Abstract: Disclosed are a continuous rolling device and method with interfacial temperature-force controllability for a seamless metal cladding pipe. The device comprises a multi-roller skew rolling mill set, an interfacial temperature-force controlled rolling mill set and a sizing and finishing mill set sequentially distributed along a rolling axis; and the interfacial temperature-force controlled rolling mill set comprises an interface temperature control module and an interface pressure control module sequentially distributed along the rolling axis, the interface pressure control module comprises two racks and a plurality of controlled rolling rollers circumferentially and evenly distributed along the rolling axis, two ends of the controlled rolling roller are respectively mounted on the two racks through corresponding screwdown apparatuses, and the interface pressure control module realizes passive driving through a spiral pushing force or a traction force.

Abstract: The present invention provides a dynamic contact heat transfer simulation device for rolling heavy-load deformation zone. The device includes a control system, a data acquisition system, a pressure-adjustable fixed cold end, a rotating chuck, a temperature-adjustable heat-conducting rod and an speed-adjustable rotation hot end; the device utilizes the rotating chuck and the speed-adjustable rotating hot end to adjust the rotation speed in real time according to the actual rolling conditions, simulate the working conditions of the actual rolling heavy-load deformation zone, and accurately obtain the dynamic heat transfer coefficient of the rotating contact interface under variable load pressure conditions.

Abstract: A ram assembly includes an elongated ram body and a punch mounting assembly. The ram body has a reduced length. The punch mounting assembly includes an elongated body having a complementary length. The punch mounting assembly is coupled to the ram body. The assembled punch mounting assembly and ram body have an operational length.

Abstract: A method for producing a seamless metal pipe includes the steps of: preparing a billet having a diameter (B); heating the billet; forming, in a center part of a rear end of the heated billet, a hole including four grooves extending in an axial direction of the billet, the grooves each having a groove width (D) satisfying Formula (1), a groove height (H) satisfying Formula (2), and a groove depth (L1) satisfying Formula (3); and subjecting the billet provided with the hole to piercing-rolling from a front end thereof by means of a piercing machine. By this means, the generation of burrs and internal defects at the rear end of a hollow shell after piercing-rolling can be suppressed. 0.12?D/B?0.25??(1) 0.10?H/B?0.20??(2) 0.05?L1/B?0.

Abstract: Provided is a method for performing an external pipe thread process on a hollow blank by at least twice rolling: firstly, the first rolling wheel group rolls the outer surface of the hollow blank into a threaded cylindrical surface or a threaded conical surface or a threaded cylindrical conical mixing surface, and secondly, the second rolling wheel group rolls again for the outer surface of the hollow blank which has processed in step 1, and rolling to form an external pipe thread; wherein the number of rolling wheels in a rolling wheel group, used in any two back-to-back rolling processes in a processing sequence, are different in parity. Further provided are various rolling head, module, apparatuses and production line for pipe thread, achieving the above processing method and having a simple structure, portability and practicality.

Abstract: A rolling mill for rolling hollow or, in all cases, concave rod-shaped bodies, in particular tubes, in particular seamless tubes, said rolling mill comprising a rolling section (10) with a plurality of mill stands and/or rolling dies (11) arranged in succession to define a rolling axis Y, said rolling mill further comprising moving means for moving a mandrel (20) and a tubular blank (21) fitted onto an end portion (22) of said mandrel (20) along said rolling axis and through said mill stands or rolling dies (11) in succession; wherein said moving means are structured so as to move said mandrel (20) and said blank (21) along said rolling axis Y and through said mill stands or rolling dies (11) in succession by applying a traction on said mandrel.

Abstract: A method for manufacturing an expansion anchor is provided, in which a bolt is provided, which includes an expansion body for expanding an expansion sleeve surrounding the bolt, an annular sleeve blank having an opening is provided, the bolt is introduced into the opening of the annular sleeve blank, and the annular sleeve blank is reduced in diameter while the bolt is located in the opening of the annular sleeve blank. The invention also relates to expansion anchors, which may be obtained with the aid of the method according to the invention, in particular bolt-type anchors having closed annular expansion sleeves and, in particular, anchors having expansion sleeves with protruding noses, which are each situated on a closing fold of the expansion sleeve.

Abstract: Provided is a method for performing an external pipe thread process on a hollow blank by at least twice rolling, wherein amount of rolling wheels in a rolling wheel set, used in any two back-to-back rolling processes in a processing sequence, are different in parity. Further provided are various roll-processing modules and corresponding rolling apparatuses, achieving the above processing method and having a simple structure, portability and practicality. A hollow blank is not liable to deform when performing an external pipe thread rolling process thereon, thereby improving a processing yield.

