| 摘要 |
PURPOSE: A steel product and a manufacturing method thereof are provided to form a pure ausferrite structure without graphite nodule by controlling alloying constituents and process conditions. CONSTITUTION: A steel product manufacturing method comprises the following steps. A wire is formed by hot-rolling a bloom which is composed of, in wt%: C 0.8-1.0; Si 2.0-3.0; Mn 0.3-0.4; P 0.05 or less; S 0.03 or less; the remainder Fe; and other inevitable impurities(S110). The wire is processed to form a steel product(S120). The steel product is spheroidized and heat-treated(S130). The spheroidized and heat-treated steel product is heat-treated with austenizing(S140). The spheroidized and heat-treated steel product is cooled to 240-280>=, and then austempered for 50-150 minute(S150). [Reference numerals] (AA) Start; (BB) End; (S110) Hot-rolling; (S120) Processing; (S130) Spheroidizing and heat-treating; (S140) Austenizing; (S150) Austempering; |
