Tensile Properties and Deformation-Induced Transformations in Metastable Austenitic Single Crystals.

摘要

Single crystal tensile specimens of Fe-15Cr-15Ni (wt. percent), a metastable austenite,have been made in four different tensile orientations and strained to fracture at two temperatures between M/sub d/and M/sub s/. The amount of transformation to strain-induced bcc martensite which proceeds concurrently with plastic strain is recorded at each orientation. The specimens tested at the lower temperature exhibit a higher strain-hardening rate and a much higher rate of transformation to martensite with strain than specimens of identical orientation strained at a temperature 80exp 0 C higher. The strain-hardening behavior of those specimens tested at the lower temperature,with significant martensitic transformation occurring,is seen to be a combined effect of normal fcc,orientation-dependent strain-hardening behavior (as exhibited by the specimens tested at the upper temperature) and the superposition of strain-hardening behavior due to the presence of the harder martensitic phase. (ERA citation 02:043694)