Abstract: A method of producing carbon materials having high density and strength, which method includes starting from a calcined product or its classified product having particular properties obtained by calcining a residue after heat treatment, solvent extraction and filtration of coal tar pitch at 250.degree.-500.degree. C. in an inert gas atmosphere, and then molding, firing and graphitizing it.

Abstract: An unbonded PC steel strand used for posttensioning concrete comprising a PC steel strand composed of a plurality of stranded wires, a zinc plated layer on the outer surface of the PC steel strand, a greaselike filler applied around the zinc plated layer, and a synthetic resin sheath covering the zinc and filler coated PC steel strand. A method of manufacturing the unbonded PC steel strand comprising steps of pickling and water washing the PC steel strand, coating the outer surface of the PC steel strand with flux, plating the outer surface of the PC steel strand with zinc, applying a greaselike corrosion inhibitor to the surface of the zinc plated layer and sheathing the PC steel strand with an outer synthetic resin sheath.

Abstract: A cooling pad for use in a continuous casting apparatus for the production of cast sheets. The pad is provided with plural water supply and discharge holes satisfying the particular relations on the arrangement thereof. By using such a cooling pad, a filmy cooling water flow is uniformly and stably formed in the casting.

Abstract: An electrolytic processing device has an electrolytic tank which comprises separably coupled upper and lower units. The upper and lower units can be coupled to each other to form a single electrolytic tank when electrolytic processing is to be performed. On the other hand, the upper and lower units can be replaced with other units independently. This allows the electrolytic solution in the lower unit to be changed simply by replacing the lower unit with another unit with a different electrolytic solution, without the need for draining and washing the lower unit used previously.

Abstract: Continuous casting facilities generally including a pair of moulds with a rail on each side thereof. Self-propelled tundish cars each carrying a tundish with a detachable immersion nozzle ride on the rails. The apparatus includes a truck running on the rail opposite the operator's side of the moulds connectable with one of the tundish cars and carrying an immersion nozzle exchanger. A connecting piece feeder, a powder feeder, and an immersion nozzle preheater are also mountable on the truck. Equipment interferences are eliminated by the specific structures and the operator's view of the moulds is not obstructed.

Abstract: A connector, for example for connecting a tubular member such as a pipe, comprises a male member which has an external frusto-conical surface provided with a thread and a female member having an internal frusto-conical surface provided with a thread for engagement will the thread of the male member. The members are provided with generally radially directed sealing surfaces which are brought into sealing abutment under an axially directed compressive force when the members are fully engaged together. To improve the loading of the threads of the members on engagement of the members and on application of a tensile load to the engaged members, the axial thickness of the thread of at least one of the members in one or both of the portions of the thread adjacent the ends thereof is reduced to increase the flexibility of the thread and therefore reduce the load sustaining ability of the thread.

Abstract: Highly corrosion resistant plated steel strips or sheets adapted for phosphate treatment and cathodic electrodeposition and intended for use in automobiles, are produced by electroplating at least one surface of a steel strip with an alloy consisting essentially of 0.0003 to 15% by weight of phosphorous, balance essentially iron, in a plating bath containing Fe.sup.2+ ions in an amount of from 0.3 mol/liter to the solubility limit and hypophosphorous acid and/or a hypophosphite in an amount of 0.001 to 25 g/liter expressed as NaH.sub.2 PO.sub.2.H.sub.2 O at a pH of 1.0 to 5.0, a temperature of 30.degree. to 60.degree. C., and a current density of from more than 20 to 200 A/dm.sup.2, preferably 40 to 150 A/dm.sup.2. A top coat can be applied thereover, of one element selected from the group consisting of Ni, Zn, Mn, and Ti, deposited on the Fe-P plating layer to a build-up of 5 to 50 mg/m.sup.2.

Abstract: A laser butt welding apparatus including a pair of clamp elements at least one of which is movable reciprocally along the steel strip-feed line direction and which are adapted to clamp the edge portions of preceding and trailing steel strips, a shear which is advanceable and retractable between the pair of the clamp elements in a perpendicular direction to the line and cuts the edge portions of the preceding and trailing steel strips, structure for butting the cut faces of the preceding and trailing steel strips while being clamped by means of the clamp elements, and a laser torch adapted to condense a laser beam from a laser oscillator on an off-line at a weld zone and movable in a width direction of the steel strips to be welded together.

Abstract: A low load burning burner comprising inner air flow nozzles, outer air flow nozzles and a fuel gas nozzle, and further having a motive air supply means, which is operated at the low load burning of a heating furnace, can maintain the furnace temperature uniform, and can heat materials arranged in the width direction of the furnace to a uniform temperature along the width direction of the furnace.

Abstract: An austenitic stainless steel welded metal layer having the given composition containing delta-ferrite phase is previously overlay welded as an intermediate layer prior to overlay welding of a surface layer of stainless steel, nickel alloy or the like on a base metal of carbon steel or low alloy steel. In the said composition, by making the ratio of Creq/Nieq to be more than 1.85, the disbonding is prevented and by making Creq to be less than 26% and the content of delta-ferrite phase to be less than 20%, the deterioration of flexural elongation is prevented. The present invention is applicable to the lining on an inner surface of a chemical reactor vessel, such as a desulfurizing reactor for petroleum-refining to be used under a high-temperature, high-pressure hydrogen environment.

