NS315

NS315 alloy is an austenitic nickel-based corrosion-resistant alloy containing 30% Cr. It not only has excellent stress corrosion cracking resistance compared to Inconel 600, Inconel 800, and 304 stainless steel in solutions containing chloride and sodium hydroxide, but also has high strength, good metallurgical stability, and excellent processing characteristics. In particular, NS315 alloy shows low corrosion rates and excellent stress corrosion resistance in various types of high temperature water. These properties are well suited for nuclear waste handling units, steam generators, and nitric acid resistant components.

NS315 alloy has excellent resistance to intergranular corrosion and intergranular stress corrosion cracking and is mainly used as heat transfer tube material for steam generators in pressurized water reactor nuclear power plants. Materials for heat transfer tubes for steam generators in pressurized water reactor nuclear power plants have gone through a development process, including 304 austenitic stainless steel, INCONEL 600 alloy, 800 alloy and NS315 alloy. The corrosion failure study of 600 alloy in service shows that intergranular corrosion and intergranular stress corrosion cracking is the main problem. NS315 alloy as a pressurized water reactor nuclear power plant steam generator heat transfer tube material, from the 1990s into service has not been found since the report of the breakage.