Patents Assigned to Pohang Iron & Steel Co., Ltd.
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Patent number: 5653821Abstract: A method for manufacturing an oriented electrical steel sheet includes the step of preparing a steel slab composed of in weight %: 0.035-0.050% of C, 2.9-3.3% of Si, less than 0.016% of P, 0.011-0.017% of soluble Al, 0.0080-0.012% of N, less than 0.007% of S, 0.06-0.18% of Ni+Cr, less than 0.32% of Mn with an Mn/S ratio of 20 or more, less than 0.6% of Cu with a Cu/Mn ratio of 1.5 or more, and balance of Fe and other inevitable impurities. The steel slab is heated at a temperature of 1250.degree.-1320.degree. C., and then hot rolled. The hot rolled slab is then cold rolled in two stages to a final sheet thickness, with a decarburization annealing being carried out at an intermediate thickness. The decarburized cold rolled sheet is coated with an annealing separator containing MgO as the main ingredient and then a finish annealing treatment is conducted, thereby obtaining a magnetically superior oriented electrical steel sheet.Type: GrantFiled: July 7, 1995Date of Patent: August 5, 1997Assignees: Pohang Iron & Steel Co., Ltd., Research Institute of Industrial Science & TechnologyInventors: Gyu Seung Choi, Chung San Lee, Jong Soo Woo, Byung Deug Hong
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Patent number: 5647922Abstract: A high manganese steel having superior hot workability is disclosed, in which small amounts of the alloying elements are added into a high manganese steel of Fe-Mn-Al-C system, so that the rupture strength of the grain boundaries of columnar crystals can be improved, thereby realizing an improved hot workability. Further, a process for manufacturing a high manganese hot rolled steel sheet is disclosed, in which the above mentioned high manganese steel is subjected to be controlled the initial hot rolling conditions during a hot rolling, so that large cracks would not be generated on the edges and on the surface of the hot rolled steel sheet. The process for manufacturing a hot rolled high manganese steel without any cracks includes the following the steps. That is, the process includes the steps of: preparing the ingot or the continuous casting slabs of the conventional Fe-Mn-Al-C steel with one or more elements selected from a group consisting of 0.0005-0.04% of B, 0.0005-0.050% of Ti, 0.0005-0.Type: GrantFiled: November 22, 1995Date of Patent: July 15, 1997Assignees: Pohang Iron & Steel Co., Ltd., Research Institute of Industrial Science & TechnologyInventors: Tai Woung Kim, Young Gil Kim, Shin Hwa Park
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Patent number: 5642468Abstract: A robot manipulator which includes an upper arm having a wrist coupled to one end of the upper arm. The wrist includes at least three rotational axes of articulation with one of the rotational axes offset from an intersection of the other two rotational axes. Three twist angles are formed between the respective rotational axes. The value of these twist angles is optimized to orientate the three rotational axes of articulation in a configuration minimizing the space which the robot manipulator cannot reach.Type: GrantFiled: February 7, 1996Date of Patent: June 24, 1997Assignees: Pohang Iron and Steel Co., Ltd., Research Institute of Industrial Science & TechnologyInventors: Kwang Sae Lee, Young Il Youm
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Patent number: 5610310Abstract: The present invention describes novel cyclic diol derivatives represented by formula I and II: ##STR1## in which Y represents O, S, SO, SO.sub.2, (CH.sub.2).sub.m wherein m is zero or an integer of 1 to 5, or NR.sup.a group wherein R.sup.a is hydrogen, lower alkyl, lower alkoxycarbonyl, aryl, arylalkyl or acyl;R.sup.1 represents an alkyl or alkylcarbamoyl group;R.sup.2 represents a group having formula T--(CH.sub.2).sub.n --V (X.sup.-)q, wherein T refers to a simple covalent bond, a CO, PO.sub.3.sup.-, C(O)O, or CONR.sup.b group wherein R.sup.b is hydrogen, lower alkyl or acyl;n refers to an integer of from 1 to 10;V represents either (i) the group indicated by formula --.sup.+ NR.sup.5 R.sup.6 R.sup.7 wherein R.sup.5, R.sup.6 and R.sup.7 stands for identical or different lower alkyl group, or two or three of R.sup.5, R.sup.6 and R.sup.7 taken together with the adjacent nitrogen form heterocyclic ammonio group, or (ii) the group indicated by the formula ##STR2## wherein R.sup.Type: GrantFiled: June 7, 1995Date of Patent: March 11, 1997Assignees: Pohang Iron & Steel Co., Ltd, Research Institute of Industrial Science & TechnologyInventors: Soon H. Woo, Sung K. Chung, Soo H. Ban, Byoung E. Kim, Si H. Kim
