Hitachi Metals, Ltd.

Fujico Co., Ltd.

Ckd Corporation

Kyushu Institute of Technology

Hideaki Nagayoshi

Fumio Obata

Akio Sonoda

Kenji Kimura

Hiroshi Yoshinaga

Kouhei Imanishi

Shuzi Hayase

Kiyoshi Suehara

Hisashi Yasuda

Toshiki Yoshida

Toshiaki Tanaka

Hyo-Gyoung Kang

Hiroaki Furuta

Yasuhiro Uzu

Daishiro Nomura

Ryuzaburo Ishizaka

Hiroyuki Miyazaki

Takatoshi Nomura

Seishin Ueda

Tingli Ma

Eiji Nakano

[PROBLEM] The invention provides a roll for hot rolling process having various types of more excellent durability performances than conventional rolls, and provides also a method for manufacturing the same. [SOLUTION] A cladding layeris formed on an outer circumference portion of a roll for hot rolling process, where the cladding layercomprises: 0.5 to 0.7% by mass of C, 2.8 to 4.0% by mass of Si, 0.9 to 1.1% by mass of Cu, 1.4 to 1.6% by mass of Mn, 2.7 to 3.3% by mass of Ni, 13.5 to 14.5% by mass of Cr, 0.8 to 1.1% by mass of Mo, 0.9 to 1.1% by mass of Co, and 0.2 to 0.4% by mass of Nb, with a balance being Fe and inevitable impurities, and has a thickness of 5 mm or more.

Roll for hot rolling process and method for manufacturing same

A perovskite photoelectric conversion element includes a light transmitting substrateon a front surface of which light is made incident, an oxide porous layerformed on a rear surface of the light transmitting substrateand with metal oxide particlesconnected in a network, a metal porous layerformed on a rear surface of the oxide porous layerand with metal particlesconnected in a network, a porous insulating layerformed on a rear surface of the metal porous layera first electrode layerformed on and across an entirety of a rear surface of the porous insulating layera second electrode layerconnected to the metal porous layerand formed at a portion different from the first electrode layerin a state of being insulated from the first electrode layerand perovskite

Back contact type perovskite photoelectric conversion element

A method for manufacturing a mill roll including a preheating process for joining end portionstoof a roll barrel memberand/or shaft materials, and a friction pressure welding process strongly pressing and joining the shaft materialsto a core materialafter frictionally heating the joining end portionstoby rotating the shaft materialswhile pressing to the core material, and a manufacturing apparatus including first and second holding meansfor the roll barrel memberand the shaft materials, a rotating means rotating the shaft materials, a pressing meanspressing the core materialand the shaft materialsin an axial direction, and a preheating meanspreheating the joining end portionstoof the roll barrel memberand the shaft materials

Method for manufacturing mill roll, mill roll and manufacturing apparatus of mill roll

A method of producing a spheroidal graphite cast iron article containing at least one pearlite stabilizing element selected from the group consisting of Mn, Cu, Sn, Sb and Pb and having a double layer structure which comprises a surface layer portion and an inner portion. The surface layer portion has a matrix 60% or more of which is ferrite phase and a thickness of at least 0.5 mm. The inner portion has a matrix substantially comprising pearlite phase. The method comprises: (1) heat-treating a starting spheroidal graphite cast iron at a temperature which transforms a whole part of a matrix of the starting spheroidal graphite cast iron substantially to austenite phase; (2) slowly cooling the austenitized spheroidal graphite cast iron at a cooling rate (5.degree. to 20.degree. C./min) which allows in a subsequent step the surface layer portion to be ferritized before the inner portion starts to be pearlitized; (3) holding the cooled spheroidal graphite cast iron at a temperature (710.degree. to 770.degree. C.) which allows the surface layer portion to be first ferritized and subsequently allows the inner portion to be pearlitized while preventing the ferrite phase of the surface layer portion from being transformed to another; and (4) cooling the spheroidal graphite cast iron thus transformed immediately after completion of the pearlitization of the inner portion.

