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US 8,024,953 B2Granted
Lubricant for hot working and method for producing seamless steel pipe
AssigneeSumitomo Metal Industries, Ltd.
InventorsKenichi Saito, Sumio Iida
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AssigneeSumitomo Metal Industries, Ltd.
InventorsKenichi Saito, Sumio Iida
Estimating the term…
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.
A method of producing a seamless steel pipe, comprising the steps of:
Dependencies are inferred from the claim text.
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From the US filing history. Foreign family members aren’t listed.
Lubricating compositions containing more than 10% water: not containing mineral or fatty oils
Inorganic compounds or elements as ingredients in lubricant compositions: water
Metal compounds: oxides; Hydroxides; Carbonates or bicarbonates
Compounds containing silicon: silicates
About 2 years 2 months of term left · ends 8 Jan 2029 (estimated)
The present invention relates to a lubricant capable of reducing friction between a workpiece and a hot working tool (hereinafter, referred simply to as a “tool”) and preventing seizing in producing a seamless steel pipe by hot working. More particularly, the invention relates to a lubricant capable of reducing friction between a billet (workpiece) and a guide shoe (tool) and preventing seizing in producing a seamless steel pipe in a piercing-rolling mill. The present invention also relates to a method of producing a seamless steel pipe with the lubricant.
Unless otherwise noted, terms in this description are defined as follows:
“%” represents percent by weight of each component contained in a subject, and
A lubricant of the present invention is prepared by dispersing iron oxide in a mixture of sodium silicate and water (water glass). The iron oxide is preferably in a powder form.
The lubricant of the present invention may contain a stabilizer for stably dispersing iron oxide in addition to the above-described components. The amount of the stabilizer contained is preferably about 20 to 100 grams per 1 liter of lubricant.
In the lubricant of the present invention, impurities are likely to be mixed in the process of preparation. The impurities are exemplified by three kinds of oxides: zinc oxide (ZnO), lead oxide (PbO), and copper oxide (CuO). These three kinds of oxides exert a great influence on the performance of the lubricant of the present invention. Therefore, the upper limit of the amount of impurities in the lubricant of the present invention was defined.