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Patent number: 5584910Abstract: A process for producing molten pig iron or molten steel pre-products from charging substances formed of iron ores and fluxes and at least partially comprising fines, wherein the charging substances are directly reduced to sponge iron in at least one reduction zone by the fluidized layer process, the sponge iron is melted in a melting-gasifying zone under supply of carbon carriers and oxygen-containing gas, and a CO and H.sub.2 -containing reducing gas is produced, which is injected into the reduction zone, is reacted there, is withdrawn as an export gas and is supplied to a consumer, is to be improved with a view to rendering feasible the use of fine ore in an economic manner.Type: GrantFiled: October 20, 1993Date of Patent: December 17, 1996Assignees: Pohang Iron & Steel Co., Ltd., Research Institute of Industrial Science & Technology, Voest-Alpine Industrieanlagenbau GmbHInventors: Werner Kepplinger, Panajiotis Matzawrakos, Johannes Schenk, Dieter Siuka, Christian Bohm
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Patent number: 5575973Abstract: A low decarburization high toughness spring steel for an automobile suspending spring, and a manufacturing process therefor, are disclosed. In this steel, the effect of the sag resistance promoting element (Si) is maximized without reducing the carbon content, so that the problems of the decarburization and the lowering of the toughness (caused by the addition of silicon) should be solved during the manufacturing of the spring steel. The spring steel of the present invention is composed of in weight %: 0.5-0.7% of C, 1.0-3.5% of Si, 0.3-1.5% of Mn, 0.3-1.0% of Cr, 0.05-0.5% of V and/or Nb, less than 0.02% of P, less than 0.02% of S, 0.5-5.0% of Ni, and other indispensable impurities, the balance being Fe.Type: GrantFiled: August 9, 1995Date of Patent: November 19, 1996Assignees: Pohang Iron & Steel Co., Ltd., Research Institute of Industrial Science & TechnologyInventors: Hae C. Choi, Won J. Nam, Jong K. Choi, Soo D. Bark, Jong H. Choi, Jang G. Kim
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Patent number: 5576067Abstract: A CO gas detecting sensor for detecting the existence or absence of CO gas and a manufacturing process therefor are disclosed. The CO gas detecting sensor includes: a sintered zinc oxide body; a copper oxide coating layer formed on a side of the sintered zinc oxide body; a positive metal electrode layer (a first electrode layer) electrically connected to the copper oxide coating layer; and a negative metal electrode layer (a second electrode layer) formed on the other side of the sintered zinc oxide body. The CO gas detecting sensor according to the present invention is superior in the preference for CO gas, and has an improved measuring repeatability, as well as a superior sensitivity.Type: GrantFiled: March 1, 1995Date of Patent: November 19, 1996Assignees: Pohang Iron & Steel Co., Ltd., Research Institute of Industrial Science & TechnologyInventors: Masaru Miyayama, Byoung C. Shin
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Patent number: 5571343Abstract: An austenitic stainless steel and a manufacturing process therefor are disclosed, in which, instead of the expensive Ni, there are added Cu as an austenite (.tau.) stabilizing element, and tiny amounts of Ti as a ferrite forming element and B for improvement of high temperature hot workability, so that the optimum Md.sub.30 temperature and the optimum delta-ferrite content can be controlled, thereby improving the formability, the season cracking resistance, the hot workability and the high temperature oxidation resistance, and reducing the surface defects during the hot rolling and saving the manufacturing cost by reducing the content of Ni. The austenitic stainless steel according to the present invention includes in weight %: less than 0.07% of C, less than 1.0% of Si, less than 2.0% of Mn, 16-18% of Cr, 6.0-8.0% of Ni, less than 0.005% of Al, less than 0.05% of P, less than 0.005% of S, less than 0.03% of Ti, less than 0.003% of B, less than 3.0% of Cu, less than 0.3% of Mo, less than 0.Type: GrantFiled: April 19, 1995Date of Patent: November 5, 1996Assignees: Pohang Iron & Steel Co., Ltd., Research Institute of Industrial Science & TechnologyInventors: Do Y. Ryoo, Yong H. Lee, Jae S. Park, Hyun C. Kim, Eung J. Kim
