준안정 오스테나이트강의 기계적성질과 감쇠능에 미치는 가공유기 마르텐사이트의 영향

Abstract

This study has been conducted to investigate the effect of deformation-induced martensite on the damping capacity and tensile property in Fe-Cr-Mn-Co alloy. Particularly, the phase of austenite, α' martensite, and εmartensite which were formed by cold rolling at room temperature was investigated. The results obtained from this study is summarized as follows; The phase of Fe-Cr-Mn-Co was consisted with austenite, α' martensite and ε martensite structure at room temperature. The volume fraction of austenite phase was decreased with an increase of degree of cold rolling. The volume fraction of ε martensite phase was decreased after rising to maximum value at specific level of cold rolling. The volume fraction of α' martensite phase was increased slowly and then dramatically increased form the point of decreasing of ε martensite volume fraction. The behavior of damping capacity was found to be similar to ε behavior of martensite volume fraction. After the damping capacity shows the maximum value, the damping capacity was decreased with the volume fraction of ε martensite. Damping capacity was strongly controlled by volume fraction of ε martensite with linear relationship, while the effect of the volume fraction of α' martensite on damping capacity was not observed. With increasing the degree of cold rolling in Fe-Cr-Mn-Co alloy, tensile strength was proportional to the volume fraction of α' martensite and elongation was decreased. Tensile strength was strongly affected by the volume fraction of α' martensite.