New Corrosion-Resistant Bactericidal Nitrogen-Containing Steels with Increased Strength
The new high-strength stainless steels alloyed by copper and nitrogen and possessing high resistance to corrosion by active micro-organisms in carbon-oxidizing, heterotrophic and sulfate-regenerating bacteria mediums are developed. The introducing of small addition of nitrogen (about 0.22 %) to the corrosion resistant steel С0.5Cr15Ni5Cu2NMoNbTi results in a decrease of adhesive micro-organisms quantity on a sample surface by 8 times, while increasing of nickel content to 9 % results in their decrease only by 2 times. It is supposed that the effect of nitrogen can be related to formation of biocide substances. High copper (Cu = 2.5-5 %) nitrogen-containing cast steels are in austenitic (non-magnetic) condition. Due to a dendritic segregation, the structure of steel corresponds to a natural composite structure, and it is preserved on heating to high temperatures. After cold deformation with up to 85 % reduction, the steels preserve austenitic structure, and its hardness attains a level close to the hardness level of the martensitic structure. The developed corrosion-resistant antimicrobial steels with the increased hardness can be used as a material for the surgical instrument.
Pietro VINCENZINI, John A. JANSEN, Kazuhiko ISHIHARA and Thomas J. WEBSTER
L. M. Kaputkina et al., "New Corrosion-Resistant Bactericidal Nitrogen-Containing Steels with Increased Strength", Advances in Science and Technology, Vol. 76, pp. 72-77, 2010