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Patent number: 5567379Abstract: A plant is provided for producing molten pig iron or molten steel pre-products from lumpy, iron-ore-containing charging substances. The plant comprises a reduction shaft furnace for receiving lumpy, iron-ore-containing charging substances, the plant including a melter gasifier for receiving the reduction product formed in the reduction shaft furnace. The plant also includes a first charging device for at least one of iron ore and ore dust and a second charging device for solid carbon carriers, the melter gasifier being provided with a device for flow-connecting the first charging device for at least one of iron ore and ore dust and the second charging device for charging carbon carriers to at least one dust burner.Type: GrantFiled: May 25, 1995Date of Patent: October 22, 1996Assignees: Voest-Alpine Industrieanlagenbau GmbH, Pohang Iron & Steel Co., Ltd., Research Institute of Industrial Science & Technology, Incorporated FoundationInventors: Leopold W. Kepplinger, Panajiotis Matzawrakos, Johannes Schenk, Dieter Siuka
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Patent number: 5520748Abstract: A process for manufacturing an Alnico system permanent magnet is disclosed in which the alloy powder of the Alnico system having the proper composition is manufactured through a rapid solidification process, so that the crushability and the formability should be superior, the sintered density should be high, and the magnetic properties should be excellent, as well as cheap in its manufacturing cost and simple in its manufacturing process. An alloy of Alnico system is subjected to a rapid solidification with a spinning solidifier wheel speed of 6-40 m/sec, thereby manufacturing a microcrystalline rapidly solidified powder. The powder is ground into a finer powder, and then a press-forming is carried out. Then a sintering is carried out at a temperature of 1100.degree.-1350.degree. C. for 0.5-4 hours. Then based on a single heat treatment, an external magnetizing force of 1-15 kOe is applied in a temperature range of 600.degree.-1000.degree. C., thereby carrying out a heat treatment under a magnetizing force.Type: GrantFiled: March 9, 1995Date of Patent: May 28, 1996Assignees: Pohang Iron & Steel Co., Ltd., Research Institute of Industrial Science & TechnologyInventors: Choong J. Yang, Seung D. Choi, Woo Y. Lee, Young G. Son
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Patent number: 5507189Abstract: Apparatus and a method for evaluating the plane strain stretch formability for thin steel sheets used in automotive bodies to provide easy evaluation of the plane strain stretch formability. The apparatus includes: a lower die and an upper die with a lock bead installed thereon. A rectangularly shaped test specimen is inserted between the upper and lower dies and, and is clamped by means of the lock bead along the circumferential edge of the test specimen, so that the material of the test specimen can be moved into the upper die. A punch is elevated to apply a stretch forming force on the test specimen, and then, the plane strain stretch formability is evaluated based on the fracture limit punch height at the instant of the fracture. The punch has a saddle-like, semi-cylindrical shape.Type: GrantFiled: August 25, 1994Date of Patent: April 16, 1996Assignees: Pohang Iron & Steel Co., Ltd., Research Institute of Industrial Science & TechnologyInventors: Young S. Kim, Jeong C. Kim, Won J. Choi, Rae W. Chang, Ki S. Kim, Moon H. Yu
