Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B25/00—Mandrels for metal tube rolling mills, e.g. mandrels of the types used in the methods covered by group B21B17/00; Accessories or auxiliary means therefor ; Construction of, or alloys for, mandrels or plugs
  • B21B25/04—Cooling or lubricating mandrels during operation
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B19/00—Tube-rolling by rollers arranged outside the work and having their axes not perpendicular to the axis of the work
  • B21B19/02—Tube-rolling by rollers arranged outside the work and having their axes not perpendicular to the axis of the work the axes of the rollers being arranged essentially diagonally to the axis of the work, e.g. "cross" tube-rolling ; Diescher mills, Stiefel disc piercers or Stiefel rotary piercers
  • B21B19/04—Rolling basic material of solid, i.e. non-hollow, structure; Piercing, e.g. rotary piercing mills
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M173/00—Lubricating compositions containing more than 10% water
  • C10M173/02—Lubricating compositions containing more than 10% water not containing mineral or fatty oils
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2201/00—Inorganic compounds or elements as ingredients in lubricant compositions
  • C10M2201/087—Boron oxides, acids or salts
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2201/00—Inorganic compounds or elements as ingredients in lubricant compositions
  • C10M2201/087—Boron oxides, acids or salts
  • C10M2201/0873—Boron oxides, acids or salts used as base material
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2201/00—Inorganic compounds or elements as ingredients in lubricant compositions
  • C10M2201/10—Compounds containing silicon
  • C10M2201/102—Silicates
  • C10M2201/103—Clays; Mica; Zeolites
  • C10M2201/1033—Clays; Mica; Zeolites used as base material
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2040/00—Specified use or application for which the lubricating composition is intended
  • C10N2040/20—Metal working
  • C10N2040/241—Manufacturing joint-less pipes
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2040/00—Specified use or application for which the lubricating composition is intended
  • C10N2040/20—Metal working
  • C10N2040/244—Metal working of specific metals
  • C10N2040/247—Stainless steel
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2050/00—Form in which the lubricant is applied to the material being lubricated
  • C10N2050/015—Dispersions of solid lubricants
  • C10N2050/02—Dispersions of solid lubricants dissolved or suspended in a carrier which subsequently evaporates to leave a lubricant coating

Definitions

• the present invention relates to a method of manufacturing a seamless steel pipe by the Mannesmann pipe manufacturing method, and in particular, to efficiently manufacture a seamless steel pipe by improving the life of a plug used without reducing efficiency during piercing and rolling.
• the present invention relates to a method for manufacturing a seamless steel pipe.
• the seamless steel pipe can be manufactured by the Mannesmann pipe manufacturing method.
• This pipe making process consists of the following steps: (1) A round billet heated to a predetermined temperature is pierced and rolled by a piercing machine (piercer) and formed into a hollow shell (hollow shell); (2) The hollow shell is stretch-rolled by a stretching mill (eg, mandrel mill); (3) Using a constant diameter rolling mill (eg, stretch reducer), the stretched hollow shell is constant-rolled to a predetermined outer diameter and thickness.
• a stretching mill eg, mandrel mill
• a constant diameter rolling mill eg, stretch reducer
• a plug In piercing and rolling with a piercing machine, a plug is used as a piercing tool. This plug is attached to the end of the cored bar, and in this state, a billet heated to a high temperature of about 1200 ° C. is perforated, so that it is exposed to a severe situation in which high surface pressure is applied with high heat.
• a plug uses hot tool steel as a base material, and in order to protect the base material, an oxide scale film is previously formed on the surface of the base material by heat treatment, and then used for piercing and rolling.
• the scale film on the plug surface serves as a protective film that blocks heat transfer from the billet to the plug base material and prevents seizure between the billet and the plug.
• the scale film on the plug surface gradually wears with repeated use for piercing and rolling.
• the heat shielding effect by the coating is reduced, so that the temperature of the plug rises during drilling, and the plug base material is easily melted and thermally deformed.
• seizure occurs and wrinkles are generated on the inner surface of the steel pipe. For this reason, the plug is rendered unusable when the scale film is lost and reaches the end of its life.
• Patent Document 1 discloses a technique that employs a water glass-based aqueous solution as a lubricant and regulates the application conditions of the water glass-based aqueous solution to the scale film on the plug surface. Specifically, when the plug is cooled after piercing and rolling and subsequently used repeatedly for piercing and rolling, the plug is cooled when the surface temperature of the plug is 150 ° C. or lower and a temperature portion of 100 ° C. or higher exists in the plug. After interrupting and evaporating the water film on the plug surface, a water glass aqueous solution is applied to the plug surface to form a water glass lubricant coating film.
