Kuraray Co., Ltd.

Kawasaki Steel Corporation

Jfe Steel Corporation

Akio Ohmori

Keniti Amano

Fumimaru Kawabata

Syuji Kawai

Masao Yuga

Kazukuni Hase

Yuki Toji

Tatsumi Kimura

Katsuyuki Ichimiya

Koichi Takakura

Shinichi Miura

Tetsuya Hara

Tomoyuki Sano

Ryokei Endo

Minoru Ueda

Koichi Nakashima

Takehiko Okamoto

Akitsugu Akiyama

Kazuhiko Shiotani

Kimihiro Nishimura

Kazuhisa Yamauchi

Akinori Sueoka

Yasuyoshi Yamane

Ryo Arao

Masashi Ando

Kohzo Yamamoto

Provided is a steel material for high heat input welding having excellent welding heat affected zone low-temperature toughness at &#x2212;55&#xb0; C. in the case that the steel material is welded by high heat input welding with a heat input of more than 80 kJ/cm. The steel material may be used in low-temperature storage tanks, for example. The steel material for high heat input welding includes, in mass %, C: 0.04 to 0.09%, Si: 0.15 to 0.25%, Mn: 1.40 to 2.00%, P: 0.015% or less, S: 0.0005 to 0.0040%, Al: 0.030 to 0.080%, Ti: 0.005 to 0.025%, B: 0.0003 to 0.0020%, Ca: 0.0005 to 0.0030%, N: 0.0030 to 0.0060%, O: 0.0040% or less, Nb: 0.005% or less, and Mo: 0.005% or less, the balance being Fe and incidental impurities.

Steel material for high heat input welding

An abrasion resistant steel plate having excellent low-temperature toughness and excellent cracking resistance in a portion which has been heated to a temperature range in which low-temperature temper embrittlement occurs and a method for manufacturing the steel plate. The steel plate includes a microstructure at positions located at &#xbc; of the thickness and at &#xbe; of the thickness including a martensite single phase microstructure having an average prior austenaite grain diameter in the range of 20 &#x3bc;m to 60 &#x3bc;m, or a mixed microstructure of martensite and bainite having a proportion of martensite-austenite constituent of less than 5% in terms of area ratio with respect to the whole microstructure.

Abrasion-resistant steel plate and method for manufacturing the same

A conductive polyvinyl alcohol fiber having good mechanical properties and heat resistance contains a polyvinyl alcohol polymer and copper sulfide nano-particles having a mean particle size of at most 50 nm which are finely dispersed in the polymer. The content of the nano-particles in the fiber is at least 0.5% by mass/polyvinyl acohol polymer, and the degree of polymer orientation is at least 60%.

Conductive polyvinyl alcohol fiber

Steel is obtained which comprises by wt %, C: 0.001-0.025%, Si: not more than 0.60%, Mn: 0.10-3.00%, P: 0.005-0.030%, S: not more than 0.01%, Al: not more than 0.10%, Cu: 0.1-1.5%, Ni: 0.1-6.0%, B: 0.0001-0.0050%, and the balance being Fe and inevitable impurities; since the steel contains C and P in small contents, stable amorphous rusts are formed on the surface thereof at an early stage; and steel simultaneously realizes excellent weather resistance, material weldability and toughness particularly in an environment such as a seashore district and the like where salt is present in a large amount.

Weatherable steel material

N&mdash;V(nitrogen-vanadium) containing continuous casting slab with no surface cracks suitable for the manufacture of non-tempered high tensile steel materials has a tensile strength of 490 MPa or more and excellent toughness. A method of manufacturing non-tempered high tensile steel materials uses the casting slab as the raw material. Compatibility between the desired properties of the materials utilizing VN and inhibition of the surface cracks of test pieces, can be attained by controlling the steel composition and the relationship between each of components of the steel thereby controlling precipitation of VN and MnS. A continuous casting slab with no surface cracks contains C, Si, Mn, P, S, Al, V, N, Ti, B, Ca and REM each within a specified range, and satisfies an equation for the relationship between V and N and a relationship between Mn and S.