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Patent number: 5457230Abstract: The present invention discloses a method for removing iodine compounds from acetic acid, in which the iodine compound is removed by using a solid adsorbent in the form of an activated carbon fiber having a large strength, a large bulk density, and a large specific surface, so that the treatment of large amounts should be possible, that the acetic acid should not be contaminated during the extraction of foreign materials from the adsorbent, and that the adsorbent can be repeatedly used by regenerating it. The method includes the steps of: preparing a filter in the usual manner by using an activated carbon fiber as the adsorbent; and making acetic acid containing an iodide pass through the activated carbon fiber filter, whereby the iodide in acetic acid is removed by being adsorbed by the activated carbon fiber filter.Type: GrantFiled: November 17, 1994Date of Patent: October 10, 1995Assignees: Pohang Iron & Steel Co., Ltd., Research Institute of Industrial Science & TechnologyInventors: O. Bong Yang, Young G. Kim, Jae C. Kim, Jae S. Lee, Hee J. Yang
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Patent number: 5453136Abstract: A process for manufacturing a high magnetic flux density grain oriented thin electrical steel sheet having superior magnetic properties and for use on transformers is disclosed. Proper amounts of Sn, Cr, Ni and Mo are added into a high magnetic flux density grain oriented electrical steel sheet in which AlN and MnS are utilized for inhibiting the growth of the primary recrystallization grains. The process results in the production of a high magnetic flux density grain oriented thin electrical steel sheet showing a stabilized recrystallization, a high productivity and a high yield.Type: GrantFiled: August 9, 1993Date of Patent: September 26, 1995Assignee: Pohang Iron & Steel Co., Ltd.Inventors: Jong K. Kim, Sung J. Lee, Young J. Yoon
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Patent number: 5445668Abstract: In a method of producing molten pig iron from lumpy, iron-ore-containing charging substances, the latter are reduced in a reduction shaft furnace by means of a reducing gas, wherein the iron sponge particles obtained are melted in a melter gasifier under supply of coal and oxygen-containing gas under simultaneous formation of the reducing gas, and the reducing gas is returned to the reduction zone of the shaft furnace.To enable charging of larger amounts of fine ore and/or ore particles, such as oxidic iron fine dust incurred in a metallurgical plant, in addition to the charging substances, the fine ore and/or the ore dust is supplied with solid carbon carriers to at least one dust burner working into the melter gasifier and is reacted in a substoichiometric cumbustion reaction.Type: GrantFiled: May 20, 1993Date of Patent: August 29, 1995Assignees: Voest-Alpine Industrieanlagenbau G.m.H, Pohang Iron & Steel Co. Ltd.Inventors: Leopold W. Kepplinger, Panajiotis Matzawrakos, Johannes Schenk, Dieter Siuka
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Patent number: 5441699Abstract: An apparatus for automatically analyzing various solutions which are used in the production lines of various industrial fields. Particularly, in the case where the ingredients of a solution is to be analyzed, the test sample is taken in an automatic manner, and carried over a long distance. The carried test sample is subjected to an automatic pre-treatment and an automatic ingredient analysis. Thus the ingredients of a solution can be analyzed in a speedy and accurate manner. Further, the results of the analysis are treated with an on-line real time to be fed back in a speedy manner, and therefore, it is made possible to strictly control the solution ingredients, thereby contributing to the improvement of the quality of products. Furthermore, the expensive analyzing instruments can be protected from corrosion.Type: GrantFiled: December 28, 1993Date of Patent: August 15, 1995Assignees: Pohang Iron & Steel Co., Ltd., Research Institute of Industrial Science & TechnologyInventors: Jai-Choon So, Hae-Il Kwak, Kyu-Hae Kwang, Yong-Hwan Cho, Ki-Jin Eom, Sa-Ryong Pack
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Patent number: 5431753Abstract: An austenitic high manganese steel having superior formability, strengths and weldability, and a process for manufacturing the steel, are disclosed. The superior formability of the steel is suitable for use on automobiles and electronic panel. The steel has a composition of (in weight %) less than 1.5% of C, 15.0-35.0% of Mn, 0.1-6.0% of Al, and the balance of Fe and other indispensable impurities. The size of the austenite grains is less than 40.0 .mu.m, and, one or more elements are added by selecting them from a group consisting of less than 0.60% of Si, less than 5.0% of Cu, less than 1.0% of Nb, less than 0.5% of V, less than 0.5% of Ti, less than 9.0% of Cr, less than 4.0% of Ni, and less than 0.2% of N, thereby providing an austenitic high manganese steel having superior formability, strengths and weldability.Type: GrantFiled: August 26, 1993Date of Patent: July 11, 1995Assignees: Pohang Iron & Steel Co. Ltd., Research Institute of Industrial Science & TechologyInventors: Tai W. Kim, Jae K. Han, Rae W. Chang, Young G. Kim