Abstract: A laser-welding apparatus including a pair of clamps at least one of which is movable reciprocally along the steel strip-feed line direction and which are adapted to clamp the edge portions of preceding and trailing steel strips, a shear which is advanceable and retractable between the pair of the clamps in a perpendicular direction to the line and cuts the edge portions of the preceding and trailing steel strips, a device for butting the cut faces of the preceding and trailing steel strips while being clamped by means of the clamps, a device for continuously feeding a filler wire at a weld zone at which the laser beam is condensed, and a laser torch adapted to condense a laser beam from a laser oscillator on an off-line at a weld zone and movable in the width direction of steel strips to be welded together.

Abstract: A cutter for a welding apparatus for cutting a welding workpiece upon welding. In order to facilitate the positioning of the cutter during the movement of the cutter for the cutting operation and to make the entire apparatus small-sized, a shear frame is formed with substantially the shaped of a C, and the opposing portions of the C-shaped shear frame are connected by a connecting rod, enabling the reaction force during the cutting operation to be resisted by the shear frame itself.

Abstract: A cold rolled dual-phase structure steel sheet having an excellent deep drawability is disclosed, which consists of ferrite phase and low temperature transformation product phase and comprises 0.001-0.008 wt % of C, not more than 1.0 wt % of Si, 0.05-1.8 wt % of Mn, not more than 0.15 wt % of P, 0.01-0.10 wt % of Al, 0.002-0.050 wt % of Nb and 0.0005-0.0050 wt % of B provided that the value of Nb (%)+10B (%) is in a range of 0.010-0.080%, and, if necessary, 0.05-1.00 wt % of Cr and the balance being substantially Fe with inevitable impurities. This steel sheet is manufactured by hot and cold rolling a steel slab with the above chemical composition and continuously annealing the resulting steel sheet in such a manner than the steel sheet is heated and soaked at a temperature from .alpha..fwdarw..gamma. transformation point to 1,000.degree. C. and then cooled at an average cooling rate of not less than 0.5.degree. C./sec but less than 20.degree. C.

Abstract: Disclosed herein is an apparatus for blowing a powdery refining agent into a refining vessel which is adapted to blow the powder into a molten metal bath of the refining vessel together with a refining gas by feeding the powder from a pressure vessel to a main pipe for the supply of the refining gas. The pressure vessel is connected to the main pipe through a plurality of transportation pipes each provided with an on-off valve and connected to a secondary gas pipe for introduction of the refining gas downstream of the on-off valve. The secondary gas pipe is provided with a flow control valve.

Abstract: Surface-treated steel strips suitable for electric resistance welding are prepared by forming a first layer of iron-nickel alloy on a steel strip, said first layer having a weight ratio of Ni/(Fe+Ni) in the range between 0.02 and 0.50 and a thickness of 10 to 5,000 angstroms, forming a second layer of tin or iron-tin-nickel alloy on said first layer by tin plating to a coating weight of 0.1 to 1 g/m.sup.2 of tin and optionally, causing the tin to reflow, and forming a third layer on said second layer by effecting an electrolytic chromate treatment, said third layer consisting essentially of metallic chromium and hydrated chromium oxide in a total amount of 5 to 20 mg/m.sup.2 calculated as elemental chromium. More preferably, the electrolytic chromate treatment is controlled such that at least 2 mg/m.sup.2 of metallic chromium is present in the third layer.

Abstract: The present invention relates to a method of producing compression molded coal to be used for the block charging for the coke oven operation wherein the raw material coal are initially compression molded, a part of said already compression molded coal is caused to remain in the molding box while the subsequent raw material coal is charged to be compression molded, and said compression molded coal is combined so that the compression molded coal may be produced continuously. At the compression molding, the already compression molded coal may overcome the compression force applied to the subsequent compression molded coal due to its friction generated between the molded coals and the molding box. Further application of pressure to the pressing plate after the molding operation will cause the compression molded coal to be pushed out of the molding box.

Abstract: A duplex stainless steel seamless pipe can be inexpensively produced in high productivity and yield without causing cracks during the working steps in the plug mill process by a proper combination of the composition of the steel and the working conditions of a billet and a hollow piece for the production of the pipe.

Abstract: A steel strip heating furnace has a movable wall which can be positioned closer or farther away from the transverse edges of the steel in order to adjust the heat radiation applied to the opposing edges of the steel. The movable wall extends parallel to the longitudinal axis of a course along which the steel is transported through the furnace. The movable wall constitutes part of a ceiling of a furnace body and can be shifted vertically toward and away from the transverse edges of the steel so as to adjust the high-temperature heat radiation transmission area about the opposing transverse edge and thus control the heat applied to the corresponding section of the steel. Also, it is especially advantageous to provide means for cooling the movable wall so as to adjust the heat radiation therefrom. Therefore, the heating furnace can control the heat applied to the transverse edges of the steel so that the entire surface of the steel can be heated uniformly.

Abstract: A method of controlling the rolling efficiency in a continuous hot rolling process including the steps of inputting a total weight of and the time intervals of slabs already extracted from a heating furnace in a period from the present time up to any previous time, a total weight and a forecast furnace residence time of slabs charged in the heating furnace and a total weight of any number of slabs to be charged, and calculating the desired rolling efficiency of the slabs to be charged to thereby control the overall average rolling efficiency to a predetermined value. With such a method, the total weight of the slabs to be rolled in a unit time is maintained to a predetermined value.

Abstract: A steel-making process in a converter, which includes using a carbon monoxide gas as an agitating gas supplied from a position lower than molten metal bath level.