Abstract: An integrated transverse rolling mill for rolling seamless tubes with skewed axes comprising a piercing stand (2) with skewed axis rolling rolls for piercing a first tube (7) having a first length which is shorter than the space which separates it from the subsequent finishing stand (3) in cooperation with the stake (6), which has the first piercing tip (20) at its end and the second finishing tip (21) at the finishing stand (3). The finishing stand (3) is arranged downstream of the piercing stand (2) so that during the rolling operations the front end of the first tube (7) may only be gripped by the finishing stand (3) once the rear end of the first tube (7) is no longer gripped by the rolling stand (2).

Abstract: A drawing device for drawing a drawable material, the drawing device comprising at least a pair of tapered rollers each having a taper ratio in a range of 0.035 to 0.50, wherein the taper ratio is represented by (???)/2L, where ? denotes a maximum diameter of the roller, ? denotes a minimum diameter of the roller, and L denotes a length of a tapered portion of the roller.

Abstract: Provided is an equipment system for producing a piercing-rolling plug to be used for producing a seamless steel tube/pipe, which includes a shotblasting device for applying shotblasting on a surface of the plug, and an arc-spraying device for performing arc-spraying of iron wires on a surface of a base metal of the plug to which the shotblasting is applied, so as to form a film containing oxide and Fe thereon. The arc-spraying device includes plural spraying booths each of which separately forms part of the film in turn in each of sections into which the surface of the base metal of the plug is divided along an axial direction of the plug. The production efficiency of the plug can therefore be maintained at a high level, and steady enhancement of the durability life of the plug can be realized during the piercing-rolling.

Abstract: To increase the life of a plug used in a piercing machine for piercing-rolling a billet. The plug (10) is used in a piercing machine (30) that piercing-rolls a billet (36). The plug (10) includes a plug body (12), a build-up layer (14), and a sprayed film (16). The build-up layer (14) is formed on a surface of the plug body (12). The sprayed film (16) covers at least an area ranging from the rear end of the build-up layer (14) to a position of the maximum outer diameter of the plug body (12).

Abstract: By using a piercing mill that includes a pusher on the entrance side, a plug on the exit side along a pass line, and a plurality of angled rolls as being provided around the plug so as face to each other, in the case where the maximum diameter of an unsound region consisting of center segregation and porosity in a cross section of a billet is d [mm], piercing-rolling is performed under the condition that the plug nose rolling reduction ratio (TDF) expressed by Formula (1) satisfies Formula (2). TDF=(Bd?D1)/Bd??(1) TDF??0.50×(d/Bd)+0.06??(2) In Formulae (1) and (2), Bd is the billet diameter [mm], and D1 is the opening [mm] between the angled rolls at the plug nose position. Thereby, when piercing-rolling is performed, the occurrence of an inner surface flaw attributable to the center segregation and porosity in the billet can be prevented reliably.

Abstract: The invention relates to a method for producing seamless tubes from metal, particularly from steel, wherein a previously produced hot hollow block is stretched by means of a three-roll bar rolling mill on a mandrel to form a parent tube and, before running into the bar rolling mill, the hollow block is provided with a rolling step that makes the diameter more uniform by means of an upstream stand. It is in this case provided that the rolls of the upstream stand are moved apart and together to the same extent as the deforming stands of the bar rolling mill, wherein the calibrating base radius of the rolls of the upstream stand extends over 60° and this is followed by a flank radius with a tangential transition which is dimensioned such that even with the maximum setting of the rolls in the region of the flank there is virtually no diameter reduction of the largest hollow block diameter to be expected.

Abstract: It is an objective to provide a plug capable of enhancing a usage count of the plug, which is for use in a piercing machine for piercing-rolling a billet, and a regenerating method of the plug. The plug (10) is for use in a piercing machine (30) for piercing-rolling a billet (36). The plug (10) includes a body (18), a columnar portion (20), and a sprayed film (16). The body (18) has a maximum diameter at its rear end. The columnar portion (20) has the same diameter as the diameter of the rear end of the body (18), and extends from the rear end of the body (18). The sprayed film (16) is formed on a surface of the body (18) and on a surface of the columnar portion (20).