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Patent number: 5409748Abstract: A heat radiating tube for an annealing furnace is disclosed. An aluminide layer and an aluminum diffusion sublayer are formed by an aluminum diffusion coating method on one side or both sides of the tube portions which are subjected during use to high temperature oxidation corrosion. Subsequently, a coating of MCrAlY is applied on selected inside portions exposed to the combustion gas flame collision in order to reinforce the bonding strength of the protective coating. A layer of ceramic is then coated thereupon. Prior to applying the MCrAlY and ceramic coatings, the tube surface to be coated is ground to a depth equal to the coating thicknesses in order to make the heights of the coated layer and the surface of the remaining portions of the tube even each other.Type: GrantFiled: December 27, 1991Date of Patent: April 25, 1995Assignees: Pohang Iron & Steel Co., Ltd., Research Institute of Industrial Science & TechnologyInventors: Jin W. Song, Soon Y. Whang, Byong K. Sung
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Patent number: 5401332Abstract: A grain oriented electrical steel having superior magnetic properties and for use in transformers and electrical generators, and a manufacturing process thereof are disclosed. Cu and P are mixedly added in the melting stage of a silicon steel containing MnS and AlN as grain growth inhibitors, and in this way, the magnetic properties are improved. The chemical composition of the steel sheet of the present invention are: 2.50-4.00% of Si, 0.03-0.15% of Mn, 0.030-0.300% of Cu, and 0.020-0.200% of P, the balance being Fe, all in weight %. The grain oriented electrical steel sheet of the present invention shows a low iron loss and a high magnetic flux density, and is cold-rolled to a thickness range of 0.15-0.27 mm.Type: GrantFiled: February 9, 1993Date of Patent: March 28, 1995Assignees: Pohang Iron & Steel Co., Ltd., Research Institute of Industrial Science & TechnologyInventors: Chung S. Lee, Jong S. Wo
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Patent number: 5334416Abstract: A heat resistant stainless steel coated by diffusion of aluminum and a method of aluminum diffusion coating for heat resistant stainless steels containing nickel and chromium. The stainless steel is buried in a diffusion coating pack powder composed of an aluminum source, an activator and inert filler materials. The coating is heat treated to form a chromium-rich intermediate layer without forming an interdiffusion layer containing aluminide precipitates under an aluminide layer.Type: GrantFiled: December 23, 1992Date of Patent: August 2, 1994Assignees: Pohang Iron & Steel Co., Ltd., Research Institute of Industrial Science & TechnologyInventors: Byeong G. Seong, Soon Y. Hwang, Jin H. Song, Kyoo Y. Kim
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Patent number: 5284782Abstract: A process for formation of a delta-doped quantum well field effect transistor is disclosed, and the transistor includes: a substrate, a super lattice, a buffer layer, quantum wells, a cap layer, and an ohmic layer. Then a drain, a source and a gate are formed on the ohmic layer. Each of the quantum wells is formed in such a manner that: a first GaAs layer is formed by applying a metalorganic chemical vapor deposition process under a low reaction pressure; then an Si impurity such as SiH4 or Si2H6 is delta-doped into the layer; and then, a second GaAs layer is formed by applying the metalorganic chemical vapor deposition process under the same condition, thereby forming the GaAs/AlGaAs delta-doped quantum well field effect transistor of the present invention, having the advantage of economy.Type: GrantFiled: August 17, 1992Date of Patent: February 8, 1994Assignees: Pohang Iron & Steel Co., Ltd., Research Institute of Industrial Science & TechnologyInventors: Yoon H. Jeong, Dong H. Jeong, Kyeong S. Jang