D. A. Cortés

Effect of nitrogen on the microstructure and mechanical properties of a CoCrMo alloy

Abstract The effect of nitrogen on the microstructure and mechanical properties of a cobalt base alloy was studied. The treatments were carried out for contact times of 0, 15, 30, 45 and 55 min, between the gas the liquid metal. The treatment temperature was 1723 K at a nitrogen pressure of 0.67 atm. The results showed that as the nitrogen content increased, the tensile and fatigue strengths increased, the hardness increased slightly and the ductility decreased. The metallographic analysis showed that the nitrogen content had little effect on the grain size. When the nitrogen content in the alloy was increased, the formation of finer carbides of the M6C type was promoted ahead of the M23C6 type. The fine carbides tended to accumulate along the grain boundaries.