GB/T 41115-2021
Non-destructive testing of welds—Ultrasonic testing—Use of time-of-flight diffraction technique (TOFD) (English Version)

Standard No.

GB/T 41115-2021

Language

Chinese, Available in English version

Release Date

2021

Published By

国家市场监督管理总局、中国国家标准化管理委员会

Latest

GB/T 41115-2021

Scope

This document specifies the application of semi-automatic or fully automatic ultrasonic time-of-flight diffraction (TOFD) technology for fusion welding joints of metal materials with a thickness not less than 6 mm. This document applies to full-penetration welded joints of simple geometry for plates, pipes and vessels, where both the weld metal and the base metal are low-carbon or low-alloy steels. Under appropriate circumstances, TOFD can also be used on other materials with lower ultrasonic attenuation (especially scattering attenuation). This document provides relevant regulations for TOFD application under the condition that the sound velocity of longitudinal wave is (5920±50)m/s and the sound velocity of shear wave is (3255±30)m/s. When testing other materials with different sound velocities, it is necessary to consider the influence of sound velocity. This document refers to ISO 16828 and provides guidance on the application of TOFD technology to the detection, location and dimensional measurement of discontinuities in fusion welded joints, as well as the specific functions and limitations of this technology. In manufacturing process testing and in-service testing, TOFD can be used as a single technique or in combination with other nondestructive testing (NDT) methods or techniques. This document establishes four test levels (A, B, C and D) in accordance with the provisions of ISO17635. The higher the detection level, the higher the detection reliability. This document also provides guidance on selecting the level of detection. This document allows evaluation of TOFD indications for subsequent acceptance. The evaluation is based on the evaluation of the transmitted wave, reflected wave and diffracted wave signals of TOFD images. This document does not cover discrete acceptance levels.

GB/T 41115-2021 Referenced Document

• ISO 16828 Non-destructive testing - Ultrasonic testing - Time-of-flight diffraction technique as a method for detection and sizing of discontinuities
• ISO 17640 Non-destructive testing of welds - Ultrasonic testing - Techniques, testing levels, and assessment
• ISO 5577 Non-destructive testing - Ultrasonic testing - Vocabulary
• ISO 9712 Non-destructive testing — Qualification and certification of NDT personnel

GB/T 41115-2021 history

• 2021 GB/T 41115-2021 Non-destructive testing of welds—Ultrasonic testing—Use of time-of-flight diffraction technique (TOFD)