• Patent Document 2 employs a scale melting material such as a boric acid oxide represented by B 2 O 3 as a lubricant, and performs piercing and rolling by applying the scale melting material to the scale film on the plug surface. Is disclosed.
• a scale melting material such as a boric acid oxide represented by B 2 O 3 as a lubricant
• Patent Document 2 rather than improving the plug life, the purpose is to prevent the occurrence of flaws on the inner surface of the steel pipe, and a boric acid-based oxide or the like is simply selected as a lubricant applied to the scale film.
• a boric acid-based oxide or the like is simply selected as a lubricant applied to the scale film.
• the technique disclosed in Patent Document 2 has room for improvement in that the plug life is surely improved without reducing the efficiency of piercing and rolling.
• Patent Document 3 as a protective film formed on the surface of the plug base material, instead of a scale film by heat treatment, a film composed of oxide and Fe is formed by arc spraying an iron wire material on the surface of the plug base material.
• a technique for forming and performing piercing and rolling using a plug with an arc spray coating is disclosed.
• the document describes that a lubricant such as boric acid (H 3 BO 3 ) may be applied and laminated on the arc sprayed coating formed on the plug surface.
• a plug with an arc sprayed coating has a thermal barrier and anti-seizure property because the protective coating on the plug surface is composed of oxide and Fe, and can improve the life of the plug. It can be expected to increase.
• Patent Document 3 merely selects boric acid or the like as the lubricant applied to the arc sprayed coating, and does not pay any attention to the specific composition and application conditions of the lubricant. . For this reason, the technique disclosed in Patent Document 3 also has room for improvement in terms of reliably realizing an improvement in the plug life without reducing the efficiency of piercing and rolling.
• the present invention has been made in view of the above circumstances, and its purpose is to provide a method for producing a seamless steel pipe having the following characteristics, focusing on piercing and rolling: (1) to reliably improve the life of the plug for piercing and rolling without lowering the efficiency of piercing and rolling; (2) To increase the production efficiency of seamless steel pipes.
• the gist of the present invention is as follows.
• the method of manufacturing the seamless steel pipe is as follows: Applying a lubricant in an aqueous solution containing a total of 5 to 30% by mass of one or more of boron oxide, boric acid and boric acid amine salt to the protective film of the plug, and using the plug for piercing and rolling. , A method for producing a seamless steel pipe characterized by the above.
• the protective film is formed by arc spraying an iron wire on the surface of the plug base material, and is composed of oxide and Fe.
• the method for producing a seamless steel pipe of the present invention has the following remarkable effects: (1) By applying a lubricant to the protective film formed on the surface of the plug for piercing and rolling under appropriate conditions, the plug life can be reliably improved without reducing the efficiency of piercing and rolling; (2) It is possible to manufacture seamless steel pipes efficiently with securing efficiency of piercing and rolling and improving plug life.
• the present inventors presuppose that a protective film is formed on the surface of a base material of a plug for piercing and rolling, and a lubricant is applied to the protective film and laminated to be used for piercing and rolling. , Earnestly studied. Then, as shown in the examples described later, piercing and rolling is performed using plugs with various types of lubricants, component compositions and application conditions, and types of protective coatings, and the plug life is evaluated together with the efficiency of piercing and rolling. As a result of the test, the following findings were obtained.
• boric acid aqueous solution By using a boric acid aqueous solution, the drilling efficiency is greatly improved and the plug life is reliably improved.
• the drilling efficiency here is defined as follows.
• the billet is conveyed along the pass line while being rotated by a plurality of rotating rolls (piercer rolls) installed around the pass line.
• the speed at which the billet is conveyed (hereinafter referred to as “conveying speed”) is determined by the number of rotations of the piercer roll. For this reason, it becomes slower than the theoretical transport speed calculated from the set rotation speed of the piercer roll.
• the manufacturing method of the seamless steel pipe of the present invention has been completed based on the above knowledge. Below, the reason and the preferable aspect which prescribed
• the plug used for piercing and rolling in the present invention has a protective film formed on the surface of a base material, and a boric acid aqueous solution (lubricant) having a component composition described later is applied to the protective film and laminated. It is.
