Nippon Steel Corporation

Aoyama Seisakusho Co., Ltd.

Kazutaka Aoyama

Yutaka Neishi

Naoki Matsui

Hideo Kanisawa

Makoto Kosaka

Keisuke Chiba

Tetsushi Chida

Kazuoki Shibuya

Ryoko Inagaki

A bolt is provided that has high strength and excellent hydrogen embrittlement resistance characteristics. A bolt according to an embodiment of the present invention consists of, in mass %, C: 0.32 to 0.39%, Si: 0.15% or less, Mn: 0.40 to 0.65%, P: 0.020% or less, S: 0.020% or less, Cr: 0.85 to 1.25%, Al: 0.005 to 0.060%, Ti: 0.010 to 0.050%, B: 0.0010 to 0.0030%, N: 0.0015 to 0.0080%, O: 0.0015% or less, Mo: 0 to 0.05%, V: 0 to 0.05%, Cu: 0 to 0.50%, Ni: 0 to 0.30%, and Nb: 0 to 0.05%, with the balance being Fe and impurities. The bolt satisfies Formula (1) and Formula (2), and has a tensile strength of 1000 to 1300 MPa and satisfies Formula (3).4.9&#x2264;10C+Si+2Mn+Cr+4Mo+5V&#x2264;6.1&#x2003;&#x2003;(1)Mn/Cr&#x2264;0.55&#x2003;&#x2003;(2)[dissolved Cr]/Cr&#x2265;0.70&#x2003;&#x2003;(3)

Bolt

Growing community of inventors

Aichi, Japan

Kazutaka Aoyama