抄録
Measurements of Young’s modulus at −150∼400°C and of rigidity modulus, thermal expansion and hardness at room temperature have been carried out for Mn–Ni–Fe alloys subjected to differing procedures of heat treatment and cold working. These measurements confirm that an anomalous change associated with the antiferromagnetic\
ightleftarrowsparamagnetic transformation appears on the Young’s modulus vs temperature curves for the ternary alloys slowly cooled after heating at 950°C for 1 hr. The Young’s modulus and rigidity modulus at room temperature does not indicate any remarkable difference by the various heat treatments, but its value shows the tendency to increase with increasing manganese or iron content. The temperature coefficients of Young’s modulus and rigidity modulus depend largely on the procedure of cold working and heat treating and also on composition. The existence of pronounced positive maximum values of temperature coefficients of Young’s modulus and rigidity modulus against composition reveals the Elinvar characteristics of the ternary alloys. The dependence of hardness on the various treatments and composition is complex. It is shown that the corrosion resistance of Mn–Ni–Fe alloys are fairly large.
