Effect of titanium on the as-cast microstructure of hypereutectic high chromium cast iron

The effect of titanium on the as-cast microstructure of a hypereutectic high-Cr cast iron containing 4.0 wt.% carbon and 20.0 wt.% chromium was investigated. With the increase of titanium concentration, the primary M7C3 carbides were refined and the volume fraction of all carbides (primary and eutectic carbide) was decreased gradually. TiC particles became larger and agglomerated when the titanium concentration was 1.47 wt.%. Theoretical calculation and experimental results confirmed that TiC particles form before the precipitation of primary carbides. The first precipitated TiC particles can act as the heterogeneous substrate of M7C3 carbides, which results in significant refinement of M7C3 carbides.