Nippon Steel Nisshin Co., Ltd.

Nisshin Steel Co., Ltd.

Toru Ienari

Hiroshi Asada

Yasuhiro Sakurada

A laser-welded shape section steel includes a web member and a flange member each made of a steel plate, the steel plate having an equivalent carbon content Cof not less than 0.075 and not more than 0.15, the equivalent carbon content Cbeing represented by the following formula: C=C+(Si/50)+(Mn/25)+(P/2)+(Cr/25)+Ti, where a welded part, which is a joint part in which the web member and the flange member are joined, has a hardness of not less than 1.2 times and not more than 4 times as hard as that of the steel plate, and the welded part a protrusion length of not greater than 1 mm.

Growing community of inventors

Tokyo, Japan

Toru Ienari