• the protective coating may be a scale coating formed by heat treatment, or an arc sprayed coating formed of oxide and Fe formed by arc spraying of an iron wire. This is because, in any protective film, by applying a boric acid aqueous solution having an appropriate component composition described later as a lubricant, the drilling efficiency can be greatly improved and the plug life can be stably improved.
• the plug life is dramatically improved compared to the case of scale coating.
• the arc sprayed coating has a higher reactivity with the boric acid-based binder contained in the boric acid-based aqueous solution than the scale coating, and significantly brings about the effect of smoothing the plug surface.
• the lubricant employed in the present invention is a boric acid aqueous solution lubricant in which an oxide layered material such as mica or talc is dispersed in a solvent (water) together with a boric acid binder.
• This lubricant can contain a dispersing agent such as a water-soluble polymer in order to stably disperse the oxide-based layered substance and the boric acid-based binder.
• “%” of the component content means “mass%”.
• the boric acid-based binder causes the oxide-based layered substance in the lubricant to adhere to the surface to be lubricated (protective coating on the plug surface) during application, and also melts itself during piercing and rolling to rub the oxide-based layered substance. In addition to smooth supply to the surface to be lubricated, it reacts with the protective coating to smooth the plug surface and reduce frictional resistance.
• boric acid binder one or more of boron oxide, boric acid, and boric acid amine salt can be selected.
• the binder itself is excessive and precipitates, making it difficult to apply the lubricant.
• the content is less than 5%, the amount of melting of the binder itself is insufficient at the time of piercing and rolling, and accordingly, the supply of the oxide-based layered material to the surface to be lubricated becomes insufficient. For this reason, in any case, the frictional resistance is not sufficiently lowered, the drilling efficiency is deteriorated, and satisfactory lubrication performance cannot be obtained. Therefore, the total content of boric acid binder in the lubricant is in the range of 5 to 30%. A more desirable range is 5 to 25%.
• the content of the oxide-based layered substance is not particularly limited. However, too much content causes aggregation of the oxide-based layered material, making it difficult to apply the lubricant. On the other hand, too little content causes insufficient supply of the oxide-based layered material to the lubricated surface during piercing rolling. Thus, a sufficient reduction effect of frictional resistance cannot be obtained. Therefore, the content of the oxide-based layered material is preferably in the range of 10 to 40% when the boric acid-based binder is included in the above range.
• the content of the dispersant is not particularly limited. However, too much content only deteriorates the cost, and if it is too little, the effect cannot be obtained. Therefore, when a dispersant is contained, the content is preferably in the range of 0.11 to 3.0%.
• the method for applying the lubricant having such a component composition to the protective film on the plug surface is not limited.
• the lubricant can be applied directly with a brush or the like.
• a desirable method is a spray method in which a lubricant is sprayed using a nozzle. This is because work efficiency is good and uniform application is possible.
• the surface temperature of the plug tip exceeds 100 ° C. when applying a lubricant of boric acid aqueous solution, the moisture in the lubricant evaporates into bubbles, so that the lubricant for the protective film (oxide type) Adhesiveness of the layered substance and boric acid binder) is impaired. As a result, at the time of piercing and rolling, with the heat input from the billet to the plug, the plug becomes high temperature and the plug tip portion is melted.
• the lower limit of the plug tip surface temperature at the time of applying the lubricant is not particularly limited, but if the plug is cooled to less than 30 ° C., the cooling time increases and the efficiency of piercing and rolling decreases, which is economically disadvantageous. . For this reason, it is preferable that the plug tip surface temperature at the time of lubricant application is 30 ° C. or higher.
• the method for cooling the plug after such piercing and rolling is not limited.
• the plug after piercing and rolling can be immersed in a water tank, or the plug after piercing and rolling can be cooled with water.
• the plug life during piercing and rolling can be stably improved without reducing the efficiency of piercing and rolling, and the efficiency of the entire manufacturing process of seamless steel pipe can be increased. It becomes possible.
• Example 1 The test conditions of Example 1 are as follows.
• Plug and lubricant A plurality of plugs having a scale film formed over the entire surface of the base material by heat treatment were prepared. As shown in Table 1 below, various types of boric acid aqueous solutions in which the types and contents of boric acid binders (boron oxide, boric acid, and boric acid amine salts) were changed were prepared as lubricants, and these lubricants were plugged. It was applied to the scale film on the surface, dried and laminated. In addition to the boric acid binder, these boric acid based aqueous lubricants contain 10 to 40% of mica as the oxide layered material and one or more water-soluble polymers as the dispersant in total. 11 to 3.0% was contained.
