Nisshin Steel Co., Ltd.

Mitsubishi Jukogyo Kabushiki Kaisha

Toshiharu Kittaka

Kenichi Yanagi

Yoshio Shimozato

Tetsuyoshi Wada

Kanji Wake

Norio Tsukiji

Takuya Aiko

Heizaburo Furukawa

Yasuji Nakanishi

Mitsuo Kato

Arihiko Morita

Takefumi Nakako

Atsushi Komatsu

Kouichi Watanabe

Minoru Saito

Yusuke Hirose

Atsushi Andoh

Takao Tsujimura

Mitsuo Katoh

Nobuhiko Yamaki

Takeshi Nagatani

Kazuaki Chohata

Takeyuki Yoshida

Masahiro Nakata

Kenji Ooshima

Shigeo Matsubara

Heisaburo Furukawa

Hiroki Kanazawa

Hiroyuki Tanase

Tetsuo Itou

Hiromichi Shiroma

Tatsurou Iwasaki

Shozo Umeda

A sleevefor introduction of a pressurized fluid, which is attached to a rockbolt main body, comprises a cylindrical projecting partof a large diameter and a bearing-plate-holding partof a diameter smaller than an aperture of a bearing plate. The projecting partand the bearing-plate-holding partpreferably has the same inner diameter. When the rockbolt main bodyis embedded in a bedrock or ground, the bearing platelocates on an edge of a rockbolt-setting hole of the bedrock or ground, and the bearing-plate-holding partextends through the bearing plateinto the rockbolt-setting hole. Since the projecting partand the bearing plateare disposed on a sprayed concrete layer, a projection height of the rockbolt is remarkably decreased. Consequently, lining concreteis applied onto the sprayed concrete layer with ease, and the bedrock or ground is reinforced with high reliability.

Rockbolts made of steel pipes

A high-strength steel pipe rockbolt has an expansive rockbolt main body prepared by processing a high-strength steel sheet of 1.8-2.3 mm in thickness with a tensile strength of 490-640 N/mmand an elongation of 20% or more into a welded pipe and roll-forming the welded pipe into a shaped pipe having one or more concavities extending along an axial direction. Use of the high-strength steel sheet ensures sufficient strength of the shaped pipe regardless of a decrease in thickness. The thin welded pipe is also advantageous in resistance to cracking caused by accumulation of strains introduced during roll-forming, swaging both ends of the welded pipe and hydraulic expansion. Moreover, expansive deformation of the shaped pipe is initiated by injection of a pressurized fluid at a low pressure, so that the expansive deformation is completed in a short time period with an improved working efficiency.

Rockbolt of high strength steel pipe and method of manufacturing the same

A hot-dip Zn&mdash;Al&mdash;Mg plated steel sheet good in corrosion resistance and surface appearance that is a hot-dip Zn-base plated steel sheet obtained by forming on a surface of a steel sheet a hot-dip Zn&mdash;Al&mdash;Mg plating layer composed of Al: 4.0-10 wt. %, Mg: 1.0-4.0 wt. % and the balance of Zn and unavoidable impurities, the plating layer having a metallic structure including a primary crystal Al phase or a primary crystal Al phase and a Zn single phase in a matrix of Al/Zn/Zn Mg ternary eutectic structure. To obtain a plating layer possessing this metallic structure, the cooling rate of the plating layer adhering to a steel strip extracted from a plating bath and the plating bath temperature are appropriately controlled in a continuous hot-dip plating machine and/or appropriate amounts of Ti and B are added to the bath. Occurrence of a stripe pattern peculiar to this plated steel sheet is controlled by morphology control of a Mg-containing oxide film up to solidification of the plating layer or by adding an appropriate amount of Be to the plating bath.

Hot-dip Zn-A1-Mg plated steel sheet good in corrosion resistance and surface appearance and method of producing the same

A hot-dip Zn&mdash;Al&mdash;Mg plated steel sheet good in corrosion resistance and surface appearance that is a hot-dip Zn-base plated steel sheet obtained by forming on a surface of a steel sheet a hot-dip Zn&mdash;Al&mdash;Mg plating layer composed of Al: 4.0-10 wt. %, Mg: 1.0-4.0 wt. % and the balance of Zn and unavoidable impurities, the plating layer having a metallic structure including a primary crystal Al phase or a primary crystal Al phase and a Zn single phase in a matrix of Al/Zn/Zn,Mg ternary eutectic structure. To obtain a plating layer possessing this metallic structure, the cooling rate of the plating layer adhering to a steel strip extracted from a plating bath and the plating bath temperature are appropriately controlled in a continuous hot-dip plating machine and/or appropriate amounts of Ti and B are added to the bath. Occurrence of a stripe pattern peculiar to this plated steel sheet is controlled by morphology control of a Mg-containing oxide film up to solidification of the plating layer or by adding an appropriate amount of Be to the plating bath.

Hot-dip Zn-Al-Mg coated steel sheet excellent in corrosion resistance and surface appearance and process for the production thereof

A system for making an on-line determination of the degree of alloying in galvannealed steel sheets are provided, which includes an X-ray tube for generating X-ray, detectors for detecting the X-ray diffraction intensity of the .zeta. phase and .GAMMA. phase of Fe--Zn intermetallic compounds phases of the galvannealed steel sheet and a detector for detecting the background intensity, all of the detectors being located same plane on the surface of the galvannealed steel sheets, and further includes an arithmetic unit for receiving the outputs of the detectors to compute the X-ray diffraction intensities. Preferably, this system includes a detector for detecting the X-ray diffraction intensity of the .delta..sub.1 phase.