Abstract: 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 TGBm, Psr and P? represented by the following equations (1) to (3) being not more than 1300, not more than 200 and not less than 0, respectively TGBm=1380?5000P?100S?4400C??(1), PsrNi+10(Mo+0.5W)+100N??(2), P?=(Ni?50)+10(N?0.1)?2(Cr?25)?5(Mo+0.5W?6)+12??(3), wherein each element symbol in the equations represents mass % of the element concerned.

Abstract: Provided is a round billet capable of reducing damage on a piercing plug in a method of producing a seamless metal tube with a Mannesmann process. The round billet (5), for use in a seamless metal tube, to be produced into a seamless metal tube with a Mannesmann process includes a body having a hole (6) formed in an axial direction of the body. The hole (6) includes an aperture (6a) opening at least at one end face of the round billet (5), and a tapered portion (61) continued to the aperture (6a) and having a diameter gradually increasing toward the aperture (6a).

Abstract: An apparatus for forging a hollow body from a pre-perforated hollow block includes forging tools that can be driven radially in relation to a forging axis, a clamping head which is displaceable on a guide bed in the direction of the forging axis and includes collet chucks for the hollow block, and a mandrel carriage which is arranged on the side of the clamping head facing away from forging tools, which is displaceable independently of the clamping head along the guide bed, and whose mandrel bar provided with the forging mandrel penetrates the clamping head coaxially to the forging axis. In order to provide advantageous constructional conditions the mandrel carriage includes an axial actuating drive for the mandrel bar and can be coupled in a tension-proof manner to the clamping head.

Abstract: To increase the life of a plug used in a piercing machine for piercing-rolling a billet. The plug (10) is used in a piercing machine (30) that piercing-rolls a billet (36). The plug (10) includes a plug body (12), a build-up layer (14), and a sprayed film (16). The build-up layer (14) is formed on a surface of the plug body (12). The sprayed film (16) covers at least an area ranging from the rear end of the build-up layer (14) to a position of the maximum outer diameter of the plug body (12).

Abstract: The invention relates to a method and a rolling mill for producing a seamless steel pipe in a continuous rolling process, where semi-finished material is first formed into a hollow block (8) in a rotary rolling mill, said block then being rolled in a multi-tooled continuous rolling mill (1) over a previously inserted mandrel (10) to form a tube blank (9), wherein the mandrel (10) receiving the hollow block and held by a mandrel holding and transporting device (5) disposed on the entry side is fed into the continuous rolling mill (1) and is transported back to the entry side after the tube blank has been rolled off of the mandrel (10) on an extracting rolling mill (4) connected downstream of the continuous rolling mill. An aim of the invention is to allow high production rates at the same product quality, particularly at a low drop in the temperature of the tube blanks.

Abstract: 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.

Abstract: 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 F1 (S2); piercing-rolling the high alloy billet BL heated in the heating furnace F1 with a piercing machine P1 to produce a hollow shell (S3); cooling the hollow shell and then reheating the hollow shell in the heating furnace F1 (S4); and elongation-rolling the heated hollow shell with the piercing machine P1 (S5).

Abstract: A rolling mill of rotating expander type for tubular bodies, comprising: working rollers (1, 2) arranged inclined with respect to the rolling axis; a tip (3) fitted on a beam (4), so that the tubular body is pushed in rotation between the rollers and the tip, and subjected to deformation in order to increase the perimeter; a tip-stabilizing system placed behind said tip, about the beam, and integrated in the rolling mill.

Abstract: A method for manufacturing a high alloy pipe comprises hot working, a high alloy material pipe having controlled amounts of C, Si, Mn, P, S, Ni, Cr, Mo, Cu, Al, N, O, and optionally Ca, Mg, and rare earth elements, with the balance Fe. The pipe composition satisfies the formula N×O?0.001. The pipe is subjected to cold working to form the high alloy pipe, wherein the final cold working process is performed under the condition that a working ratio Rd in the reduction of area satisfies 15?Rd (%)?370×(C+N), where N, O and C are the contents (by mass percent) of the respective elements, and Rd is the working ratio (%) in the reduction of area. The pipe has an excellent ductility and an excellent corrosion resistance when cold working is performed to obtain a high strength after pipe-making.

Abstract: An apparatus includes a mandrel having a first end and a second end, the mandrel including a cavity formed therein, a pilot disposed in the cavity formed in the mandrel, a portion of the pilot extending outwardly from the first end of the mandrel, and an insert disposed in a channel formed in the mandrel and through an exterior surface of the mandrel, wherein a portion of the pilot abuts the insert and radial outward movement of the insert is caused by an axial movement of the pilot.

