Corrosion Behaviour and Nickel Release of Alloys with Various Nickel Contents

Abstract

According to various statistics, up to 20 % of the population, particularly women, suffer an allergic reaction to nickel. Usually the reaction triggered by contact with Ni-plated materials used in jewellery, spectacle-frames, rivets etc.In many countries the authorities concerned have reacted to protect those people affected by introducing legislation. The interpretation of the legislation however often leads to uncertainty about the appropriate use of corrosion resistant materials containing nickel. The current work attempts to measure, in close to real conditions, the Ni-release of various materials and to evaluate the results.As was expected the Ni-release was found to primarily correlate to the corrosion behaviour of the materials however. Ni based alloys tested for comparison, which are usually used in the most corroding environments, were found to have a high Ni-release under skin contact simulating conditions.In addition to the corrosion tests, batch tests were also carried out on various steel grades.Particular attention was paid to a newly developed steel which shows excellent corrosion properties due to its alloy-design: Ni-free with high Cr, Mo and N-content and the use of C as an alloying element. Excellent mechanical and technological properties should also allow the use of this steel (Böhler P558) for medical implants.