Jfe Steel Corporation

Yota Kuronuma

Tomoyuki Yokota

Hirofumi Ohtsubo

Kazukuni Hase

Yoshihiro Yazawa

Junji Shimamura

Katsuyuki Ichimiya

Kimihiro Nishimura

Shigeki Kitsuya

Shinji Mitao

Ryosuke Sakai

Hitoshi Sueyoshi

Keiichiro Kishi

Shunichi Tachibana

Toshiyuki Hoshino

Disclosed is a duplex stainless clad steel plate in which a duplex stainless steel plate as a cladding metal is bonded or joined to one or both surfaces of a base steel plate, in which the base steel plate comprises a predetermined chemical composition such that Nb/N is 3.0 or more and Ceq is 0.35 to 0.45, and the duplex stainless steel plate comprises: a predetermined chemical composition such that PI is 34.0 to 43.0; and a microstructure containing a ferrite phase in an area fraction of 35% to 65%, and in the microstructure, an amount of precipitated Cr is 2.00% or less and an amount of precipitated Mo is 0.50% or less.

Duplex stainless clad steel plate and method of producing same

Disclosed is a duplex stainless clad steel plate in which a duplex stainless steel plate as a cladding metal is bonded or joined to one or both surfaces of a base steel plate, in which the base steel plate comprises a predetermined chemical composition such that Nb/N is 3.0 or more and Ceq is 0.35 to 0.45, and the duplex stainless steel plate comprises: a predetermined chemical composition such that PI is 33.0 to 38.0; and a microstructure containing a ferrite phase in an area fraction of 35% to 65%, and in the microstructure, an amount of precipitated Cr is 1.00% or less and an amount of precipitated Mo is 0.50% or less.

Disclosed is a clad steel plate with further improved low temperature toughness along with excellent HIC resistance while ensuring a tensile strength of 535 MPa or more. A clad steel plate includes: a base steel; and a clad metal made of a corrosion resistant alloy bonded to one surface of the base steel, in which the base steel has: a chemical composition with appropriately controlled values of ACR and P; and a steel microstructure in which bainite is present in an area fraction of 94% or more at a &#xbd; thickness position in a thickness direction of the base steel, and with an average crystal grain size of 25 &#x3bc;m or less, and shear strength at a bonded interface between the base steel and the cladding metal is 300 MPa or more.

Clad steel plate and method of producing the same

A thick steel plate is provided by heating a continuously-cast slab, hot forging the continuously-cast slab using opposing dies having respective short sides differing such that when a short side length of a die having a shorter one of the short sides is taken to be 1, a short side length of a die having a longer one of the short sides is 1.1 to 3.0, allowing cooling to obtain a steel raw material, reheating the steel raw material, performing hot rolling of the steel raw material including at least two passes carried out, allowing cooling to obtain a thick steel plate, reheating the thick steel plate to at least the Actemperature and no higher than 1050&#xb0; C., rapidly cooling the thick steel plate to 350&#xb0; C. or lower, and tempering the thick steel plate at at least 550&#xb0; C. and no higher than 700&#xb0; C.

High toughness and high tensile strength thick steel plate with excellent material homogeneity and production method for same

A cladding material for stainless steel clad steel plate, includes, by mass %, 0.03% or less carbon, 1.5% or less silicon, 2.0% or less manganese, 0.04% or less phosphorus, 0.03% or less sulfur, 22.0% to 25.0% nickel, 21.0% to 25.0% chromium, 2.0% to 5.0% molybdenum, 0.15% to 0.25% nitrogen, and the balance being iron and incidental impurities, wherein critical pitting temperature (CPT) after normalization as determined in accordance with ASTM G48-03 Method E is 45&#xb0; C. or higher, and corrosion loss at a welded zone as determined by a corrosion test in accordance with NORSOK Standard M-601 is 1.0 g/mor less.

Stainless steel clad steel plate including cladding material for stainless steel clad steel plate and method of manufacturing the same

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Tokyo, Japan

Yota Kuronuma