New High Nitrogen Super Austenitic Stainless Steel With Improved Corrosion Resistance in Oxydizing Chloride Environments, 1995 Engineering Conference Proceedings

Jean-Pierre Audouard

Creusot-Loire Industrie

Jacques Charles

Creusot-Loire Industrie

A new 6Mo super-austenitic stainless steel has been developped on the account of investigations performed on a series of high nitrogen alloys containing high molybdenum, chromium, nickel and complementary additions of tungsten and copper. These investigations showed the highest alloyed MO-N grades to achieve a very high corrosion resistance including pitting and crevice but their structural stability appeared to be unsufficient to permit the development of industrial products . Tungsten addition has proved very useful1 from a corrosion point of view in replacing a certain amount of MO while the structural stability was found to be better than for the highest MO grades. As a result, the paper discusses the properties of the new high nitrogen containing UR B66 stainless steel with special emphasis on structural stability, mechanical properties and corrosion performance in chloride containing media. From pitting and crevice corrosion tests on unwelded and welded specimens carried out in oxydizing chloride containing me-dia, the new UR B66 grade appears to be one of the best candidates for use in chlorine and chlorine dioxyde bleaching operations.