Nippon Steel Corporation

Noriyuki Suzuki

Kazuhisa Kusumi

Manabu Takahashi

Toshiyuki Kanda

Nobuhiro Fujita

Shinya Nakajima

Kunio Hayashi

Masahiro Oogami

Yuzo Takahashi

Hironori Sato

Jun Maki

Masayuki Abe

High-strength parts and a method for producing them can be provided, where such parts exhibit hydrogen embrittlement resistance and strength after high-temperature forming. For example, the atmosphere in a heating furnace can contain less than about 10% hydrogen and/or have a dew point of about 30&#xb0; C. or less. The amount of hydrogen penetrating a steel sheet during heating can thereby be reduced. After forming, quench hardening in a die assembly and post-working can be performed. Post-working can include shearing followed by re-shearing or compression forming; punching with a cutting blade having a continuously reduced base width; punching with a tool having a curved blade and a protrusion at the tip of the cutting blade, where the curved blade may include a shoulder portion of given radius and/or angle; fusion cutting; etc. Tensile residual stresses after punching can be reduced and resistance to hydrogen embrittlement can be improved.

High strength part and method for producing the same

Growing community of inventors

Chiba-ken, Japan

Masahiro Oogami