Plastic deformation and transformation of a steel

• Published in: Physica B + C 1986, Vol.139, p.754-757
• Main Authors: Kaieda, Yoshinari, Oguchi, Atsushi
• Format: Article
• Language: English
• ISSN: 0378-4363
• DOI: 10.1016/0378-4363(86)90693-5

Mechanical properties of the usual metallic materials such as yield stress, stress-strain curve and uniform-strain limit are scarcely affected by hydrostatic pressure. However, tensile tests of a 17Cr7Ni1Al steel, which was a strain-induced transforming material, were carried out at 0.1, 300 and 600 MPa hydrostatic pressure, and the mechanical properties of the material were found to be considerably changed by the pressure. The martensitic transformation temperature, M s γ→α', decreased under pressure. The volume fraction of α-martensite induced by tensile deformation increased with strain, but was suppressed by hydrostatic pressure. The yield stress increased with presure. The relationship between yield stress and hydrostatic pressure was expressed by a yield function. The stress-strain curve was strongly changed by pressure. The uniform-strain limit increased with hydrostatic pressure. It was found that these changes were not caused by the mechanical effect of hydrostatic pressure, but by its thermodynamic effects.