Effect of titanium sulfide particles on grain size in low carbon steel

Abstract

The effect of titanium sulfide particles on the grain size characteristic of low carbon steel was analyzed. Optical microscope (OM), scanning electron microscope (SEM) were used to characterize the grain size and particles. The result showed that grain size increased from 19.95 to 60.56 μm after heat treatment. The particles were mainly titanium sulfide in the size range of 0.2–0.8 μm and the volume fraction decreased significantly from 0.0084 to 0.0023%. The thermodynamic calculation resulted that these particles were dissolved during heat treatment. The pinning force of grain boundary and the driving force of grain growth were calculated. Based on experimental results and theoretical calculations, titanium sulfide particles with diameter from 0.2 to 0.8 μm and volume fraction of 0.0084% would be sufficient to inhibit the ferrite grain growth.