Effects of rotational speed on the properties of centrifugally cast steel castings in metallic mold

摘要

The effect of rotational speed (time gravity) on the mechanical properties and microstructures of centrifugally cast steel has been studied. Four different times gravity, ie, 50G, 60G, 70G and 80G have been applied to centrifugally cast steel pipes. The results show: the exterior part of the steel pipes, ie, the part that contacts with the metallic mold, reveals equiaxed crystal structure; the central part shows larger columnar crystals grow perpedicularly from the mold wall; and the Widmanstatten ferrite structure is obseved on the inner part of the pipe. The faster the rotational speed, the finer the crystal structure, and the better the mechanical properties. Owing to the decarburized Widmanstatten ferrite and shrinkage defect, the mechanical properties of the inner part are inferior to those of the exterior part.