Abstract: A lubricant for hot-rolling tools in which an oxide-based laminar compound such as potassium tetrasilicic mica, sodium tetrasilicic mica, vermiculite, and bentonite, a boric acid compound such as boric acid, potassium borate, and sodium borate, and graphite are dispersed and dissolved in water, and in which the blending proportion of the oxide-based laminar compound to the boric acid compound is, in mass ratio, 10:90 to 70:30, and the content of the graphite is 1.0 to 4.5%. Applying this lubricant on the surface of the mandrel bar at the time of mandrel mill rolling enables a lubricating film to be formed on the surface of the bar and to exert excellent seizure resistance, and also allows the lubricant to be immune from remaining in the inner surface of tube.

Abstract: The present invention is directed to a method for producing a hollow metallic billet (10) from a heated metallic billet (1) by a piercing operation (for example with the use of a piercing mandrel (4)). The method is characterized in that a local temperature change is effected at least at the hole initiation end (11) of the billet (1) in at least one zone (110, 112) and the zone is rotationally symmetrical to the central axis (M) of the billet (1). Also described is a device for producing a hollow metallic billet (10) from a metallic billet (1) and comprising a holder (3) for the billet (1), characterized in that the device includes at least one temperature adjusting device or a projection element (2) operative to change the temperature of the billet (1) in the holder (3) at least zonewise and directed at a subzone of at least one of the end sides of the billet (1).

Abstract: In a method for producing seamless pipes, a hot hollow block created previously in a piercing mill is stretched by means of a continuous rolling mill on a mandrel bar to form a parent pipe and the parent pipe is fed directly to a stretch reducing mill or sizing mill as a finishing mill, while forgoing an extracting mill and a reheating furnace, and is rolled there to the required final pipe diameter. The hollow block is pre-dimensioned in its length in such a manner that only a single length is produced as the required parent pipe length during the stretching in the continuous rolling mill and the parent pipe is pulled off of the mandrel rod by the finishing rolling during the subsequent finishing rolling, wherein the rolling is performed using rolling mill components that are designed in the dimensions thereof for handling single lengths.

Abstract: The invention relates to a hot work tool, in particular a piercing mandrel or a rolling bar for producing seamless pipes or a forging mandrel for hot forging tubular workpieces made of metal, said tool having a main tool body (2), wherein at least one working area of the main tool body (2) is provided with a coating (4). In order to achieve an improved strength of the coating (4) on the main tool body, according to the invention the main tool body (2) has a profiled surface (5) and the coating (4) is applied to the profiled surface (5). The invention further relates to a method for producing such a hot work tool.

Abstract: It is a problem of the present invention to provide a method of manufacturing the seamless pipes having better mechanical properties, by means of a pipe manufacturing method with large energy-saving effect to continuously carry out processes from pierce-rolling to heat treatment. A method of manufacturing a seamless pipe comprising the steps of a pierce-rolling process, elongation rolling process, sizing process, reheating process, quenching process and tempering process, wherein the sizing process is completed with a temperature of the seamless pipe not less than 600° C. but less than 800° C., the seamless pipe is charged into a reheating furnace with a temperature not less than 400° C. and is reheated with a temperature not less than Ac3 transformation temperature but not greater than 1000° C. in the reheating process.

Abstract: 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 TGBm, Psr and P? represented by the following equations (1) to (3) being not more than 1300, not more than 200 and not less than 0, respectively TGBm=1380?5000P?100S?4400C ??(1), PsrNi+10(Mo+0.5W)+100N ??(2), P?=(Ni?50)+10(N?0.1)?2(Cr?25)?5(Mo+0.5W?6)+12 ??(3), wherein each element symbol in the equations represents mass % of the element concerned.

Abstract: A continuously cast slab with a rectangular cross section, and made of high alloy containing Cr of 20 to 30 mass %, Ni of 30 to 50 mass %, and at least one of Mo and W as Mo+0.5W of 1.5 mass % or more is subjected to blooming and billet-making to yield a round bar having a diameter of 150 to 400 mm as a starting material of the seamless tube. The blooming and billet-making process is performed under a condition satisfying a relation of 1.3?H/D?1.8 where a short side length of the cross section of the cast slab is defined as H (mm), and the diameter of the round bar is defined as D (mm). The round bar is pierced-rolled to make a hollow blank; the hollow blank tube is elongation-rolled, and then diameter-adjusting-rolled to make the seamless tube, thereby preventing end cracking during piercing-rolling, and increasing yield.

