Elastic Anisotropy and Its Temperature Dependence of Single Crystals and Polycrystal of 18–12 Type Stainless Steel

Measurements of thermal expansion and Young’s modulus at −150°∼500°C have been carried out with single crystal specimen, 3 mm in diameter and 12 cm long, of 18–12 type stainless steel. At the same time the rigidity modulus of a polycrystal specimen was measured at room temperature. At 20°C the Young’s moduli determined are 10.34×105, 21.00×105 and 32.00×105 kg/cm2 in the 〈100〉, 〈110〉 and 〈111〉 directions, respectively, while the rigidity moduli are 14.13×105, 5.92×105 and 6.70×105 kg/cm2 in the three principal directions, respectively. In both cases, the elastic anisotropies are very large. The Young’s moduli in the three principal directions decrease monotonously with temperature. The mean temperature coefficients of Young’s modulus at 0°∼40°C in the three principal directions are e〈100〉=−51.70×10−5, e〈110〉=−37.80×10−5 and e〈111〉=−24.90×10−5, respectively.