| 摘要 |
PURPOSE: A hot-formed door beam with a tensile strength of 1400MPa and a manufacturing method thereof are provided to maximize safety of passengers against a vehicle collision. CONSTITUTION: A method for manufacturing a hot-formed door beam with a tensile strength of 1400MPa comprises the steps of: forming a steel pipe out of a steel material which comprises C of 0.26-0.28weight%, Mn of 2.0weight% or less, P of 0.003weight% or less, S of 0.003weight% or less, Cr of 0.29-0.31weight%, Mo of 0.34-0.36weight%, B of 0.004weight% or less, and Fe and inevitable impurities of the remaining amount(ST100), cutting the steel pipe to the length of a door beam(ST200), heating the cut steel pipe with an induction heating method(ST300), and hot-forming and quenching the heated steel pipe into a door beam(ST400). [Reference numerals] (ST100) Steel pipe preparation step; (ST200) Cutting step; (ST300) Heating step; (ST400) Hot-forming and quenching step |