• boric acid based aqueous lubricants contain 10 to 40% of mica as the oxide layered material and one or more water-soluble polymers as the dispersant in total. 11 to 3.0% was contained.
• a plug in which a water glass aqueous solution was applied as a lubricant to the scale film on the plug surface and dried and laminated, and a plug having only the scale film without applying the lubricant were also prepared.
• Test results shown in Table 1 indicate the following. Test numbers 1, 2, 4 to 9 all satisfy the conditions defined in the present invention. Therefore, the drilling efficiency exceeded 75% in any of test numbers 1, 2, 4 to 9. In addition, in test numbers 1, 2, 4 to 8 of these, no seizure or peeling of the film occurred on the plug surface, and the surface properties were good. However, the test number 9 is that the content of the boric acid binder in the lubricant applied to the scale film is 30%, which is the upper limit of the specified amount of the present invention. Minor seizure occurred with no problem.
• Test No. 3 had a boric acid binder content of 2.5% in the lubricant, which was less than the specified amount of the present invention, so the drilling efficiency did not reach 75%.
• the content of the boric acid binder in the lubricant was 35%, which was larger than the prescribed amount of the present invention, so that the perforation efficiency did not reach 75% and seizure occurred on the plug surface.
• Test No. 11 employs a water glass-based aqueous solution as a lubricant to be applied to the scale film, and does not satisfy the specified conditions of the present invention. Therefore, the drilling efficiency exceeded 75%, but the film peeled off on the plug surface. Repeated use became impossible. In Test No. 12, since no lubricant was applied to the scale film and the prescribed conditions of the present invention were not satisfied, the drilling efficiency did not reach 75%, and seizure occurred on the plug surface.
• Example 2 The test conditions of Example 2 are as follows.
• Plug and lubricant A plurality of plugs having a scale film formed over the entire surface of the base material by heat treatment were prepared. In addition to this, a plurality of plugs were prepared in which an arc sprayed coating composed of oxide and Fe was formed by arc spraying of iron wire over the entire surface of the base material.
• a boric acid aqueous solution containing an oxide layered material and a dispersant as in the lubricant used in Example 1 and containing 15% boric acid binder of boric acid amine salt was prepared.
• a protective coating scale coating, arc spray coating
• the plug was cooled after the piercing and rolling, and the surface temperature of the plug tip when applying the lubricant was variously changed. This temperature change was performed by adjusting the cooling time of the plug.
• the plug life is the number of passes when the film peels off and the plug cannot be used, or when the plug tip is melted or deformed, that is, the number of billets that can be continuously pierced and rolled (continuous piercing). Frequency).
• the plug life was evaluated based on the plug life when the plug tip surface temperature when the lubricant was applied exceeded 100 ° C. Table 2 also shows the survey results and the evaluation results.
• Test results 21 to 28 are when a scale film is used as the protective film
• test numbers 31 to 38 are when an arc sprayed film is used as the protective film.
• test numbers 21 to 26 all had a plug tip surface temperature of 100 ° C. or less when the lubricant was applied. Improved about twice.
• test numbers 31 to 36 all had a plug tip surface temperature of 100 ° C. or less when the lubricant was applied. The plug life has improved by about 3 times.
• the present invention can be effectively used for the production of seamless steel pipes by the Mannesmann pipe manufacturing method.
• seamless steel pipes made of high alloy steels such as high Cr steels containing 9% or more of Cr, Ni-base alloys and stainless steels are used. Useful when manufacturing.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Organic Chemistry (AREA)
• Lubricants (AREA)
• Laminated Bodies (AREA)
• Other Surface Treatments For Metallic Materials (AREA)
• Coating By Spraying Or Casting (AREA)

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• 2010
  • 2010-12-22 JP JP2010285670A patent/JP5142232B2/ja active Active
• 2011
  • 2011-12-20 WO PCT/JP2011/007092 patent/WO2012086177A1/ja active Application Filing
  • 2011-12-20 EP EP11850562.7A patent/EP2656935B1/en active Active
  • 2011-12-20 BR BR112013013743A patent/BR112013013743B8/pt active IP Right Grant
  • 2011-12-20 CN CN201180062206.1A patent/CN103269809B/zh active Active
  • 2011-12-20 US US13/996,128 patent/US20130269407A1/en not_active Abandoned
  • 2011-12-20 MX MX2013006659A patent/MX345492B/es active IP Right Grant

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