Effects of annealing temperature on microstructure and mechanical behavior of conventionally and severely deformed Fe–24Ni steel by accumulative roll bonding

Abstract

In this research, the effects of annealing temperature (500, 550, and 600 °C) on the microstructure and mechanical properties of a conventionally (1 cycle) and severely (6 cycles) deformed Fe–24Ni martensitic steel, processed by accumulative roll bonding (ARB), were investigated. Electron backscattered diffraction (EBSD) analysis revealed that annealing at 500 and 550 °C for 30 min was insufficient for completing the reverse martensite transformation, and consequently, the microstructure consisted of austenite and martensite. However, complete reverse martensitic transformation has been accomplished after annealing at 600 °C for 30 min for both deformed samples. Both yield strength (YS) and ultimate tensile strength (UTS) were increased after first and sixth cycle of rolling. Subsequent, annealing led to a decrease in YS and UTS with improvement in uniform elongation (eu). In addition, the work hardenability was also improved by annealing the deformed samples.

Keywords

• Fe–24Ni
• Martensitic steel
• ARB
• Reverse martensite transformation
• Work hardenability