Mechanical Properties and Deformation Behavior in Severely Cold-Rolled Fe-Ni-Al C Alloys with Luders Deformation -Overview with Recent Experimental Results

It has been reported that severely cold worked Fe-24.6Ni-5.8Al-0.4C (mass%) had a yield strength of 2 GPa and a fracture elongation of 20%, in which huge amount of Luders-type deformation was observed. In the present article, we summarize the reports for high-strength Fe-Ni-Al -C, Fe-Mn, Fe-Cr-Ni and Fe-Ni-Mn base steels with the Luders-type deformation so far, and provide our latest data on the effects of alloying elements and the cold-rolling reduction on the microstructure and mechanical properties of cold-rolled Fe-Ni-Al -C alloys. Previous reports imply that the phase stability of & POUND;phase affects the size of Luders elongation, while the strategies to control the microstructure to achieve high strength and high ductility are currently unknown. Our latest study also shows that the & POUND;-phase stability affects the Luders strain. In addition, it is confirmed that severe cold rolling by 80% enables the prolonged Luders strain as much as 25% in nominal strain. This prolonged Luders strain is achieved by multiple propagation of Luders-type bands. [doi:10.2320/matertrans.MT-MF2022024]