摘要:
A high-strength, high damage-resistant rail made of 0.6 to 0.85 wt % C, 0.1 to 1.0 wt % Si, 0.5 to 1.5 wt % Mn, 0.035 wt % or less P, 0.040 wt % or less S, and 0.05 wt % or less Al, with the balance being Fe and inevitable impurities, and having corner and head side portions having a Brinell hardness of 341 to 405, and a head top portion in which a Brinell hardness of a site 20-mm distant from the central portion of the head top portion in a width direction is 341 to 405, and a hardness of the central portion of the head top portion is at least 10 lower in Brinell hardness than that of the site 20-mm distant from the central portion.
摘要:
In a method of electroplating tin utilizing an acidic electrolyte, prior to the electroplating step, a steel plate is subjected to a cathodic treatment in a treating bath for producing dense and continuous tin layers. The treating bath comprises an aqueous solution containing sulfuric acid and gluconic acid, water soluble salts thereof or a mixture thereof in the case of a pickling bath and caustic soda or sodium orthosilicate and one or more of water soluble oxyacid or water soluble salts thereof and a cheleting agent having cheleting capability in an alkaline region in the case of a degreasing bath.
摘要:
Liquid hydrocarbon containing substance such as crude oil, fuel oils and heavy oils or solid hydrocarbon containing substance such as coal and plastic scraps or discards is used as the source of hydrocarbon. Gas containing hydrocarbons produced by the heat decomposition of the source of hydrocarbon, or a gas mixture produced by admixing a gas produced by gasifying, atomizing or pulverizing the source of hydrocarbon with coke oven gas or a gas produced by heat decomposing the source of hydrocarbon by the action of steam containing oxygen, or by the action hydrogen, is admixed with furnace top gas discharged from the top of a reducing furnace and containing CO2 and H2O, and the resulting gas mixture is converted into the reducing gas consisting essentially of CO and H2 while the gas mixture is maintained at a predetermined high temperature.
摘要:
Colorless chromate film having good corrosion resistance and adhesive property on Aluminium, Aluminium alloy or Aluminiumcoated steel when these materials are subjected to a pretreatment stage wherein the material is rinsed with hot water after de-oiling and dried while the water film still lying on the surface is wiped by drawing rolls, a treatment stage wherein the material is processed with an aqueous solution of about 2 to 10g/l of CrO3, 0.05 to 1g/l Cr 3, 0.2 to 5g/l F , 0.01 to 5g/l of Ferricyanide and/or Ferrocyanide, 0.01 to 1g/l Al 3 and a post treatment stage wherein the material is processed with an aqueous solution containing water soluble copolymer of itaconic acid and acrylonitrile.
摘要:
Apparatus for assembling blocks of a hull which comprises as many carriages as there are floor plates to be welded, the carriages being arranged on at least one pair of parallel rails fixedly mounted on a standard bed, each carriage comprising a pair of wheel frames, a horizontal frame, a vertical frame, and a tiltable frame. The horizontal frame is provided with as many longitudinal member sockets and fixing devices as there are lower longitudinal members to be welded, and first and second floor plate sockets and a floor plate fixing device. The vertical frame is provided with a pivotable jig on its upper portion. The tiltable frame is pivotable about the upper end of the vertical frame and is provided with as many longitudinal member socket and fixing devices as there are upper longitudinal members to be welded. When respective cylinders for the first and second floor plate sockets, the pivotable jigs, the floor plate fixing devices and the longitudinal member socket and fixing devices are actuated, a girder, the floor plates and the upper and lower longitudinal members are located in proper alignment and position, and they are then directly subjected to the process of regular welding.
摘要:
When one or more rare earth metals or their alloys are added into liquid steel in an intermediate vessel disposed between a ladle and a mold, the resulting steel exhibits excellent impact property.
摘要:
The invention relates to an improved joint structure used for jointing steel pipe pile pieces. The lower pile piece is provided with a stopper member which is secured on the inner wall of the pile at a position slightly lower than the joint and edge portion thereof and whose upper surface has an angle of inclination under 90*. The upper pile piece is provided with a joint metal piece which is secured on the inner wall of the pile piece has a straight portion and a reduced diameter portion and whose edge is cut to an angle so that in the normal engaging positions the edge comes into close contact with the inclined surface of the associated stopper member, thus preventing the phenomena of sideslipping between the upper and lower pile pieces. The band is fit on either the upper or lower pile pieces (preferably on the upper pile piece), serving as a guide for the welding device that travel along the outer periphery of the pile.
摘要:
An X-ray examination system for examining the welded portions at both ends of steel pipes which is characterized in that there are provided between two linearly arranged roller conveyor lines an X-ray examination chamber and a control chamber for controlling the travel of steel pipes and the setting of two X-ray penetration devices; a plurality of turning rollers are arranged along both roller conveyor lines to rotate steel pipes in the circumferential direction; the turning rollers closest to both crosswise sides of the X-ray examination chamber and each provided with an automatic welded seam detector including a microswitch so as to stop rotating steel pipes at a prescribed peripheral angle, whereby the welded portion of the forward end of either of two adjacent ones of a plurality of steel pipes successively carried on the roller conveyor lines and the welded portion of the rear end of the other of said two adjacent steel pipes are examined in the examination chamber by two X-ray penetration devices operated under the remote control effected in the control chamber.
摘要:
The longitudinal ends or edges of a large plate composed of a plurality of unit plates welded together are not uniform or even and therefore the large plate cannot readily be utilized in that condition. In other words, the uneven portions on both ends of such a large plate must be cut to produce parallel ends. A cutting apparatus for large plates is provided, which mainly comprises a pair of rails disposed along the ends of a large plate and extending in the longitudinal direction thereof, a pair of cutting machines mounted on the rails to travel thereon, and a deviation detector for detecting the amount of deviation of position of a stopped large plate, whereby in accordance with the value of a detected deviation, the two rails are rotated in a parallel relation over the surface of the large plate to determine the cutting lines along the ends of the large plate, and the cutting devices are then brought into operation to remove the desired amount from both ends of the plate to produce the parallel ends.
摘要:
Compressed air is blown through a hole formed at one end of a transverse bulkhead into the clearance formed between a longitudinal bulkhead and a transverse bulkhead to test the water tightness of the weld zones formed thereat. Every block which is built as the hull construction based on known block system progresses, is tested and its water tightness confirmed thereby.