Liquid Penetrant Testing

Liquid penetrant testing is a non-destructive surface inspection method that uses highly permeable liquid to penetrate into the surface defect of the component, and then try to make it show the defect. According to the different penetrants used, it can be divided into colored penetrating method and fluorescent penetrating method.

STEMart provides liquid penetrant testing for surface quality detection of non-porous materials (such as metal, plastic, glass, ceramic and steel parts).

Test Procedures

• Pre-cleaning: Before the liquid penetrant is applied, all surfaces to be inspected should be clean, dry and free of dirt, grease, paint and other coatings.
• Penetration: Unless otherwise specified, the entire surface of the part should be covered with penetrant. The penetrant is applied by spraying, dipping or other methods to provide the required coverage.
• Removal of excess penetrant: Water washing, emulsified water washing and solvent cleaning can be used.
• Drying: Remove surface moisture.
• Imaging: The thickness of imaging agent is 0.05mm-0.07mm, keep it for 10-15min.
• Observation: Observe with naked eye or magnifying glass under visible light, this method is suitable for coloring method, and ultraviolet lamp is suitable for fluorescence method.
• Evaluation.
• Post-clean: Remove residual penetrant and imaging agent.

Test Capabilities

Check of materials' surface opening defects in all directions and shapes, including cracks, porosity, pores, slag inclusion, cold insulation, folding, etc.

Test Material Types

• Metals
• Non-metallic materials
• Magnetic and non-magnetic materials
• Welded parts
• Castings

For more information about our liquid penetrant testing, please contact us.