SPHEROIDIZATION ANNEALING METHOD FOR MANUFACURING HIGH CARBON STEEL SHEET HAVING EXCEELENT FARMABILITY AND HIGH CARBON STEEL SHEET PRODUCED BY THE SAME

摘要

The present invention relates to a spheroidizing method to manufacture a high-carbon steel sheet with excellent moldability, and the high-carbon steel sheet manufactured by the same. An embodiment of the present invention provides a spheroidizing method to manufacture a high-carbon steel sheet with excellent moldability comprising a primary thermal-treatment step of heating the high-carbon steel sheet at a temperature of 750-790C for 60-150 minutes, and a secondary thermal-treatment step of cooling the primarily thermal treated high-carbon steel sheet at a temperature of 640-710C for 400-1500 minutes; and the high-carbon steel sheet manufactured by the same. The present invention provides the spheroidizing method capable of obtaining excellent moldability to the steel sheet by effectively spheroidizing and refining a carbide, and remarkably reducing a time required for austenitizing by easily melting the carbide when austenitizing after machining the steel sheet.