Pitting corrosion of stainless steels and high-alloyed Fe/Ni/Cr/Mo materials - Stages of development and test methods

In relation to the stages of development of pitting the characteristics and factors of influence are explained. After the explanation of distinct pitting potentials different ways of the detection of the stages of pitting are highlighted and their influencing through characteristic features of the metal, of the chemical composition of the medium, and of the physical conditions are pointed out. Based upon these facts, loading and methods of analyses and evaluation for the test of pitting resistance are discussed and chemical and electrochemical tests are described which are important to solve technical problems. Furthermore a test for the determination of the pitting resistance of welds directly performed at apparatus and equipments is explained which is still in the development stage.