Patent application number | Description | Published |
20080314109 | Plug for use in piercing mill - A plug has a tip end portion, a taper portion, and a middle portion. The surface of the tip end portion is a spherical surface whose radius of curvature is R | 12-25-2008 |
20090038359 | Method of manufacturing seamless pipe or tube - A billet is provided on a pass line between a pusher and a plug, and the billet is advanced and caught between a plurality of inclined rolls. At least between when said caught billet contacts said plug and when the piercing and rolling reaches a steady state, the advancing speed of the billet is not less than the advancing speed of the billet when the piercing and rolling is carried out without pushing the billet forward by the pusher in the steady state. By this manufacturing method, inner surface defects at a tip end of a hollow shell can be restrained. | 02-12-2009 |
20100011831 | PIERCING MILL - A piercing mill includes a plurality of inclined rolls, a plug, a pusher, and an undriven guide roll. The pusher pushes a round billet from the rear end at least until the round billet advances for a prescribed distance after contacting the inclined rolls. The guide roll is between the inclined rolls and the pusher and includes a roll shaft and a roll surface, with the roll shaft arranged obliquely with respect to a pass line PL. The sectional shape of the roll surface is a concave arch shape. The round billet is rotated by the guide roll and the friction force generated when the round billet contacts the inclined rolls is reduced. Consequently, the wear of the inclined rolls can be restrained if the round billet is pierced and rolled while it is pushed in between the inclined rolls using the pusher. | 01-21-2010 |
20100089111 | Piercer, Plug and Method of Manufacturing Seamless Pipe or Tube | 04-15-2010 |
20100107714 | PUSHER DEVICE FOR PIERCING AND ROLLING AND METHOD OF MANUFACTURING SEAMLESS PIPE OR TUBE USING THE SAME - A pusher device | 05-06-2010 |
20100175450 | METHOD OF PRODUCING SEAMLESS METAL TUBE AND PUNCH FOR USE THEREIN | 07-15-2010 |
Patent application number | Description | Published |
20080289388 | Piercing-rolling method and piercing-rolling apparatus for seamless tubes - [Objective] To provide a method and apparatus for seamless tubes in which the occurrence of material peeling can be prevented even when the skew angle δ and tube expansion ratio are increased. | 11-27-2008 |
20090064748 | Process for manufacturing a seamless tube - A high quality hollow shell in which the occurrence of internal surface flaws caused by the rotary forging effect and/or shear deformation is prevented by suppressing the rotary forging frequency and shear deformation in a transient region at the stage of billet gripping and a worsening of thickness deviations in the top portion of the hollow shell is also prevented is reliably produced with preventing miss-rolling such as incomplete billet gripping and troubles in bottom withdrawal and an increase in the outer diameter of the hollow shell in the bottom portion. A billet is pierced while being rotated and advanced to produce a hollow shell, from which a seamless tube is finally manufactured, using a pair of skew rolls, a pair of disk rolls, and a plug under such conditions that each of the ratio (Dg/d) of the diameter Dg of the gorge portion of the skew rolls and the outer diameter d of the billet, the ratio (Dd/d) of the diameter Dd of the groove bottom of the disk rolls and the outer diameter d of the billet, the ratio (Dd/Dg) of the diameter Dg and the diameter Dd, the inlet face angle θ | 03-12-2009 |
20090301155 | Method of manufacturing seamless pipes - Seamless pipes excellent in quality features with high productivity is made by a by carrying out piercing-rolling using a piercer provided with a pair of inclined rolls. The piercing-rolling is carried out under conditions such that the plug tip draft (TDFT) or the root of the product of the plug tip draft (TDFT) are controlled along with the number of billet revolutions (N), namely (TDFT×N) | 12-10-2009 |
