| 摘要 |
A manufacturing method of a high strength reinforcement for an automobile using hot stamping is provided to manufacture automotive parts which require high strength and dimensional accuracy and are formed in a complicated shape in an accurate and easy manner. In a manufacturing method of a high strength reinforcement for automobile using hot stamping, comprising a blanking process of blanking a reinforcement workpiece for automobile of which average composition and crystal structure are generally the same as those of a ferritic cold rolled or hot rolled workpiece as an ordinary reinforcement for automobile with a tensile strength of 60 kg/mm^2 grade or more, the average composition comprising 2137.0 ppm of C, 2456.0 ppm of Si, 11874.0 ppm of Mn, 182.3 ppm of P, 9.2 ppm of S, and 23.8 ppm of B; a heating process of the blanked workpiece; a transfer process of the heated workpiece; pressing and quenching processes of the transferred workpiece in a mold; and a post-treatment process of the quenched workpiece, the manufacturing method is characterized in that the workpiece is heated at an austenite stabilization temperature to 950 deg.C for 4 to 6 minutes, a quenching rate of the heated workpiece in the mold is controlled to 30 to 260 deg.C/sec to obtain a martensitic metal structure, and the workpiece is held in the mold for 20 to 28 seconds in the quenching process to prevent the workpiece from being deformed. |
