Co-Fe-Cr 系合金の熱膨脹，剛性率およびその温度係数におよぼすNi添加の影響について（第2報）Ni 30%および40%の場合

Abstract

The influence of additions of 30 and 40 percent of nickel on thermal expansion in the range from 10° to 50°, rigidity modulus at 20° and its temperature coefficient in the range from 20° to 50°, of alloys of cobalt, iron and chromium has been determined. The relations between those properties of nickel-added alloys and the concentrations are qualitatively almost similar to those in the cases of the ternary alloys of cobalt, iron and chromium and of the alloys added with 10 and 20 percent of nickel; that is, there are two groups of alloys, one of which has a positive temperature coefficient of rigidity modulus and the other a negative, a zero coefficient boundary existing between them. The addition of nickel affects the coefficient of thermal expansion and the temperature coefficient of rigidity modulus of the ternary alloys, as if cobalt can be substituted by nickel; that is, the compositions, at which the thermal expansion coefficient shows the minimum value and the temperature coefficient of the modulus the largest positive, shift to the side of low cobalt content almost linearly with the addition of nickel and reach those in the binary alloy of iron and nickel. Further, if the quantity of nickel is increased, the concentration range having positive coefficients of the modulus becomes wider, and the slope of the latter to the concentration smaller. When the quantity of addition of nickel is 30 percent, the smallest value of the thermal expansion coefficient is 1.87×10−6 obtained with the alloy containing 21 percent of cobalt, 73 percent of iron and 6 percent of chromium, and when 40 percent of nickel is added, 0.54×10−6 obtained with the alloy containing 11 percent of cobalt, 87 percent of iron and 2 percent of chromium. In the case of an addition of 30 percent of nickel, the positive largest value of the temperature coefficient of rigidity modulus are +76.4×10−5 obtained with the alloy containing 21 percent of cobalt, 73 percent of iron and 6 percent of chromium and in the case of 40 percent of nickel +81.0×10−5 obtained with the alloy containing 13 percent of cobalt, 85 percent of iron and 2 percent of chromium. The largest and the smallest values of rigidity modulus in the case of an addition of 30 percent of nickel are 7.84×105 kg/cm2 in the alloy of 60 percent of cobalt, 20 percent of iron and 20 percent of chromium and 4.55×105 kg/cm2 in the alloy 37 percent of cobalt, 60 percent of iron and 3 percent of chromium, respectively, and in the case of 40 percent of nickel, they are 8.96×105 kg/cm2 in the alloy containing 0 percent of cobalt, 96 percent of iron and 4 percent of chromimum and 4.69×105 kg/cm2 in the alloy containing 25 percent of cobalt, 75 percent of iron and 0 percent of chromium, respectively.