Method of producing spheroidal graphite cast iron article

Spheroidal graphite cast iron for crank shafts having a tensile strength of 75 kgf/mm.sup.2 or more, and having excellent conformability and machinability, which cast iron consisting, by area ratio, of graphite of 5 to 15%, ferrite of not more than 10%, and the balance pearlite matrix, said cast iron having a Brinell hardness (HB) of 241 to 277.

Spheroidal graphite cast iron for crank shafts and a crank shaft

The spheroidal graphite cast iron member having a surface layer portion mostly composed of a ferrite phase and having a thickness of at least 1 mm, and an inner portion composed of a pearlite phase and a ferrite phase, the surface layer portion having a ferritization ratio of 70% or more which is larger than that of the inner portion by at least about 15% is produced by (a) pouring a spheroidal graphite cast melt into a casting mold; (b) removing the casting mold by shake-out after the completion of solidification of the melt, while substantially the entire portion of the resulting cast iron product is still at a temperature of its A.sub.1 transformation point or higher; (c) when the temperature difference between the surface layer portion and the inner portion has become 40.degree.-60.degree. C., introducing the cast iron product into a uniform-temperature furnace kept at 750.degree.-900.degree. C., where the cast iron product is held for such a time period as to produce the surface layer portion having a ferritization ratio of 70% or more which is larger than that of the inner portion by at least about 15%; and (d) transferring the cast iron product into a cooling furnace to cool the cast iron product at a cooling speed of 15.degree.-100.degree. C./min.

Spheroidal graphite cast iron member having improved mechanical strength

A spheroidal graphite cast iron article having a thin portion and a thick portion, the number of spheroidal graphite particles having a diameter of 2 .mu.m or more being 600 /mm.sup.2 or more and less than 2000 /mm.sup.2 in the thin portion and 130 /mm.sup.2 or more and less than 600 /mm.sup.2 in the thick portion, and spheroidization percentage being 70% or more in the thick portion, is produced by a method comprising the steps of: (a) preparing an iron-base alloy melt having a composition consisting essentially by weight of 3.0-4.0% of C, 0.8-1.7% of Si, 1.0% or less of Mn, 0.2% or less of P, 0.01-0.2% of S, the balance being substantially Fe and inevitable impurities; (b) desulfurizing the iron-base alloy melt to control the sulfur content of the melt to less that 0.01% by weight; (c) adding a sulfur-containing material to the melt in such an amount that the sulfur content of the melt becomes 0.011-0.03% by weight; and (d) adding an Mg-containing material and a lanthanide element to the melt to conduct a spheroidizing treatment.

A heat treatment apparatus for thin spheroidal graphite cast iron products comprising a cast iron product remover for removing a thin spheroidal graphite cast iron product from a casting mold; a continuous furnace having an inlet positioned near the cast iron product remover, the continuous furnace comprising a uniform temperature zone kept at a temperature equal to or higher than an A.sub.3 transformation point of the thin spheroidal graphite cast iron product and a cooling zone downstream of the uniform temperature zone; a first conveying means for the thin cast iron product disposed between the cast iron product remover and the inlet of the continuous furnace; and a second conveying means for the thin cast iron product moving through the continuous furnace, the thin cast iron product being conveyed to the second conveying means by means of the first conveying means immediately after removed from the casting mold and introduced into the continuous furnace by means of the second conveying means.

Heat treatment apparatus for thin spheroidal graphite cast iron products

A thin high-strength article of spheroidal graphite cast iron having graphite particles dispersed in a ferrite matrix containing 10% or less of pearlite, characterized in that there are substantially no fine gaps between the graphite particles and the ferrite matrix. It is produced by pouring a melt having a spheroidal graphite cast iron composition into a casting mold; removing the casting mold by shake-out, while substantially the entire portion of the resulting cast iron product is still at a temperature of its A.sub.3 transformation point or higher; immediately introducing the cast iron product into a uniform temperature zone of a continuous furnace kept at a temperature of the A.sub.3 transformation point or higher, where the cast iron product is held for 30 minutes or less to decompose cementite contained in the matrix; and transferring the cast iron product into a cooling zone of the continuous furnace to cool the cast iron product at such a cooling speed as to achieve the ferritization of the matrix.

Growing community of inventors

Kitakyushu, Japan

Hideaki Nagayoshi