Microstructure Prediction of 316LN Stainless Steel for Dynamic Recrystallization Based on Cellular Automata

Abstract

The established cellular automata model of dynamic recrystallization for 316LN simulated microstructure evolution of recrystallization nucleation and grain growth under different conditions. And on the basis of cellular automata model, the influence of strain, strain rate, deformation temperature on dynamic recrystallization behavior was analyzed. Though the hot compress experiment done on the Gleeble-3500 thermo mechanical simulator, combined with metallographic experiment, the microstructure at deformation temperature of 950 oC, 1050 oC and 1150 oC with strain rate of 0.001 s-1, 0.01 s-1, 0.1 s-1 and 1 s-1 was obtained. Simulation results are compared with metallographic microstructure, the error is small.

Dynamic Recrystallization and Hot Workability of 316LN Stainless Steel

“…Figure 4a shows the relationship between ε c and ε p , and it is similar to the result studied by Ji [26]. Figure 4b shows the method to identify the saturation stress σ sat and the steady flow stress σ ss due to the dynamic recrystallization: the intersection point where a tangent line at the critical strain point cuts the x-axis (θ = 0) is the σ sat ; the intersection point of the lower value where the σ-θ curve cuts the x-axis (θ = 0) is the σ ss [27,28].…”

“…But in the practical hot deformation of the material, the strain rate does not change significantly during the process, especially in tube extrusion and bar extrusion processes. Therefore, it is necessary to construct an updated hot processing map according to Equation (26) which reveals the relationship of the variation of the power dissipation efficiency with the increase of the strain (shown in Figure 9). In Figure 9a, there are some shaded areas which are inappropriate for processing, so it is practical to avoid these regions to control the microstructure evolution through reining in the temperature during the process.…”