32Mn-7Cr AUSTENITIC STEEL FOR CRYOGENIC APPLICATIONS.

Abstract

Large superconducting magnets used for magnetic fusion energy systems require structural alloys with high yield strength and sufficient toughness at very low temperatures. Most of the present large superconducting magnets use nitrogen-strengthened austenitic stainless steels such as types 304LN, 304N, and 316LN. Nitrogen addition is very effective in strengthening austenite. Based on the extensive studies on the effects of chemical composition on low temperature mechanical properties. This study found 32Mn-7Cr austenitic steel to have high yield strength, improved toughness, and very stable austenite at liquid helium temperature.