Abstract: With the methods of in-situtemperature measure and design of orthogonal test and computer solidification numerical simulation, the feeding character when a riser on hot spot and away from hot spot are studied. The re suits show that it is feasible to apply technical principle of dynamic directoinal solidification in steel casting. The dynamic directional solidification means that the riser may be away from hot spot but not far, and that junction-effect of neighbourhood in riser pad and surge flow of feeding metal in riser are made use of. As compared with traditional geometry directional solidification, the principle of dynamic directional solidification can help to avoid contraction defects, to promote internal quality, and to raise riser efficiency.

Key words: Dynamic directional solidification, Riser away from hot spot, Steel casting