Abstract:
A Cr-plated mandrel bar for manufacturing a hot seamless tube and a method of manufacturing the mandrel bar, the mandrel bar wherein since the maximum depths (Rv) thereof in the axial and circumferential directions are specified together with average centerline roughnesses (Ra) in the axial and circumferential directions and the maximum heights (Rp) in the axial and circumferential directions are limited, seizure and other surface defect is hard to occur on the mandrel bar during the drawing of a mandrel mill to remarkably increase the useful life thereof so as to remarkably reduce tool cost. Also, the mandrel bar can largely contribute to the improvement in quality of the inner surface of the hot seamless tube rolled by the mandrel mill. The method can efficiently manufacture the Cr-plated mandrel bar for manufacturing the hot seamless tube.
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:
agente antiemperramento bicomponente para processo de trabalho de metais a quente, e processo de produção de tubo sem costura usando o mesmo. a presente invenção refere-se a um agente antiemperramento bicomponente para processo de trabalho de metais a quente, compreendendo uma primeira solução aquosa e uma segunda solução aquosa, no qual a primeira solução aquosa contém 10 - 30% em massa de silicato de sódio equivalente a anidrido para 100% em massa da massa total da primeira solução aquosa, e a segunda solução aquosa contém pelo menos um tipo selecionado do grupo consistindo em: um ácido orgânico e sais de amina solúveis em água do mesmo, um ácido inorgânico e sais de amina solúveis em água do mesmo, uma amina solúvel em água, um álcool solúvel em água e um cloreto metálico solúvel em água. quando o agente antiemperramento bicomponente é aplicado nas sapatas de guia do tipo cilindro em forma de disco, o mesmo pode ser proporcionado e mantido na superfície circunferencial das sapatas de guia do tipo cilindro em forma de disco, sem ser lavado pela água de resfriamento dos cilindros. desse modo, o agente antiemperramento não adere aos cilindros e os cilindros e um material de tubo não provocam deslizamento entre eles. desse modo, é possível laminar - mandrilar o material de tubo.
Abstract:
PROBLEM TO BE SOLVED: To obtain a mandrel bar having longer life without generating burning even when the bar is used for rolling high alloy steel containing chromium by forming a chromium plating film in the range of the specific thickness on the mandrel bar. SOLUTION: The chromium plating film of 60-200 μm thick is formed on the surface of a base metal of the mandrel bar. The major cause of generation of burning is peeling of the chromium plating by heat cracks and a lot of burnings are generated in parts where the base metal of the bar is exposed by the elimination of the chromium plating film by wear, so it is necessary to thicken the chromium plating film and, when the thickness is 60-200 μm, the life is rapidly improved. The surface roughness Ra in the direction of the axial length of the base metal is defined as >=0.1 to =2 wt.% Cr in rolling with a mandrel mill, burning is not generated.
Abstract:
PROBLEM TO BE SOLVED: To obtain a two-pack type anti-seizing agent for hot plastic working, in which since an anti-seizing agent applied to a disk roll type guide shoe is not made to flow by cooling water of a roll, the anti-seizing agent is supplied and retained on the peripheral surface of the disk roll type guide shoe, is not adhered to the roll and does not cause a roll slip between the roll and a tubular material and the tubing material is punched and rolled and to provide a method for producing a seamless pipe using the same. SOLUTION: The two-pack type anti-seizing agent comprises a first aqueous solution that contains 10-30% by mass calculated as an anhydride of sodium silicate when the mass of the total of the first aqueous solution is 100% by mass and a second aqueous solution containing one or more kinds selected from the group consisting of an organic acid, its water-soluble amine salt, an inorganic acid, its water-soluble amine salt, a water-soluble amine, a water-soluble alcohol and a water-soluble metal chloride. COPYRIGHT: (C)2006,JPO&NCIPI
Abstract:
PROBLEM TO BE SOLVED: To provide a lubricant for hot plastic working that can prevent the seizure between the material to be processed and the tool as well as inhibits the abrasion and peeling of the plated layer on the tool, and provide a hot plastic working using this lubricant. SOLUTION: This lubricant comprises 50-80 wt.% of an alkali metal borate, 5-30 wt.% of iron oxide, 0-30 wt.% of an alkali metal salt of fatty acid and 0-30 wt.% of an alkali metal sulfate. This lubricant is adhered to the surface to be processed of the material that is heated up to the processing temperature, then the tool is brought into contact with the surface coated with the lubricant to effect the hot plastic working.
Abstract:
PROBLEM TO BE SOLVED: To provide a friction testing method that can simulate damage to a tool used to manufacture a seamless steel pipe and evaluate performance of the tool and a lubricant which are actually used.SOLUTION: There is provided a friction testing method of simulating friction between a tool and a rolled material during manufacture of a seamless steel pipe, the friction testing method including rotating a first columnar test piece 1 and a second columnar test piece 2 on axes 1X, 2X respectively in a state in which the first test piece 1 and the second test piece 2 are held so that the axes 1X, 2X do not intersect while the first test piece 1 and the second test piece 2 are pressed against each other with an outer peripheral surface of the second test piece 2 brought into contact with an end surface of the first test piece 1.
Abstract:
PROBLEM TO BE SOLVED: To provide a plug for piercing a seamless steel tube which has a long life even in rolling of high-allow steel such as stainless steel and a Ni-base alloy and with which a tube excellent in the properties of the inside surface because of small coefficient of friction. SOLUTION: This plug has a covering layer 2a consisting of a columbium base alloy whose Ti-content is 7-45 mass% and compressive deformation resistance at 1,573 K is >=150 MPa on its outside surface. It is better that this covering layer 2a is formed by interposing an intermediate layer made of metal whose specific heat is larger than that of the covering layer.