After it administers the cast piece production manner of the steel for carburization, whose heat treatment deformation variation

摘要

PROBLEM TO BE SOLVED: To provide a continuous casting method for a constant strain carburization steel slab for a machining component in which variation in a dimensional change by heat treatment of the carburization steel for hollow shaft components for an automobile or the like is suppressed, dimensional accuracy is excellent and shape correcting by way of cutting or polishing after the heat treatment can be omitted, and to provide a constant strain carburization steel slab.;SOLUTION: In the slab manufacturing method for continuous casting of the carburization steel containing the carbon content of less than 0.5 mass % to be used for the hollow shaft components which are subjected to plastic work accompanied by plastic fluidity to the axial direction, then an axis insertion part is punched from the center part into a predetermined shape, the magnetic flux density of the M-EMS strength during the continuous casting is controlled to 30 to 100 μT to set the average molten steel flow rate in a mold to 2 cm/s to 15 cm/s, and the area ratio of the slab center segregation zone to be used for the hollow shaft components is lessened to continuously cast the constant strain carburization steel slab.;COPYRIGHT: (C)2004,JPO