EFFECT OF MANGANESE AND NITROGEN ON MECHANICAL-PROPERTIES OF FE-18 PERCENT CR-10 PERCENT NI STAINLESS-STEELS

Four series of 18Cr-10Ni steel were investigated containing, respectively, 0. 15N-xMn, 0. 30N-xMn, 4Mn-xN, and 8Mn-xN. The Mn range was 0 to 30% and the N range 0 to 0. 35%. Manganese was found to reduce yield strength, tensile strength, and elongation slightly; nitrogen increased yield and tensile strengths but decreased ductility. Manganese decreased the Charpy value in pure stable austenite, but the formation of martensite caused a pronounced drop in the energy absorbed in the Charpy test. The impact value above minus 100 C was increased by increasing nitrogen but decreased at minus 196 C. The effect of Mn and N on stacking fault energy was also determined.