Investigation into Hot Deformation Behavior and Processing Maps of 14CrMoR High-Performance Vessel Steel

14CrMoR steel, possessing excellent low-temperature impact toughness and corrosion resistance, is an important material for core equipment in the coal chemical industry. In this paper, 14CrMoR steel was subjected to single-pass compression tests at deformation temperatures ranging from 900 to 1150 °C and strain rates of 0.1, 1, 5, and 10 s−1. The hot deformation behavior and constitutive relationship were investigated. The strain rate sensitivity factor m, power dissipation coefficient η, and instability parameter ξ were calculated, respectively. A power dissipation map was plotted, and a hot processing map was established. The results showed that the stress of 14CrMoR steel increased with the decrease in deformation temperature and the increase in strain rate. Dynamic recrystallization was likely to occur at high deformation temperatures and low strain rates. When the strain rate was 10 s−1, in the temperature range of 900–950 °C, the power dissipation rate was the lowest. With the increase in temperature, the power dissipation rate rose, and the maximum power dissipation rate was reached in the temperature range of 1100–1150 °C. The research on the hot deformation behavior of 14CrMoR steel has important guiding significance for the design and optimization of the process.