Abstract: 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.

Abstract: There are provided: a seamless steel pipe formed from a cylindrical steel material billet through a hot isostatic extrusion step, wherein a depth of a contiguous flaw formed on an inner periphery surface and an outer periphery surface of the steel pipe is 50 ?m or less; a hollow spring obtained by forming a hollow body in a shape of a coil or a bar or a bar with curved part from the seamless steel pipe made of spring steel and applying a surface treatment to the hollow body so that the hollow body has compressive residual stress; and a method for producing seamless steel pipe including: a billet molding step; a first heating step; a hot isostatic extrusion step; a second heating step; an extension step; a third heating step; and a pickling step.

Abstract: A production method of a seamless pipe or tube according to the present invention comprises the steps of applying a lubricant containing carbon to a mandrel bar, producing a material pipe or tube with a mandrel mill using the mandrel bar to which the lubricant is applied, and reheating the material pipe or tube in a reheating furnace, wherein when a temperature of the material pipe or tube is 550° C. or higher and 1000° C. or lower in the reheating step, an oxidizing gas is fed into the material pipe or tube.

Abstract: The monitoring apparatus of production conditions in a piercing-rolling mill for piercing and rolling a billet B to produce a pipe S comprises an ultrasonic thickness meter which is installed on an exit side of the piercing-rolling mill and measures a thickness of the pipe S produced by the piercing-rolling mill, a thermometer which is installed on the exit side of the piercing-rolling mill and measures a surface temperature of the pipe S produced by the piercing-rolling mill, and a computing and displaying device which is connected to the ultrasonic thickness meter and the thermometer and displays a thickness distribution in a circumferential direction of the pipe S based on the thickness of the pipe S measured by the ultrasonic thickness meter, and a surface temperature distribution in a circumferential direction of the pipe S based on the surface temperature of the pipe S measured by the thermometer.

Abstract: A plug 2 used for a piercer according to the invention includes a tip end portion 23, a cylindrical portion 24, a barrel portion 25, a mandrel coupling portion 22, and an injection hole 21. The injection hole 21 penetrates from the surface of the cylindrical portion 24 to the surface of the mandrel coupling portion 22 and an externally supplied lubricant is injected from the hole. A clearance forms between the pierced material and the cylindrical portion 24. The injection hole 21 is formed at the cylindrical portion 24, and therefore the material in the process of piercing does not contact the injection hole 21. Therefore, an inner surface defect attributable to the contact between the material and the injection hole 21 can be prevented from being generated.

Abstract: When a hollow billet is inserted into a container, and hot expanding piercing is downwardly performed by using a plug, hot piercing is performed by using a formed glass complex comprising a ring-shaped formed glass part and a ring-shaped projecting part. The ring-shaped formed glass part assumes a disc shape having a circular opening for allowing a plug to be inserted at the center thereof. The ring-shaped projecting part is attached to the opening of the ring-shaped formed glass part, and assumes a ring shape projecting perpendicularly to the ring-shaped formed glass part. Thereby, the piercing work can be done safely, and defects can be prevented from occurring on the inner surface of the billet.

Abstract: The invention relates to an apparatus for making a seamless hollow body (10) from a solid round block (7) of steel with a diameter <95% of the diameter of the solid round block by means of a two-roll cross-rolling mill with a piercing mandrel (3) held between the inclined roll (1) and including a piercer (5) and at least one smoothing part (4) using pass-closing guides, or by means of a three-roll cross rolling mill with a piercing mandrel held between the inclined rolls and including a piercer and at least one smoothing part, wherein the distance of the rolls is adjusted in a particular manner at the narrowest cross-section (2) in relation to the diameter of the used round block, and the position of the piercing mandrel is adjusted in relation to the narrowest cross-section of the rollers.

Abstract: A process for producing seamless pipes which comprises conducting a piercing rolling step, a elongating rolling step using a mandrel bar, and a sizing rolling step and subsequently conducting a product heat treatment. In the process, when the carbon-equivalent weight, namely the sum of the weight of graphite in the lubricant and the carbon content in the organic binder, per unit area of the lubricant adhering to the mandrel bar surface in the above-mentioned step of elongating rolling is expressed by C (g/m2) or the maximum extent of carburization in the inner surface of the pipe to be heat-treated but prior to the heat treatment is expressed by ?C (% by mass), the heating temperature for the pipe to be heat-treated is expressed by T (° C.