20100000281 | Method for manufacturing seamless steel pipe made of high Cr-high Ni alloy steel - a billet made of high Cr-high Ni alloy, which contains, by mass percent, 20 to 30% of Cr, 30 to 50% of Ni, and at least one element selected from Mo and W with a value “Mo+0.5W” of 1.5% or more is heated under conditions satisfying the following formula (1), and then the billet is pierced and rolled using an inclined roll type piercing mill with a roll gouge circumferential speed of 2.28 m/sec or higher. This prevents melted rash on the inner surface and lengthens the plug life. | 01-07-2010 |
20120031534 | METHOD FOR PRODUCING HIGH-STRENGTH Cr-Ni ALLOY SEAMLESS PIPE - A method for producing a high-strength Cr—Ni alloy seamless pipe comprising preparing an alloy billet with a chemical composition consisting, by mass %, of C: 0.05% or less, Si: 1.0% or less, Mn: less than 3.0%, P: 0.005% or less, S: 0.005% or less, Cu: 0.01 to 4.0%, Ni: 25% or more and less than 35%, Cr: 20 to 30%, Mo: 0.01% or more and less than 4.0%, N: 0.10 to 0.30%, Al: 0.03 to 0.30%, O (oxygen): 0.01% or less, REM (rare earth metal): 0.01 to 0.20%, and the balance being Fe and impurities, and satisfying the formula N×P/REM≦0.10, wherein P, N and REM represent the contents (mass %) of P, N and REM, respectively. The pipe is hot worked using cross roll piercing, solution heat treated, and cold worked. The pipe is excellent in hot workability, stress corrosion cracking and does not laminate during cross piercing. | 02-09-2012 |
20120210761 | Plug, Piercing-Rolling Mill, and Method of Producing Seamless Tube by Using the Same - A plug includes a front edge portion having a convex curvature; a cylindrical portion having a truly or nearly cylindrical shape; a trunk portion having an outer diameter gradually increasing toward a rear edge thereof; a mandrel joint provided in a rear edge portion of the plug; a lubricant ejection hole running through the trunk portion from the mandrel joint that opens on the surface of the cylindrical portion; and a coating comprising oxides and Fe that is formed on the base metal surface of each of the front edge portion as well as the trunk portion by arc spraying using an iron wire. In this way, the plug can prevent inner surface flaws from occurring in a hollow blank that is deformed by piercing-rolling, and can extend its life without requiring a long time for making it. | 08-23-2012 |
20130115376 | ANTIOXIDANT AGENT, PROCESS FOR PRODUCING ANTIOXIDANT AGENT, AND PROCESS FOR PRODUCING METALLIC MATERIAL - There is provided an antioxidant agent capable of preventing scale from being produced on the surface of a heated metallic starting material more effectively than the conventional antioxidant agent. The antioxidant agent according to the present invention contains a plurality of glass frits having different softening points and an inorganic compound having a melting point not higher than 600° C. The inorganic compound mainly softens in the low-temperature range of about 600° C. The plurality of glass frits mainly soften in the low-temperature range of about 600 to 1300° C. Therefore, the antioxidant agent covers the surface of metallic starting material in a broad temperature range, oxidizes the surface of metallic starting material, and prevents the production of scale. | 05-09-2013 |
20130283879 | Ni BASE ALLOY PIPE STOCK AND METHOD FOR MANUFACTURING THE SAME - A method for manufacturing an Ni base alloy pipe stock comprises piercing and rolling a billet by use of Mannesmann piercing and rolling mill. The pipe stock has controlled amounts of C, Si, Mn, P, S, Cr, Ni, Mo, W, Cu, Al, N, with the balance being Fe. With the method, the following equations are satisfied, wherein values of T | 10-31-2013 |
Patent application number | Description | Published |
