Influence of warm deformation on the formation of a fragmented structure in low-carbon martensitic steels

• Published in: Physics of metals and metallography 2016, Vol.117 (1), p.61-73
• Main Authors: Tabatchikova, T. I., Yakovleva, I. L., Delgado Reina, S. Yu, Plokhikh, A. I., Ospennikova, O. G., Gromov, V. I.
• Format: Article
• Language: English
• Subjects: Alloys; Boron steel; Chemistry and Materials Science; Deformation; Diffusion; Formations; Martensitic stainless steels; Materials Science; Metallic Materials; Phase Transformations; Recrystallization; Rolling; Specialty steels; Steel alloys; Structure; Upsetting; Warm rolling; Warm working
• ISSN: 0031-918X; 1555-6190
• DOI: 10.1134/S0031918X16010117

Methods of optical metallography and scanning and transmission electron microscopy were used to investigate the structure of low-carbon steels of martensitic classes VKS-7 and VKS-10 subjected to warm rolling or upsetting at temperatures of 600 and 700°C (in the α state) and 800°C (in the γ state). It has been shown that the deformation by rolling at 600°C to degrees of 40 and 60% does not lead to the destruction of the lath structure of the initial martensite; an increase in the rolling temperature to 700°C and of the degree of deformation to 80% favors the development of recrystallization in situ. It has been found that, upon warm deformation by upsetting, recrystallization occurs at lower temperatures than in the case of the warm rolling. It has been shown that warm deformation by upsetting at a temperature of 700°C leads to the formation of a fragmented structure with a high fraction of ultrafine grains with a size less than 2 μm.