System for making an on-line determination of degree of alloying in

A method for estimating the press formability of galvannealed steel sheets provided, wherein: the values found by: ##EQU1## wherein I(.gamma.)=the total X-ray diffraction intensity of the .gamma. phase,

Method for estimating the press formability of galvannealed steel sheets

For vacuum deposition plating steel strip, a vacuum deposition plating apparatus is used including an inlet-side vacuum sealing device provided in front of a vacuum deposition plating chamber, with an inlet-side inactive gas replacement chamber provided between the inlet-side vacuum sealing device and an annealing furnace. An outlet-side vacuum sealing device is provided at the rear of the vacuum deposition plating chamber, with an outlet-side inactive gas replacement chamber provided between the outlet-side vacuum sealing device and the atmosphere. An inactive gas circulating/purifying device circulates an inactive gas from vacuum chambers of both the vacuum sealing devices to atmospheric pressure chambers of both the vacuum sealing devices and removes water, oil and oxygen from the inactive gas. Oxygen and hydrogen in the inactive gas are regulated to provide 60 ppm or less of oxygen and 0.2 to 2.0% of hydrogen, and also to regulate the dew point of the inactive gas to -50.degree. C. or less. Further, a pressure P.sub.1 in the annealing furnace, a pressure P.sub.2 in the inlet-side inactive gas replacement chamber, and a pressure P.sub.3 in the outlet-side inactive gas replacement chamber are maintained at atmospheric pressure or more. A value of P.sub.1 -P.sub.2 can be kept at 0 mmAq or more, and the concentration of hydrogen in the inlet-side inactive gas replacement chamber is held to 2.0.degree. or less.

Method for vacuum deposition plating steel strip

A vacuum deposition plating apparatus having an inlet-side vacuum sealing device provided in front of a vacuum deposition plating chamber, an inlet-side inactive gas replacement chamber provided between the inlet-side vacuum sealing device and an annealing furnace, an outlet-side vacuum sealing device provided in the rear of the vacuum deposition plating chamber, an outlet-side inactive gas replacement chamber provided between the outlet-side vacuum sealing device and the atmosphere, and an inactive gas circulating/purifying device for circulating an inactive gas from vacuum chambers of both the vacuum sealing devices to atmospheric pressure chambers of both the vacuum sealing devices and for removing water, oil and oxygen from the inactive gas; a pressure gauge provided on the annealing furnace; a pressure gauge, a control valve, an automatic valve, a hydrogen concentration detector and a discharge valve provided on the inlet-side inactive gas replacement chamber; a pressure gauge and an automatic valve provided on the outlet-side inactive gas replacement chamber; and an automatic valve connecting to an inactive gas tank for emergency provided on the atmospheric pressure chambers of both the vacuum sealing devices.

Method and apparatus for vacuum deposition plating

A continuous vacuum deposition apparatus for coating a metal strip in which a control means for changing the width of the metal vapor channel so that strips of various widths can be deposition-coated with transversally uniform thickness distribution is disclosed.

Continuous vacuum deposition apparatus with control panels for

A vacuum evaporation equipment for continuous vacuum evaporation of a metal onto a band or strip of product including at least one vacuum sealing station, provision of ducts that are disposed surrounding the band product and extending from the point of vapor deposition where the band product is subjected to a vacuum evaporation process an a chamber held at a reduced pressure or vacuum state to the extent that substantially no reevaporation of once deposited metal is effectively prevented from occurring. The ducts are adapted to be heated to a temperature substantially higher than the temperature of the steel band product. In addition, there is provided at least one vacuum sealing station with rolls rotatably mounted in the interior of a casing and a complementary sealing bar mounted in a complementary engagement relationship with the rolls having a close gap therebetween. A side panel is mounted self-adjustably in sliding motion in the longitudinal direction along the axes of the rolls on the opposite ends thereof, and heaters are provided to heat the rolls, sealing bar and side panel, respectively.

Vacuum evaporation coating equipment

Disclosed is a combined continuous plating apparatus for hot-dip plating and vacuum deposition plating characterized in that the outlet of the gas reduction annealing furnace of a conventional continuous hot-dip plating apparatus and the inlet of the seal roll chamber of a known continuous vacuum deposition plating apparatus are connected through a pressurized chamber in order to prevent invasion of hydrogen-containing reduction gas into the vacuum deposition chamber, whereby is prevented the possibility of the hydrogen-containing gas causing an explosion should air leak into the vacuum deposition chamber.

Combined continuous plating apparatus for hot-dip plating and vacuum

In a continuous vacuum deposition plating of a metal strip, thinner coating at the edges can be prevented by maintaining the pressure of the deposition chamber in which an evaporation chamber is housed at a properly higher level than the pressure of the evaporation chamber.

Method of controlling deposition amount distribution in a vacuum

In the continuous vapor deposition coating of a metal strip, the coating amount can be rapidly changed by keeping the vapor flow at acoustic velocity and changing the cross-sectional area of the vapor path.

Growing community of inventors

Sakai, Japan

Toshiharu Kittaka