凝固速度对Fe-Cr-C原位生长复合材料定向凝固组织的影响
摘要
It was studied that the effect of solidification rate on the solidification structure of high chromium cast iron with the composition of Fe-3.35% C-27.5% Cr, by unidirectional solidification of liquid metal cooling with directional contribution of carbides formed in situ. The results show when he temperature gradient at the solidification front is about 150 K/cm and solidification rate is in the range of 1 and 10 μm/s, Fe-Cr-C in situ composites can be manufactured successfully. The morphology of primary phase M7C3-type carbides cross section is hexagonal and hollow hexagonal at he high solidification rate, and with decrease of solidification rate, the morphology of primary phase Dross section tends to be in U and L shape. Although the morphology of eutectic carbide M7C3 is relatively regular, the detailed structure of the eutectic carbides forms many branches, and with the increase of solidification rate, branching will become more remarkable.