Effect of Si and Mn Interactions on the Spheroidization and Coarsening Behavior of Cementite During Annealing in Severe Cold-Drawn Pearlitic Steel.

The effects of Si and Mn interactions on the spheroidization and coarsening behavior of cementite during annealing in severe cold-drawn pearlitic steel were studied. Spheroidization of cementite particles annealed at 873 K (600 °C) in heavily cold-drawn pearlitic steel was obviously retarded by higher Si contents. The coarsening kinetics of cementite particles in heavily cold-drawn and annealed pearlite obeyed a power-law relationship. The values of ECD increase steadily according to a temporal dependence of n (0.21 ± 0.02) for S87B and n (0.23 ± 0.06) for S87BM. The n values lie between 0.20 and 0.25, indicating that cementite particles coarsening occurs through a combination of dislocation diffusion ( n = 0.20) controlled and grain boundary diffusion ( n = 0.25) controlled coarsening mechanisms. Higher Si content in S87BM led to more pronounced partitioning of Mn than that in S87B, resulting in more significant suppression of alloying elements and lower coarsening rate constant K on the cementite particles coarsening behavior. [ABSTRACT FROM AUTHOR]