Jfe Steel Corporation

Satoshi Igi

Tatsumi Kimura

Keisuke Ando

Tomoyuki Yokota

Shigeki Kitsuya

Takahiro Sakimoto

Koichi Nakashima

Daichi Izumi

Hisakazu Tajika

Tomohiro Ono

Ryo Arao

Teruki Sadasue

Keiji Ueda

The rail having a chemical composition containing C: 0.70-0.85 mass %, Si: 0.50-1.60 mass %, Mn: 0.20-1.00 mass %, P: 0.035 mass % or less, S: 0.012 mass % or less, Cr: 0.40-1.30 mass %, the chemical composition satisfying the formula (1)0.30&#x2264;[% Si]/10+[% Mn]/6+[% Cr]/3&#x2264;0.55&#x2003;&#x2003;(1)

Rail and method for manufacturing same

The rail having a chemical composition containing C: 0.70-1.00 mass %, Si: 0.50-1.60 mass %, Mn: 0.20-1.00 mass %, P: &#x2264;0.035 mass %, S: &#x2264;0.012 mass %, Cr: 0.40-1.30 mass %, where Ceq defined by the formula (1) is 1.04-1.25,Ceq=[% C]+([% Si]/11)+([% Mn]/7)+([% Cr]/5.8)&#x2003;&#x2003;(1)

In a steel pipe having a waveform shape formed on an outer diameter thereof by a pipe expansion process, a value a/w is 0.038% or less, where a and w denote an amplitude and a wavelength of the waveform shape, respectively. A method of manufacturing a steel pipe having a waveform shape formed on an outer diameter thereof by a pipe expansion process includes a step of forming the waveform shape such that a value a/w is 0.038% or less, where a and w denote an amplitude and a wavelength of the waveform shape, respectively.

Steel pipe, steel pipe structure, method of manufacturing steel pipe, and method of designing steel pipe

A circumferential welded joint of a line pipe is formed by butting against each other end portions of steel pipes having a yield strength according to 5L Specification of API Standards not smaller than 555 N/mmand welding the butted portions in a circumferential direction. A joint strength ratio &#x3c3;=(TS-w/TS-b)&#xb7;(YS-w/YS-b) represented by a product of a ratio between a tensile strength TS-w of a weld metal and a tensile strength TS-b of a base material and a ratio between a yield strength YS-w of the weld metal and a yield strength YS-b of the base material, and a critical equivalent plastic strain &#x3b5;[%] for ductile crack generation in a base material heat affected zone satisfy Equation (1), and the yield strengths YS-w, YS-b of the weld metal and base material satisfy Equation (2).&#x3c3;&#x3e;4.85&#x3b5;&#x2003;&#x2003;(1)YS-/YS-&#x2267;1.0&#x2003;&#x2003;(2)

Circumferential welded joint of line pipe, method of forming circumferential welded joint of line pipe, and line pipe

A UOE steel pipe used to form a structure by performing butt circumferential welding and having an outside diameter shape in a waveform in a longitudinal direction is shaped to have no local minimum of the outside diameter shape in the waveform within a predetermined length from both longitudinal end portions.

Growing community of inventors

Tokyo, Japan

Satoshi Igi