Papers by Keyword: ε Phase

Abstract: The martensite induced in three types of austenitic stainless steel, which indicate the different stability of the austenitic phase (γ), were estimated by the resistivity measured during the tensile deformation or compressive deformation at the temperatures 77, 187 and 293 K. The resistivity curves were strongly dependent on the deformation mode. The volume fraction of the martensite (α’) was also affected by the deformation mode. The ε phase, which is the precursor of the martensite and is induced from the commencement of the deformation, decreased the resistivity. However, lots of defects generated by the deformation-induced martensite increased the resistivity. The experimental facts and the results shown by the modified parallelepiped model suggested a complicated transformation process depending on each deformation mode. The results shown by the model also suggested a linear relation between the resistivity and the martensite volume at the region of the martensite formation. The fact denoted that the resistivity is mostly not controlled by the austenite, ε phase and martensite, but by the defects induced due to the deformation-induced martensite.

Abstract: Based on the recent requirements, high strength, high damping stainless alloy HIDAS was developed. The chemical compositions are Fe-12%Cr-22%Mn and Fe-12%Cr-22%Mn-2%Co. After solution annealing, microstructure consisting of austenite fcc
, martensite hcp  and bcc ’. When cold work was given,  and  increased. Damping capacity increased with the increase of  phase. The mechanism of high damping capacity would come from the hysteretic motion of Shockley partial dislocations which are lying at interphase interface of /
. This alloy has also high strength. This is due to fine structure of /
. Because of these properties, HIDAS can be applied to machinery industries.