Penetration testing (PT) is used to detect welding defects appearing on the surface of the material (open discontinuities). This method is used for testing non-metallic and metallic materials with ferromagnetic, paramagnetic and diamagnetic properties. In practice, it is not used only in examining high porosity materials.
Before the commencement of the test, the surface of the inspected specimen should be dried and cleaned thoroughly, after which dye penetrant should be applied, which penetrates the discontinuities and gaps in the inspected materials using the capillarity principle. After a specified time, excess penetrant should be removed from the tested surface with a remover product so that it only remains inside the surface discontinuities, and the developer product should be applied. The developer will absorb the penetrant that has penetrated and remained in the discontinuities so that the indication is prominent and enlarged.
The penetration method can only be used to discover leakage in the inspected specimen. Leak testing consists of applying penetrant on one side of the test specimen and developer on the other side. If there is leakage in the specimen, color indications present on the developer application side.
The reagent kits used for penetration testing consist of:
- dye or fluorescent penetrant (in dye penetration and fluorescent penetration technique),
- remover,
- developer.
Penetration testing is performed in conformity with the following standards:
PN-EN ISO 12706:2010 - Non-destructive testing — Penetrant testing — Vocabulary
PN-EN ISO 3059:2013-06 - Non-destructive testing — Penetrant testing and magnetic particle testing — Viewing conditions
PN-EN ISO 23277:2015-05 - Non-destructive testing of welds — Penetrant testing — Acceptance levels
PN-EN ISO 3452-1:2021-12 - Non-destructive testing — Penetrant testing — Part 1: General principles
PN-EN ISO 3452-2:2021-12 - Non-destructive testing — Penetrant testing — Part 2: Testing of penetrant materials
PN-EN ISO 3452-3:2014-02 - Non-destructive testing — Penetrant testing — Part 3: Reference test blocks
PN-EN ISO 3452-4:2001 - Non-destructive testing — Penetrant testing — Part 4: Equipment
PN-EN ISO 3452-6:2009 - Non-destructive testing — Penetrant testing — Part 6: Penetrant testing at temperatures lower than 10 degrees C
PN-EN 10228-2:2016-07 - Non-destructive testing of steel forgings - Penetrant testing
PN-EN 1371-1:2012 - Founding - Liquid penetrant testing - Part 1: Sand, gravity die and low pressure die castings
PN-EN 1371-2:2015-03 - Founding. Liquid penetrant testing - Investment castings
PN-EN ISO 10893-4:2011 - Non-destructive testing of steel tubes. Liquid penetrant inspection of seamless and welded steel tubes for the detection of surface imperfections
