The Marine Care Pasivation Test Kit is an easy and economical test kit to determine the Passiveness of austenitic stainless steel. Stainless steel is protected from corrosion by a thin layer that consists mainly of chromium oxide.
Oxygen from the atmosphere is normally able to form and maintain this passive layer. Contamination, surface defects and imperfections disturb the formation and repair of the chromium oxide layer and reduce the resistance to severe or local corrosion. Therefore it is very important to test if your stainless steel is still passive to prevent corrosion and damage.
The measure of passivation of stainless steel can be determined with a palladium chloride reagent. The reagent keeps colour on good passivated stainless steel. A black spot will appear when the surface has not been passivated correctly. Various qualities of passivation will give graduations of grey shades, ranging from light (acceptable) to dark (unacceptable).