Hot deformation of AISI 414 martensitic stainless steel was studied over the temperature and strain rate intervals of 950−1150 °C and 0.001 to 1 s⁻¹, respectively. Based on the extracted data from hot compression tests a hyperbolic sine constitutive equation with correlation coefficient (R) of 0.99 was developed to model the flow behavior. The dynamic materials model (DMM) was used to establish the three-dimensional (3D) processing maps as a function of deformation temperature, strain rate, and strain. The analysis of the maps revealed that applied strain had a significant effect on power dissipation efficiency (η) and flow instability (ξ). Based on the generated processing maps four domains with the highest value of η were identified which represent the safe regions for hot working. Microstructural observation showed the significant effects of the temperature and strain rate on grain size evolution during hot deformation. From the microstructure analysis, the optimum hot working conditions were determined to be in the 1000−1130 °C temperature and 0.1–1 s⁻¹ strain rate ranges. Dynamic recrystallization was identified as the dominant restoration mechanism under these conditions. The influence of carbides on size of the dynamic recrystallized grain was also studied and correlated with grain size evolution. On the basis of the obtained results, a correlation between the dynamically recrystallized grain size and Zener–Hollomon parameter is proposed.

研究了AISI 414马氏体不锈钢在950-1150°C和0.001至1 s ^-1的温度和应变速率区间内的热变形， 分别。基于从热压缩测试中提取的数据，建立了相关系数（R）为0.99的双曲正弦本构方程，以对流动特性进行建模。动态材料模型（DMM）用于建立三维（3D）处理图，该图是变形温度，应变速率和应变的函数。这些图的分析表明，施加的应变对功耗效率（η）和流动不稳定性（ξ）有显着影响。根据生成的处理图，确定了四个具有最高η值的域，它们代表热加工的安全区域。显微组织观察表明，温度和应变速率对热变形过程中晶粒尺寸的变化有显着影响。从微观结构分析^-1应变率范围。在这些条件下，动态再结晶被确定为主要的恢复机制。还研究了碳化物对动态再结晶晶粒尺寸的影响，并将其与晶粒尺寸演变相关。根据获得的结果，提出了动态再结晶晶粒尺寸与Zener-Hollomon参数之间的相关性。