Effects of High Pressure on the Strength and Structure of Martensites

Abstract

FOLLOWING the direct observation of fine-scale twinning (∼ 100 Å spacing) in the martensitic structures formed by the rapid quenching of certain steels and other alloys¹, relationships between the incidence of twinning and the high mechanical strength of martensites have been postulated, explicitly in a qualitative strengthening model² and implicitly in a quantitative solution-hardening model³. In view of the suggested importance of the twinning contribution to strength, an attempt has been made to test its validity by experiments on martensitic transformations in the iron–carbon and iron–chromium systems at high pressure and in the iron–nickel system at atmospheric pressure. The experimental apparatus and techniques used have been described elsewhere⁴.