Abstract: 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.

Abstract: The present invention relates to a high-lift system of an aircraft having at least one drive unit, having at least one load station as well as having one or more transmissions for transmitting the drive energy of the drive unit to the at least one load station, wherein one or more of the transmission are made as transmission shafts which consist of a material containing titanium or comprise a material containing titanium.

Abstract: 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.

Abstract: The present invention provides a lubricant for hot metal working which is capable of inhibiting generation of white scale, attributed to the lubricant, on the surface of a workpiece material and is capable of improving lubricity to obtain favorable appearance of the finished product. The lubricant for hot metal working comprises a silicate compound used for adding to a lubricant composition mainly containing sodium borate.

Abstract: A piercing and rolling plug has a film composed of oxides such as Fe3O4 and FeO and Fe (metal) as being formed on the surface of the base metal by electric arc spraying using an iron wire whose main component is Fe and, owing to this film, a plug excellent in heat-shielding and seizure-preventing effects can be realized and the lifetime of the plug can be prolonged. Further, in regenerating this plug, a film can be re-formed via the steps of shot blasting of the as-used plug in piercing and rolling and electric arc spraying in that order; thus, it is possible to regenerate the plug at low cost and in a short period of time.

Abstract: The plug is for expanding the inside diameter of the end portion of a metal pipe. Its cross section is a circle, and includes a taper portion and a parallel portion connected to the tail end of the taper portion. The diameter of the taper portion gradually increases from the head end of the taper portion to the tail end of the taper portion where the diameter is D1. The axial distance LR from the point where the diameter D2=D1×0.99 to the tail end where the diameter is D1 satisfies the Expression 22?LR/((D1?D2)/2)?115. The taper angle on the surface where the diameter is D2 is larger than or equal to the taper angle on the tail surface of the taper portion following the point where the diameter is D2. The diameter of the parallel portion is D1.

Abstract: A plug material having a prescribed shape is prepared, the prepared plug material is thermally treated in a heat treatment atmosphere that contains at least 1.0 vol. % oxygen at a heat treatment temperature of at least 950° C. and less than 1050° C. and thus a plug having an oxide scale layer 30 on the surface is manufactured. According to the manufacturing method, pores PO that extend along the surface SF of the plug material are formed under outer scale layer 20 in the oxide scale layer 30, which allows cracks to be more easily propagated in the outer scale layer 20. Therefore, the outer scale layer 20 is more easily peeled off than the conventional one.

Abstract: A pusher device 4 includes a cylinder device 30 and a pusher mandrel 34. The cylinder device 30 includes a cylinder shaft 32. The pusher mandrel 34 is attached to the tip end of the cylinder shaft 32. The tip end of the pusher mandrel 34 is abutted against the rear end of a billet 20. The cross sectional area Sp of the pusher mandrel 34 and the cross sectional area Sb of the billet 20 satisfy Expression (1). The length Lp of the pusher mandrel 34 and the cross sectional area Sp of the pusher mandrel 34 satisfy Expression (2). The moving distance Lc of the tip end of the cylinder shaft 32 during piercing and rolling and the outer diameter Dc of the cylinder shaft 32 satisfy Expression (3). Therefore, the pusher device 4 can restrain the wall thickness deviation of the tip end part of a produced hollow shell. 0.3?Sp/Sb??(1) Lp/Sp?1.

Abstract: A rolling mill of rotating expander type for tubular bodies, comprising: working rollers (1, 2) arranged inclined with respect to the rolling axis; a tip (3) fitted on a beam (4), so that the tubular body is pushed in rotation between the rollers and the tip, and subjected to deformation in order to increase the perimeter; a tip-stabilizing system placed behind said tip, about the beam, and integrated in the rolling mill.

Abstract: A method for manufacturing a seamless pipe, capable of preventing the carburization phenomenon that occurs in a manufacturing process of pipe and simplifying an elongation rolling process, is provided. In this method, after piercing in the piercing rolling process, rolling is performed without using an inside regulating tool in the elongation rolling process, or without performing the elongation rolling followed by reducing rolling in a reducing rolling process, and thickening reducing the wall thickness is then performed by use of a cold mill or cold draw bench in a cold rolling process. According to this method, the trap of graphite fine particles in the inner and outer surfaces of the pipe that took place in the conventional elongation rolling process can be minimized to prevent the carburization of the pipe. The method of the present invention is effective, particularly as a measure for preventing the carburization of an ultra-low carbon stainless steel or high alloy steel.