Abstract:
본 발명은 냉간 압조성이 우수하여, 볼트 제조시 구상화 열처리 및 퀀칭-템퍼링 처리가 필요치 않은 고강도 고망간 강선재와 이를 제조하는 방법 및 상기 강선재를 이용한 볼트의 제조방법을 제공한다. 본 발명은 망간(Mn) 12~25중량%를 포함하는 강을 1100~1250℃로 가열하는 단계; 상기 가열된 강을 700~1100℃에서 열간 압연하는 단계; 및 상기 열간 압연된 강을 200℃이하의 온도로 냉각하고, 냉간 공형 압연 또는 인발하여 강선재를 제조하는 단계를 포함하는 냉간 압조성이 우수한 고강도 고망간 강선재의 제조방법과 이를 통해 제조된 강선재 및 이를 이용한 볼트의 제조방법을 제공한다.
Abstract:
PURPOSE: A method of enhancing resistance to the hydrogen delayed destruction of TWIP steel is provided to enhance durability and to ensure stability by enhancing resistance to the hydrogen delayed destruction of super-strength TWIP steel. CONSTITUTION: A method of enhancing resistance to the hydrogen delayed destruction of TWIP steel is as follows. A martensitic phase change layer is removed from the surface of a steel member. The phase change layer is removed by surface milling. The surface milling is done by grinding or cutting.
Abstract:
PURPOSE: A high-strength and high-Mn steel wire rod with excellent cold forging property, a manufacturing method thereof, and a bolt manufacturing method using the same are provided to reduce the weight of parts by excluding a heat treatment process and utilizing the steel wire rod for the parts. CONSTITUTION: A method for manufacturing a high-strength and high-Mn steel wire rod with excellent cold forging property comprises the steps of: heating steel including Mn of 12-25wt.% to 1100-1250°C, hot rolling the heated steel at 700-1100°C, cooling the hot rolled steel below 200°C, and cold caliber-rolling or drawing the steel into a steel wire rod. [Reference numerals] (AA) Temperature(°C); (BB) 1200°C heating; (CC) 1100°C hot rolling; (DD) Cold caliber-rolling or drawing; (EE) Time(t)