REINFORCING BEAM FOR VEHICULAR DOOR, AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a reinforcing beam for a vehicular door and a manufacturing method for the reinforcing beam formed in crosssectional shape which sufficiently increases second moment of area, having sufficient strength against load such as impact load and miniaturizable by shortening a width dimension. SOLUTION: A steel plate with tensile strength T in a range of 294.1995 N/mm<2> <=T<=784.532 N/mm<2> is used as the material of this reinforcing beam 20, and the steel plate is subjected to press forming and quenching treatment to form the reinforcing beam 20 comprising a beam body 21 and two brackets 22. The reinforcing beam 20 smaller in the tensile strength than that of material of a conventional reinforcing beam manufactured by press-forming a steel plate and larger in the second moment of area can be acquired, and the strength of the reinforcing beam 20 can be increased by the quenching treatment.