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Various contributors have been suggested so far to explain the variation of mechanical properties of Fe–Co–V magnetic alloys, but a comprehensive understanding is still lacking. In the present study, the variation of hardness, tensile yield strength (YS), and elongation at room temperature were determined for an 86% cold-rolled Fe–50Co–10V (wt.%) alloy after annealing at the temperature range of 300–1050 °C for holding times from 10 to 240 min. The potential contributing factors were analyzed and discussed. Detailed microstructural evolution and magnetic properties have been reported earlier for this alloy. The results showed an increase in hardness and YS but a reduction in elongation after annealing at temperatures between 450 and 550 °C for all holding times. The activation energy of the contributing process in increasing the hardness after annealing between 300 and 550 °C was 132–144 kJ/mol, being a typical value for the ordering transition in ferrite in Fe–Co and Fe–Co–2V alloys. The YS increased up to an annealing temperature of 450 °C, followed by a decreasing trend at higher annealing temperatures even in the ordered state, obviously due to i) the recovery and recrystallization of ferrite, ii) decreasing the number of (Co,Fe)₂V precipitates and iii) increasing fraction of retained austenite. The elongation decreased to nil after annealing at 450–550 °C, but it was improved even in the ordered state at 600 °C and above due to the same factors which decreased the YS. The intergranular failure mode after annealing below 600 °C converted to ductile mode at 650 °C. Considering the combination of mechanical and magnetic properties, the annealing treatment at 650 °C for 10 min can be recommended for this alloy, providing high YS, a few percent elongation, and high magnetic hardness.

Thermomechanical processing consisted of hot-rolling in the austenitic region with deformation both above and below the non-recrystallization temperature. Immediately after rolling, specimens were directly quenched in water to three different temperatures of 560 °C, 420 °C and room temperature. The first two samples, which were quenched to 560° C and 420°C, immediately cooled slowly in the furnace. The microstructure of samples quenched to 560 °C mostly comprised of upper bainite whereas the samples quenched to 420 °C mainly consisted of lath-type bainite. The microstructure of sample direct-quenched to room temperature was mainly martensite. The transformation texture of all samples at the midthickness position showed the same general texture, consisted of mainly ᵅ and ᵞ fibers components with high intensities close to the transformed copper {112}<110>ᵅ, transformed brass {111}<112>ᵅ and rotated cube {001}<110>ᵅ components. However, the direct-quenched sample produced slightly more intense texture compared to the bainitic samples. The local texture of samples near the rolled surface owing to sever deformation showed the shear features consisting of major components of {112}<111>ᵅ, {110}<112>ᵅ and {110}<111>ᵅ.

Even after extensive research for decades on cold-rolled magnetic Fe–Co–V alloys, many aspects of ferrite recrystallization are still unclear. In order to analyse the progress of recrystallization in an Fe–50Co–10 V (in wt.%) alloy, different thermal cycles were conducted for an 86% cold-rolled thin sheet (∼140 μm). A comprehensive phase characterization and texture analysis were carried out using X-ray diffraction and scanning electron microscopy. To investigate the ferrite recrystallization during concurrent ordering and austenite transformation processes, the utilization of several methods such as the Kernel Average Misorientation and Grain Orientation Spread analyses together with grain boundary misorientation and grain size distributions, and characterization of microstructure by electron backscatter diffraction were crucial. The austenite transformation, detected to start at 500–550 °C, complicated the determination of the recrystallization kinetics; however, it was clarified by the present multi-parameter analyses. The ferrite recrystallization was found to initiate at 600 °C within 1 h and progress by the continuous recrystallization mechanism. The typical gamma-fiber texture of the cold-rolled alloy remained almost unchanged upon annealing temperatures up to 750 °C, also confirming the continuous recrystallization mechanism, similarly as the grain boundary misorientation evolution did. The recrystallization kinetics was found to follow the Avrami model with constant exponent in both ordered and disordered states. The recrystallization rate was slow, so that even after 4 h annealing in the disordered state at 750 °C, fragments of ferrite grains with straight sub-boundaries were retained.