Abstract:
According to the drying method and apparatus of the present invention, at first, the coated film on one end side of the support is more quickly dried than that on the other end side, because drying air is supplied from one end side of the support. Subsequently, the coated film on the other end side of the support is more quickly dried than that on one end side, because drying air is supplied from the other end side of the support. Accordingly, the method and the apparatus can diminish a difference between drying rates in on one end side and in the other end side of the long support, in the whole drying zone. Thus, the method and the apparatus can uniformly dry the support and inhibit the production of a dry spot.
Abstract:
In a drying method of an aspect of the present invention, drying steps are conducted immediately after coating in a drying zone, and during the execution of drying by blowing the one-way flow drying wind flowing from one edge side to another edge side in the width direction of the continuous support, the windless drying step is conducted in a windless drying zone provided in the drying zone where the drying wind is not blown.
Abstract:
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.
Abstract:
An Fe—Ni alloy pipe stock containing, by mass %, C≦0.04%, Si≦0.50%, Mn: 0.01 to 6.0%, P≦0.03%, S≦0.01%, Cr: 20 to 30%, Ni: 30 to 45%, Mo: 0 to 10%, W: 0 to 20%, with Mo(%)+0.5W(%): more than 1.5% to not more than 10%, Cu: 0.01 to 1.5%, Al≦0.01% and N: 0.0005 to 0.20%, and the balance being Fe, with 1440−6000P−100S−2000C≧1300, Ni+10(Mo+0.5W)+100N≦120, (Ni−35)+10(N−0.1)−2(Cr−25)−5(Mo+0.5W−3)+8≧0, can be manufactured into a seamless pipe by use of a Mannesmann piercing and rolling mill because of its excellent inner surface properties. The resulting seamless pipe has excellent mechanical properties and moreover has excellent corrosion resistance in a sour gas environment.
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 (6) 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:
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≦1.2 (2) Lc/Dc≦45 (3)
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 translation:穿孔滚动塞具有由氧化物如Fe 3 O 4和FeO和Fe(金属)构成的膜,其通过使用主要成分为Fe的铁丝通过电弧喷涂形成在母材表面上,并且由于该膜 能够实现优良的隔热防止效果的塞子,延长塞子的使用寿命。 此外,在再生该插头时,可以通过以下步骤重新形成薄膜:依次进行穿孔和滚压以及电弧喷涂中使用的插头的喷丸处理; 因此,可以在低成本和短时间内再生插头。
Abstract:
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 θ1 of the skew rolls, and the square root of the product (Ns×Df)0.5 of the rotational frequency Ns of the billet in a transient (non-steady state) region when billet gripping and the reduction ratio Df of the outer diameter of the billet satisfies a prescribed equation.
Abstract:
The present invention provides a seamless tube piercing/rolling plug and a seamless tube producing method in which piercing/rolling is performed with an inclined rotary piercing mill while the seamless tube piercing/rolling plug is used as a piercing tool. The seamless tube piercing/rolling plug is used while a front part and a rear part of the split plug are held as an integral plug, at least the front part is made of low alloy steel, and oxide films are formed on surfaces of the front part and rear part. The present invention also provides a seamless tube piercing/rolling apparatus and a seamless tube producing method in which the front part and/or rear part is replaceable in a tube making process line using the seamless tube piercing/rolling apparatus. In the seamless tube piercing/rolling apparatus, the front part and rear part are held as the integral plug, the front part and/or rear part is removably mounted, a mandrel bar holding the plug goes through the rear part, and the mandrel bar is coupled with the front part. It is preferable that a thickness of the oxide film formed in the front part be set to 200 μm or more while the oxide film formed in the front part is thicker than the oxide film formed in the rear part. Even if a hard working material is pierced/rolled, a seam defect and inside surface defects are eliminated, and excellent life-time of plug and excellent plug cost per production quantity can be achieved.
Abstract:
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 θ1 of the skew rolls, and the square root of the product (Ns×Df)0.5 of the rotational frequency Ns of the billet in a transient (non-steady state) region when billet gripping and the reduction ratio Df of the outer diameter of the billet satisfies a prescribed equation.