Effect of Ti and Al etc. on Mechanical Properties of Nimonic 80A

Studies on nickel-base heat-resisting alloys-VI

Abstract

Effects of Ti, Al and gas content on stress-rupture characteristics at 750°C and 26.8kg/mm² were investigated. Stress-rupture life increased with an increase of Ti+Al atm% containing below 2.9% Tiand 1.44% Al. Elongation after stress-rupture was small and the effect of Ti and Al content on it was not clear. Stress-rupture life depends not only on the amount of Ti and Al but also on the amount of nitrogen and oxygen or hydrogen, which arises from the melting procedure and content of raw materials. As in the case of an iacrease of the amount of gas content causes the decrease of stress-rupture life remark ably, so the material vacuum-melted or the mterial which is air-melted after vacuum-melting have more stress-rupture life than the material air-melted from fresh raw material. As the fact that the increase of gas content causes much precipitate around grain boundary, and tends to soften the material during stress-rupture testing by overaging, so stress-rupture life decreases. Effect of micrtructure on stress-rupture life is presumably the same phenomena as heat treatments such as A and B to the effect of gas content.