Mechanisms of Grain Structure Evolution in a Quenched Medium Carbon Steel during Warm Deformation

oleh: Dmitriy Panov, Olga Dedyulina, Dmitriy Shaysultanov, Nikita Stepanov, Sergey Zherebtsov, Gennady Salishchev

Format: Article
Diterbitkan: MDPI AG 2020-06-01

Deskripsi

The as-quenched medium-carbon low-alloy Fe-0.36wt.%C-1wt.%Cr steel was subjected to warm deformation via uniaxial compression at temperatures of 400–700 °C and strain rates of 10<sup>−4</sup>–10<sup>−2</sup> s<sup>−1</sup>. At low temperatures (400–550 °C), the microstructure evolution was mainly associated with dynamic recovery with the value of activation energy of 140 ± 35 kJ/mol. At higher temperatures (600–700 °C), dynamic recrystallization was developed, and activation energy in this case was 243 ± 15 kJ/mol. The presence of nanoscale carbide particles in the structure at temperatures of 400–600 °C resulted in the appearance of threshold stresses. A two-component <001>//compression direction (CD) and <111>//CD deformation texture was formed during deformation. Deformation at the low temperatures resulted in the formation of elongated ferritic grains separated mainly by high-angle boundaries (HAB) with a strong <001>//CD texture. The grains with the <111>//CD orientation were wider in comparison with those with the <001>//CD orientation. The development of substructure in the form of low-angle boundaries (LAB) networks was also observed in the <111>//CD grains. The development of dynamic recrystallization restricted the texture formation. The processing map for warm deformation of the 0.36C-1Cr steel was constructed.