Study of Hardness and Structural Features of Hot-Rolled Chromium Vanadium Structural Steel after Cyclic Spheroidizing Annealing

The effect of a newly developed temperature regime for cyclic annealing on changes in the microstructure and hardness of hot‑rolled structural steel 40KhFA is examined, taking into account the characteristics of the initial ferrite–pearlite structure. Based on studies of the distribution of carbide phases in the annealed steel under consideration, it was concluded that it is impossible to obtain a 100% granular pearlite structure. The new cyclic annealing regime makes it possible to achieve additional microstructure and hardness characteristics for annealed rolled stock that differ from those specified in State standard GOST 4543–2016, and demonstrates the advisability of its further application in modern metallurgical production.