摘要:
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.
摘要:
Provided is a lubricant composition for seamless steel pipes or tubes working which totally satisfies various properties, such as storage stability, transferability inside an apparatus tube, sprayability to lubricated sites, and property of uniform adhesion to a high-temperature mandrel bar without losing non-carburizability or excellent lubricity to hard-to-work materials suchas 13 chromiumsteel and stainless steel. Prepared is a lubricant composition which has a viscosity property represented by the following approximate expression: . Y = a·X b wherein Y: viscosity (mPa·s),x: shear rate (s -1 ) ; and a: 4000 to 40000 and b: -1.0 to -0.3 while the lubricant composition is stored to be kept still, and a: 1000 to 20000, and b: -1.0 to -0.15 after 90 seconds from the time when shearing a lubricant composition is finished.
摘要:
This invention provides a process for producing a seamless pipe while effectively suppressing carburizing which occurs in a seamless pipe without affecting the operation. The production process comprises the steps of cleaning a transfer device disposed between a lubricant coating device (7), which is disposed at least in the step of transferring a mandrel bar (B), and a mandrel mill (8) on its inlet side, cleaning the mandrel bar (B) subjected to stretch rolling on the upstream side of the lubricant coating device (7), and coating a nongraphitic lubricant onto the mandrel bar (B) by the lubricant coating device (7). In the production of the seamless pipe, the transfer device and the mandrel bar (B) are washed so as to satisfy formulae (1): 0.08 × C1 + 0.05 × C2 ≤ 3 and (2): 3 ≤ C1 + C2 ≤ 50 wherein C2 represents the amount of graphite deposited on the surface of the mandrel bar (B) before stretch rolling, g/m2, and C1 represents the content of carbon in an organic binder in the lubricant, g/m2.
摘要:
A process for producing a seamless steel pipe, in which the occurrence of inner surface flaw in the pipe can be reduced through lowering of the friction coefficient at draw rolling by means of a mandrel mill. At the draw rolling of hollow stock pipe, a lubricant composed mainly of at least one of graphite and mica is applied to the surface of mandrel bar, and further a lubricant composed mainly of a borate of monovalent alkali metal is fed onto the inner surface of hollow stock pipe, satisfying the following requirements (a) to (d). (a) The temperature of inner surface of stock pipe immediately after the completion of piercing is set for >= 1150˚C, and the time from the completion of piercing to feeding of the lubricant composed mainly of a borate of monovalent alkali metal, or the time from the completion of descaling to feeding of the lubricant is set for 5 to 60 sec. (b) The temperature of inner surface of stock pipe during the feeding of the lubricant composed mainly of a borate of monovalent alkali metal is set for >= 1100˚C. (c) The time from the feeding of the lubricant composed mainly of a borate of monovalent alkali metal to the initiation of draw rolling is set for >= 10 sec. (d) The temperature of inner surface of stock pipe immediately before the draw rolling is set so as to range from 1000˚ to 1170˚C.
摘要:
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.
摘要:
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.
摘要:
There is provided a lubricant for hot plastic working, which contains 20 to 40 mass% of iron oxide and 10 to 30 mass% of sodium silicate, wherein impurities are 3 mass% or less, and the lubricant contains 40 to 60 mass% of water. By virtue of combined action of these components, the lubricant exhibits excellent lubricity and suppliability and does not adversely affect the corrosion resistance of product. The lubricant is suitably used for lubricating a guide shoe in piercing-rolling, for example, a high-Cr steel and achieves a great effect of preventing a seizure flaw from occurring on the outer surface of product by being applied directly to the outer surface of a workpiece just before piercing rolling, preferably, within one second before starting piercing rolling.
摘要:
A method for the hot working of a Cr-containing steel, which comprises holding a newly formed surface of the Cr-containing steel in a steam atmosphere, to thereby form an oxidized scale containing FeO, and then carrying out a subsequent hot working. More specifically, a method for producing a seamless steal pipe which comprises supplying a moisture to the inside of a raw hollow pipe prepared by piercing, to hold the newly formed inner surface of the raw hollow pipe in a steam atmosphere and thereby form an oxidized scale containing FeO, and then carrying out the subsequent drawing. The method allows, by the use of a simple and easy operation method and a simple device, the reduction of the surface defects being caused after a hot working, resulting in markedly prolonging the life of a tool used therein, which contributes greatly to the efficient production of a Cr-containing steel containing 5 to 18 % of Cr being in increasing demand.