Nippon Steel Sumitomo Metal Corporation

Toyoda Iron Works Co., Ltd.

Tomokichi Tokuda

Toshiya Suzuki

Masahiro Nakata

Masanobu Ichikawa

Nobuyuki Ichimaru

A press-formed product includes a body having a transverse cross section including a bottom portion and a shoulder portion contiguous to the bottom portion through an R end. In the transverse cross section, a first region from the R end to a position a distance away in a bottom portion extending direction, and a second region which is part of the bottom portion and is contiguous to the first region have a work-hardening distribution introduced by press-forming. The work-hardening distribution has an average hardness Hv1 of an area of the first region from a steel sheet surface to a depth obtained by multiplying a steel sheet thickness by 0.2 and an average hardness Hv2 of an area of the second region from the steel sheet surface to a position obtained by multiplying the steel sheet thickness by 0.2 to satisfy a relationship of Hv1&#x3e;1.05&#xd7;Hv2.

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Tokyo, Japan

Tomokichi Tokuda