EFFECT OF NITROGEN ON THE MECHANICAL-PROPERTIES OF FE-CR-MN STEELS FOR CRYOGENIC APPLICATIONS

The effect of nitrogen content of Fe-Cr-Mn steels on their mechanical properties at room and cryogenic temperatures is studied. Chromium con tent of steels varied from 0 to 18%, manganese content, from 20 to 40% . One series of alloys contained 0.05-0.08% nitrogen, the other, 0.3-0 .5%. Alloying with nitrogen significantly increases the yield strength , especially at cryogenic temperatures. In nitrogen alloyed steels the room temperature impact strength is increased, but decreased at cryog enic temperatures, though still maintaining a high level. The composit ion of alloys possessing an optimal combination of mechanical properti es at cryogenic temperatures is determined.