The Japan Steel Works, Ltd.

Tokyo Denki University

Japan Steel Works M&e, Inc.

Yoru Wada

Yasuhiko Tanaka

Ryoji Ishigaki

Hirokazu Tsuji

Takafumi Hosoya

Kouichi Takasawa

Rinzo Kayano

Hironobu Arashima

Koichi Takasawa

Yusuke Yanagisawa

Tatsuo Hasegawa

Hirokazu Inoue

A hydrogen pressure vessel capable of preventing hydrogen-induced cracking of a cylinder is provided. In a hydrogen pressure vessel according to one embodiment, a gap part (G) in which an inner peripheral surface of a cylinder () is spaced apart from an outer peripheral surface of a lid () is provided between a female thread part () of the cylinder () into which the lid () is screwed, and a resin seal member (), and the cylinder () includes a first through hole () for discharging gas in the gap part (G) into a relief pipe () and a second through hole () for introducing gas containing oxygen into the gap part (G) formed therein.

Hydrogen pressure vessel

A gas pressure vessel capable of performing processing of removing wrinkles on an inner surface of a dome part and preventing cracking starting from a root of a thread of a neck part is provided. In a gas pressure vessel according to one embodiment, a dome part () has an opening whose diameter is 90 mm or greater, and the innermost root of the thread in a female thread part () into which a lid () is screwed is provided inside an imaginary plane (B) formed by extending an outer surface of the dome part () toward an opening.

Gas pressure vessel

A pressure vessel () is provided with: a cylinder part () that defines a pressure chamber (); a screwing part () that is disposed inside at least one of the two ends of the cylinder part; a lid () that has a pressure-receiving surface (A) facing the pressure chamber and that is disposed at a position closer to the pressure chamber than is the screwing part; and a reinforcing ring () that is fitted to the outer circumferential surface of the cylinder part. The reinforcing ring covers, along the axial direction of the cylinder part, a part on an outer circumferential surface (F) corresponding to a portion or the entirety of the engaging portion () between the cylinder part and the screwing part.

Pressure vessel

An accumulator vessel () includes a screwable portion () and a lid portion () that is positioned at an axially inner side of the screwable portion and an axially inner surface configures a pressure bearing plane. The lid portion includes a protruding portion () extending axially outward on an inner circumferential side, and the protruding portion configured to abut against an axially inner end side of the screwable portion to separate an axially inner surface of the screwable portion on an outer circumferential side thereof apart from an axially outer surface of the lid portion on an outer circumferential side thereof.

Pressure accumulation container

An object of the present invention is to provide at a low cost a low-alloy steel having a high strength and excellent high-pressure hydrogen environment embrittlement resistance characteristics under a high-pressure hydrogen environment. The invention is a high-strength low-alloy steel having high-pressure hydrogen environment embrittlement resistance characteristics, which has a composition comprising C: 0.10 to 0.20% by mass, Si: 0.10 to 0.40% by mass, Mn: 0.50 to 1.20% by mass, Ni: 0.75 to 1.75% by mass, Cr: 0.20 to 0.80% by mass, Cu: 0.10 to 0.50% by mass, Mo: 0.10 to 1.00% by mass, V: 0.01 to 0.10% by mass, B: 0.0005 to 0.005% by mass and N: 0.01% by mass or less, and further comprising one or two of Nb: 0.01 to 0.10% by mass and Ti: 0.005 to 0.050% by mass, with the balance consisting of Fe and unavoidable impurities.

High-strength low-alloy steel excellent in high-pressure hydrogen environment embrittlement resistance characteristics and method for producing the same

In a method of determining a fatigue crack lifetime of a low-alloy steel material coming in contact with high-pressure hydrogen in a high-pressure hydrogen environment, estimate a fatigue crack acceleration starting point Kof the low-alloy steel material using a crack-growth threshold stress intensity factor Kobtained through a rising load test on the low-alloy steel material in a high-pressure hydrogen environment. The high-pressure hydrogen environment of the rising load test is a high-pressure hydrogen environment which has the same pressure and atmosphere as in the high-pressure hydrogen environment in which Kis estimated and in which the test temperature tolerance between both environments is &#xb1;5&#xb0; C.

Method of determining fatigue crack lifetime in high-pressure hydrogen environment

An object of the present invention is to provide at a low cost a low-alloy steel having a high strength and excellent high-pressure hydrogen environment embrittlement resistance characteristics under a high-pressure hydrogen environment. The invention is a high-strength low-alloy steel excellent in high-pressure hydrogen environment embrittlement resistance characteristics, which is characterized in that the steel has a composition comprising C: 0.10 to 0.20%, Si: 0.10 to 0.40%, Mn: 0.50 to 1.20%, Cr: 0.20 to 0.80%, Cu: 0.10 to 0.50%, Mo: 0.10 to 1.00%, V: 0.01 to 0.10%, B: 0.0005 to 0.005% and N: 0.01% or less, by mass, with the balance consisting of Fe and unavoidable impurities.

A method of determining fatigue of a pressure-resistant component for high-pressure hydrogen made of a ferritic steel and provided in a high-pressure hydrogen gas environment is provided wherein when the material of the ferritic steel in the air has an ultimate tensile strength Su in the range of 958-1,144 MPa and the hydrogen gas environment has a pressure in a range to 45 MPa, then a fatigue strength in a gaseous hydrogen S(MPa) for the pressure-resistant component provided in the high-pressure hydrogen gas environment is obtained by using equation (1): S(MPa)=2,577&#x2212;1.8925&#xd7;Su (MPa). The influence of a high-pressure hydrogen gas environment on the pressure-resistant component for high-pressure hydrogen is determined based on the fatigue strength obtained by using the equation (1).

Method of determining fatigue of pressure-resistant component for high-pressure hydrogen

Using information about the position, orientation, and shape of a crack appeared in a judged material and information about the structure of the judged material as parameters, the stress intensity factor Kof the crack is found. Based on the stress intensity factor K, hydrogen embrittlement cracking of the judged material is judged. The crack growth rate and possibility of brittle fracture can be judged by comparing the stress intensity factor Kwith the critical stress intensity factor Kfor crack initiation or the critical stress intensity factor Kfor brittle fracture about the temper embrittled steel which absorbs approximately 2.0 ppm hydrogen.

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Muroran, Japan

Yoru Wada