GB/T 18851.1-2024 Non-destructive testing — Penetrant testing — Part 1: General principles
Non-destructive testing — Penetrant testing — Part 1: General principles
1 Scope
This document specifies a method of penetrant testing used to detect discontinuities, e.g. tracks, laps, folds, porosity and lack of fusion, which are open to the surface of the material to be tested using white light or UV-A (365 nm) radiation. It is mainly applied to metallic materials, but can also be performed on other materials, provided that they are inert to the test media and not excessively porous (castings, forgings, welds, ceramics, etc.)
This document also includes requirements for process and control testing, but is not intended to be used for acceptance criteria. It gives neither information relating to the suitability of individual test systems for specific applications nor requirements for test equipment.
Note 1: Methods for determining and monitoring the essential properties of penetrant testing products to be used are specified in ISO 3452-2 and ISO 3452-3.
Note 2: The term "discontinuity” is used in this document in the sense that no evaluation concerning acceptability or non-acceptability is included.
Note 3: CEN/TR 16638 addresses penetrant testing using actinic blue light.
2 Normative references
The following documents contain requirements which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 3059 Non-destructive testing - Penetrant testing and magnetic particle testing - Viewing conditions
Note: GB/T 5097-2020 Non-destructive testing - Penetrant testing and magnetic particle testing - Viewing conditions (ISO 3059:2012, IDT)
ISO 3452-2 Non-destructive testing - Penetrant testing - Part 2: Testing of penetrant materials
Note: GB/T 18851.2-2008 Non-destructive testing - Penetrant testing - Part 2: Testing of penetrant materials (ISO 3452-2:2006, IDT)
ISO 3452-3 Non-destructive testing - Penetrant testing - Part 3: Reference test blocks
Note: GB/T 18851.3-2008 Non-destructive testing - Penetrant testing - Part 3: Reference test blocks (ISO 3452-3:1998, IDT)
ISO 3452-4 Non-destructive testing - Penetrant testing - Part 4: Equipment
Note: GB/T 18851.4-2005 Non-destructive Testing - Penetrant Testing - Part 4: Equipment (ISO 3452-4: 1998, IDT)
ISO 3452-5 Non-destructive testing - Penetrant testing - Part 5: Penetrant testing at temperatures higher than 50°C
Note: GB/T 18851.5-2014 Non-destructive testing - Penetrant testing - Part 5: Penetrant testing at temperatures higher than 50°C (ISO 3452-5:2008, IDT)
ISO 3452-6 Non-destructive testing - Penetrant testing - Part 6: Penetrant testing at temperatures lower than 10°C
Note: GB/T 18851.6-2014 Non-destructive testing - Penetrant testing - Part 6: Penetrant testing at temperatures lower than 10°C (ISO 3452-6:2008, IDT)
ISO 12706 Non-destructive testing - Penetrant testing - Vocabulary
Note: GB/T 12604.3-2013 Non-destructive testing - Terminology - Terms used in penetrant testing (ISO 12706:2009, IDT)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 12706 apply.
4 Safety precautions
As penetrant inspection techniques often require the use of harmful, flammable and/or volatile materials, safety regulations (e.g. optical radiation legislation) shall be taken into account.
Prolonged or repeated contact of these materials with the skin or any mucous membrane should be avoided. Working areas shall be adequately ventilated and sited away from sources of heat, sparks or naked flames, taking into account all applicable safety regulations.
The penetrant testing products and equipment shall be used with care and always in compliance with the instructions supplied by the manufacturer.
UV-A sources shall always be maintained in a good condition.
Care shall be taken to ensure the safe implementation of the method.
5 General principles
5.1 Personnel
Testing shall be carried out by proficient, suitably trained and qualified personnel and, where applicable, shall be supervised by competent personnel nominated by the employer or, by delegation of the employer to the inspection company in charge of testing. To demonstrate appropriate qualification, it is recommended that personnel be certified according to ISO 9712 or an equivalent formalized system. Penetrant testing operations, unless otherwise agreed, shall be authorized by a competent supervisory individual (Level 3 or equivalent) approved by the employer.
5.2 Description of the method
Prior to penetrant testing, the surface to be inspected shall be clean and dry. Suitable penetrant is then applied to the test area and enter discontinuities open to the surface. After the appropriate penetration time has elapsed, the excess penetrant is removed from the surface and the developer applied. The developer absorbs the penetrant that has entered and remains in the discontinuities and may give a clearly visible enhanced indication of the discontinuity.
Should complementary non-destructive testing (NDT) be required, it is preferable that the penetrant inspection be performed first, so as not to introduce contaminants into open discontinuities. If penetrant inspection is used following another NDT technique or method, the surface shall be cleaned carefully to remove contaminants before application.
5.3 Process sequence
The penetrant process shall be continuous with no undue delays between the stages. If process parameters are not met, surfaces shall be cleaned and reprocessed.
Testing generally proceeds through the following stages:
a) preparation and precleaning (see 8.2);
b) application of penetrant (see 8.4);
c) excess penetrant removal (see 8.5);
d) application of developer (see 8.6);
e) inspection (see 8.7);
f) postcleaning and corrosion protection (see 8.8).
The process shall be as given in Annex A.
5.4 Equipment
Foreword II
Introduction V
1 Scope
2 Normative references
3 Terms and definitions
4 Safety precautions
5 General principles
6 Products, sensitivity and designation
7 Compatibility
8 Test procedure
9 Test report
Annex A (Normative) Main stages of standard penetrant examination
Annex B (Normative) Process and control tests
Annex C (Informative) Example test report
Bibliography
