METHOD OF PRODUCING STEEL PRODUCT FOR CARBURIZATION HAVING EXCELLENT GRAIN SIZE PROPERTY AND MACHINABILITY

摘要

PROBLEM TO BE SOLVED: To provide a method of producing a steel product which has excellent machinability in addition to excellent grain size properties without performing additional heat treatment stages such as annealing by stipulating chemical components in the steel and thermal history in the production of the steel.;SOLUTION: In the method of producing a steel product for carburization, steel having a composition containing, by mass, 0.10 to 0.45% C, 0.03 to 1.0% Si, 0.2 to 2.0% Mn, 0.05 to 0.2% Ti, 0.005 to 0.05% Al and ≤0.01% N, and the balance Fe with inevitable impurities is once heated to ≥1,250°C, is cooled to ordinary temperature, and is thereafter reheated to a temperature range of 800 to 1,100°C in thermal history of a series of working stages including a rolling stage from an ingot or a bloom into a slab, the subsequent rolling stage into a bar steel wire rod and a forging stage into a product.;COPYRIGHT: (C)2004,JPO