| Title |
The Effect of Cooling and Strain on Martensitic Transformation in Fe - Ni - Cr - Mn - Si Alloy |
| Authors |
박신화(Shin Hwa Park); 남원종(Won Jong Nam); 윤만순(Man Son Yoon); 강신왕(Shin Wang Kang); 이도형(Do Hyung Lee) |
| Abstract |
In Fe-Ni-Cr-Mn-Si shape memory alloy, the effect of cooling methods and strain on the martensitic transformation was investigated. After the solution treatment at 900℃ for 30 minutes, the specimens were air cooled, water cooled and quenched in liquid nitrogen. For air cooled specimens only austenite phase was detected, whereas austenite and ε-martensite phases were detected for specimens water cooled or quenched in liquid nitrogen. The amount of ε-martensite was increased with the cooling rate and strain. But the increasing rate of the amount of ε-martensite was decreased at 5% strain in air cooling and at 3% strain in water cooling, respectively. The occurrence of α`-martensite was found at about 5% strain in air cooled specimens. For water cooled specimens it was found at about 3% strain. These strains almost coinceded with the strains at which the increasing rate of the amount of ε-martensite was changed. The occurrence of α`-martensite in specimens quenched in liquid nitrogen was found less than 0.5% strain. |