GB/T 18852-2002
Ultrasonic non-destructive testing--Reference blocks and test procedures for the characterization of contact search unit beam profiles (English Version)

Standard No.

GB/T 18852-2002

Language

Chinese, Available in English version

Release Date

2002

Published By

General Administration of Quality Supervision, Inspection and Quarantine of the People‘s Republic of China

Status

Be replaced 2021-06

Replace By

GB/T 18852-2020

Latest

GB/T 18852-2020

Scope

This standard recommends two kinds of metal reference test blocks, semicircular step test block (HS test block) and horizontal hole test block (SDH test block). This standard provides methods for the determination of the sound field generated in solids by probes used in contact testing. The measured probes include straight probes, oblique probes (refracted longitudinal waves and refracted shear waves), focused probes and dual crystal probes. The diameter or side length of the probe is not greater than 25mm. This standard is applicable to the determination of probes for testing forged or rolled steel, aluminum alloy or titanium alloy products. This standard applies to the probe frequency range from 1MHz to 15MHz. 1MHz to 5MHz is most suitable for the detection of steel products, and 5MHz to 15MHz is most suitable for the detection of fine grain structure products such as aluminum alloys. If this standard is used for testing products other than steel, the user should be aware that the sound velocity in the product is different from that in steel, and the angle probe is usually designed for steel application. Snell's law given in this standard is intended to allow the user to calculate the exact angle of refraction in other materials. This standard applies to all practical refraction angle ranges (0°～70°). Also suitable for focus probes and dual element probes. This standard does not apply to surface wave probes. The methods given in this standard can be adopted as a whole, or partly when used together with other standards. When testing thicker or thinner materials, the test blocks recommended by this standard (HS and SDH test blocks) can also be increased or decreased accordingly. This standard does not consider the evaluation of the equivalent size of flaws that require the use of flat-bottomed hole test blocks to determine. This standard has no acceptance criteria. Of course, this standard has laid a technical foundation for users to formulate acceptance criteria.

GB/T 18852-2002 history

• 2020 GB/T 18852-2020 Non-destructive testing—Ultrasonic testing—Reference blocks and test procedures for the characterization of contact probe sound beams
• 2002 GB/T 18852-2002 Ultrasonic non-destructive testing--Reference blocks and test procedures for the characterization of contact search unit beam profiles