Continuous casting slab suitable for the production of non-tempered high tensile steel material

A high tensile strength steel product for high heat input welding having excellent toughness in the heat-affected zone and having a tensile strength of at least 490 MPa contains, in terms of percent by weight, from about 0.05% to about 0.18% of C, 0.6% or less of Si, from about 0.80% to about 1.80% of Mn, 0.005% or less of Al, 0.030% or less of P, 0.004% or less of S, 0.005% or less of Nb, from about 0.04% to about 0.15% of V, from about 0.0050% to about 0.00150% of N, and from about 0.010% to about 0.050% of Ti, the ratio of the Ti content to the Al content, Ti/Al, satisfying 5.0 or more, and further contains at least one of from about 0.0010% to about 0.0100% of Ca and from about 0.0010% to about 0.0100% of REM, and the balance being Fe and incidental impurities. In the steel product, oxide inclusions containing, in terms of percent by weight, 20% to about 95% of a titanium oxide, 70% or less of Al O , 5% to about 50% in total of at least one of calcium oxide and a REM oxide, and 15% or less of MnO are dispersed.

High tensile strength steel product for high heat input welding, having excellent toughness in heat-affected zone

A high-strength heavy-wall H-shaped steel is excellent in Z-direction toughness at the flange thickness center. The heavy-wall H-shaped steel is comprised of by weight from about 0.05 to 0.18% C, up to about 0.60% Si, from about 1.00% to about 1.80% Mn, up to about 0.020% P, under 0.004% S, from 0.016% to 0.050% Al, from 0.04% to 0. 15% V, and from 0.0070% to 0.0200% N, and one or more of from about 0.02% to about 0.60% Cu, from about 0.02% to about 0.60% Ni, from about 0.02% to about 0.50% Cr, and from about 0.01% to about 0.20% Mo; and the balance being Fe and incidental impurities. Also, (V.times.N)/S.gtoreq.0.150; the Ti content is within a range satisfying 0.002.ltoreq.Ti.ltoreq.1.38.times.N-8.59.times.10.sup.-4 ; Ceq (=C+Si/24+Mn/6+Ni/40+Cr/5+Mo/4+V/14) is within a range of from about 0.36 wt % to about 0.45 wt %, and the yield strength is at least 325 MPa.

Heavy-wall H-shaped steel having high toughness and yield strength and

A polyvinyl alcohol (PVA) microporous membrane is disclosed which is prepared by a process which comprises forming a PVA membrane containing fine silica particles therein and substantially extracting said silica particles from said membrane, thereby forming a plurality of micropores therein with an average diameter of 0.01 to 50 microns and a porosity of at least 60%.

Polyvinyl alcohol semi-permeable membrane and method for producing same

Shaped articles comprised of PVA and PVC having improved flame-retardancy and resistance to discoloration resulting from heat treatment are provided by the incorporation therein of calcined stannic acid, characterized by a specific crystal size.

Flame-retardant fiber

A polyvinyl alcohol semi-permeable membrane is prepared which has micropores with an average diameter of 0.02 to 2 microns as defined by the interpore partition walls having thicknesses in the range of 50 to 5000 A and which is characterized by substantial cross-sectional uniformity. The membrane is prepared by extruding a PVA composition containing PAG with a molecular weight of 400 to 4,000 and a carbon-to-oxygen ratio of not more than 3 in a proportion of 2 to 200 parts by weight per 100 parts of PVA into a coagulation bath. In another embodiment of the invention, the membrane is formed from a PVA composition wherein the PAG has a molecular weight of 600 to 3,000 and a C/O ratio of not more than 3, the proportion of the PAG being 15 to 150 parts by weight per 100 parts of PVA and wherein the composition satisfies the relation: 0.65 .ltoreq. CBR (critical blending ratio) .ltoreq. 1.0. The membrane is useful in ultrafiltration, dialytic and osmotic separation applications.

PVA membrane and method for preparing the same

A dialysis membrane comprising a plurality of polyvinyl alcohol hollow fibers of substantially homogeneous structure having a degree of orientation (.pi.) in the range of 60% .ltoreq. .pi. .ltoreq. 98% and a degree of swelling (.zeta.) in the range of 1.05 .ltoreq. .pi. .ltoreq. 1.80 times.

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Kurashiki, Japan

Akio Ohmori