be capable of classifying tubes as either acceptable or suspect, by means of an automated triggerlalarm level combined with a marking and/or sorting system.
6.1.3 The reference tubes shall have the same nominal diameter and thickness, same surface finish anddelivery condition (e.g. as-rolled, normalized, quenched and tempered) as the tubes under test, and shall havesimilar acoustic properties (e.g. sound velocity and attenuation coefficient).
6.1.4In order to obtain clearly distinguishable signals, the notches shall be sufficiently separated from theends of the reference tubes and from each other.
6.2Types of reference notches
6.2.1 The reference notches shall lie parallel (longitudinal notches) or transverse(transverse notches) tothe major axis of the reference tube.
The reference notches shall be of the “N” type(N-notch); the “V” type notch (V-notch) may be used at thediscretion of the manufacturer when the specified notch depth is less than 0,5 mm (see Figure 1). In the caseof “N” type notch, the sides shall be nominally parallel and the bottom shall be nominally square to the sides.NOTE The botiom or the bottom corners of the notch can be rounded.