20090054279 | Two-Component Anti-Seizure Agent for Hot Metal Working Process, and Method of Manufacturing Seamless Pipe Using Thereof - The present invention provide a two-component anti-seizure agent for hot metal working process comprising the first aqueous solution and the second aqueous solution, wherein the first aqueous solution contains 10˜30 mass % of sodium silicate equivalent to anhydride to 100 mass % of total mass of the first aqueous solution, and the second aqueous solution contains at least one kind selected from a group consisting of: an organic acid and water-soluble amine salts thereof, an inorganic acid and water-soluble amine salts thereof, a water-soluble amine, a water-soluble alcohol, and a water-soluble metal chloride. When the two-component anti-seizure agent is applied onto disk-roll type guide shoes, it can be provided and maintained on the circumferential surface of the disk-roll type guide shoes without washed away by rolls' cooling water. Thereby, the anti-seizure agent does not adhere to rolls and the rolls and a pipe material do not cause slippage each other. Thus, it is capable to carry out piercing-rolling of the pipe material. | 02-26-2009 |
20090218014 | Method for Producing Duplex Stainless Steel Seamless Pipe - The present invention is to provide a method for producing duplex stainless steel seamless pipe in which a duplex stainless steel billet can be inhibited from generating an oxide scale on the surface thereof during heating and the generation of outer surface flaw can also be prevented. The billet is heated in the a heating furnace for 1.5 hours or more and 4.0 hours or less at a heating temperature of 1250° C. or more and 1320° C. or less while regulating the average concentration of sulfur dioxide (SO | 09-03-2009 |
20090301151 | LUBRICANT COMPOSITION FOR HOT METAL WORKING AND METHOD OF HOT METAL WORKING USING THE SAME - The present invention provides a lubricant composition for hot metal working which is capable of inhibiting generation of flaws on the surface of materials to be provided for hot metal working, and provides a method of hot metal working. The invention provides a lubricant composition for hot metal working comprising a plurality of glass frits respectively having different softening point from each other. | 12-10-2009 |
Patent application number | Description | Published |
20130202803 | ANTIOXIDANT AGENT AND PROCESS FOR PRODUCING METALLIC MATERIAL - There is provided an antioxidant agent excellent in anti-dripping property and anti-peeling property. The antioxidant agent in accordance with the present invention contains a plurality of glass frits having different softening points, potter's clay, and bentonite and/or sepiolite. On account of the potter's clay, the antioxidant agent applied to the surface of a metallic starting material is less liable to drip down. Further, on account of the bentonite and/or sepiolite, the antioxidant agent is less liable to peel off the surface of the metallic starting material. | 08-08-2013 |
20140245806 | METHOD OF PRODUCING SEAMLESS METAL PIPE - A method of producing a seamless metal pipe, which can suppress the occurrence of lamination defects, is provided. A method of producing a seamless metal pipe according to an embodiment of the present invention includes the steps of: heating a high alloy containing, by mass %, Cr: 20 to 30% and Ni: more than 22% and not more than 60% in a first heating furnace (S2); piercing-rolling the high alloy heated in the first heating furnace with a first piercing machine to produce a hollow shell (S3); heating the hollow shell in a second heating furnace (S4); and elongation-rolling the hollow shell heated in the second heating furnace with the first piercing machine or a second piercing machine which is different from the first piercing machine (S5). | 09-04-2014 |
20140250965 | METHOD OF PRODUCING SEAMLESS METAL PIPE - A method of producing a seamless metal pipe, which can suppress the occurrence of inner surface flaws, is provided. A method of producing a seamless metal pipe according to an embodiment of the present invention includes the steps of: heating a high alloy billet BL containing, by mass %, Cr: 20 to 30% and Ni: more than 22% and not more than 60% in a heating furnace F | 09-11-2014 |
20140260494 | PIERCING APPARATUS, PLUG USED FOR PIERCING APPARATUS, AND METHOD FOR PRODUCING SEAMLESS STEEL PIPE - There is provided a piercing apparatus in which the occurrence of an inner surface flaw in a hollow shell is suppressed. A piercing apparatus ( | 09-18-2014 |
20150075243 | PLUG USED IN PIERCING MACHINE - To increase the life of a plug used in a piercing machine for piercing-rolling a billet. The plug ( | 03-19-2015 |