Estimating the depth of surface flaws by penetrant testing

Experimental dependences are provided for the time growth of the areas of the indications of surface dead-end and through flaws with openings of 1–15 μm and depths of up to 12 mm during development under penetrant testing of stainless steel samples. A technique is proposed for estimating the depth of the surface flaws using the first derivative of the dependences 100 s after the beginning of development.