US20110023570A1 - Method for Producing High-Alloy Seamless Steel Pipe - Google Patents

Method for Producing High-Alloy Seamless Steel Pipe Download PDF

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Publication number
US20110023570A1
US20110023570A1 US12/887,100 US88710010A US2011023570A1 US 20110023570 A1 US20110023570 A1 US 20110023570A1 US 88710010 A US88710010 A US 88710010A US 2011023570 A1 US2011023570 A1 US 2011023570A1
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US
United States
Prior art keywords
piercing
seamless steel
steel pipe
producing
main rolls
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US12/887,100
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English (en)
Inventor
Kenichi Saitou
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nippon Steel Corp
Original Assignee
Sumitomo Metal Industries Ltd
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Filing date
Publication date
Application filed by Sumitomo Metal Industries Ltd filed Critical Sumitomo Metal Industries Ltd
Assigned to SUMITOMO METAL INDUSTRIES, LTD. reassignment SUMITOMO METAL INDUSTRIES, LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: SAITOU, KENICHI
Publication of US20110023570A1 publication Critical patent/US20110023570A1/en
Abandoned legal-status Critical Current

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Classifications

    • 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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B27/00—Rolls, roll alloys or roll fabrication; Lubricating, cooling or heating rolls while in use
    • B21B27/06—Lubricating, cooling or heating rolls
    • B21B27/10—Lubricating, cooling or heating rolls externally
    • B21B2027/103—Lubricating, cooling or heating rolls externally cooling externally
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B2267/00—Roll parameters
    • B21B2267/10—Roughness of roll surface
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B23/00—Tube-rolling not restricted to methods provided for in only one of groups B21B17/00, B21B19/00, B21B21/00, e.g. combined processes planetary tube rolling, auxiliary arrangements, e.g. lubricating, special tube blanks, continuous casting combined with tube rolling
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B27/00—Rolls, roll alloys or roll fabrication; Lubricating, cooling or heating rolls while in use
    • B21B27/02—Shape or construction of rolls
    • B21B27/024—Rolls for bars, rods, rounds, tubes, wire or the like
    • B21B27/025—Skew rolls
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B45/00—Devices for surface or other treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills
    • B21B45/004—Heating the product

Definitions

  • the present invention relates to a method for producing a high-alloy seamless steel pipe, in particular, a method for producing a high-alloy seamless steel pipe free from occurrence of outer surface flaws.
  • Mannesmann pilger mill process the Mannesmann plug mill process and the Mannesmann mandrel mill process are known as the methods for producing a seamless steel pipe.
  • Mannesmann mandrel mill process in which a hollow blank is obtained by piercing a heated billet with a piercing mill and then the obtained hollow blank having a mandrel bar inserted thereinto is rolled with a mandrel mill.
  • Patent Document 1 discloses an invention in which piercing is conducted in such a way that when a martensite stainless slab containing, by mass percent, Cr: 10.0 to 16.0% and Ni: 1.0 to 8.0% is heated, the lower layer of the oxide scales produced on the surface of the slab contains metal pieces, and has an area ratio of the voids to the whole cross section set at 20% or less and an thickness set at 150 ⁇ m or less.
  • Patent Document 2 discloses a method for producing a seamless pipe formed of a hardly-workable exterior-scraped stock containing 4.5 mass % or more by means of an inclined roll piercing method. This method uses a stock in which the maximum value of the difference between the maximum step height and the minimum step height in a length of 25 mm in the longitudinal direction of the stock is measured at ten different arbitrary points, and an average value (ten-point average step height) of the thus obtained ten values is 2.0 mm or less.
  • Patent Documents 1 and 2 each describe a technique for reducing the outer surface flaws by regulating the stock itself subjected to piercing-rolling.
  • Patent Document 3 describes a technique for reducing the outer surface flaws by regulating the shape of the main rolls in piercing-rolling. This technique is associated with a method for obtaining a seamless metal pipe; a workpiece is being spirally moved and piercing-rolled in the method. A pair of cone-shaped main rolls and a pair of disk rolls disposed alternately around the pass line of the workpiece. A plug is disposed along the pass line and is disposed between the main rolls and the disk rolls. In this method, the disk rolls are inclined at skew angle ⁇ from the pass line so as to non-parallel with the exit-side face angles of the main rolls.
  • the above-described skew angle ⁇ is set in such a way that the relation “ ⁇ 2 +2° ⁇ 9°” ( ⁇ 2 : the exit-side face angle of each of the main rolls) and the relation “ ⁇ + ⁇ 1 ⁇ 12°” ( ⁇ 1 : the entrance-side face angle of each of the main rolls) are satisfied, and the pipe expansion ratio is set at 1.15 or more. In this way, the occurrence of the outer surface flaws is prevented.
  • Patent Document 4 describes a technique for preventing the occurrence of the outer surface flaws in piercing-rolling by using disk guide rolls which made of a low-alloy steel composed of 0.2 to 0.5% by weight of C, 0.5 to 4% by weight of Cr, 0.5 to 4% by weight of Ni and the balance being Fe and unavoidable elements and have a 50 to 500 ⁇ m heat treated scale in the surface layer thereof.
  • Patent Document 5 discloses a technique associated with a guide shoe used in inclined piercing or inclined rolling of a seamless steel pipe.
  • a guide shoe is divided into two parts, i.e. the main part and the bottom part, in the thickness direction thereof.
  • a plurality of spherical tools constituted with a ceramic or a cermet material are interposed between the main part and the bottom part.
  • the spherical tools are partially made to project from small holes on the guide shoe surface, wherein the small holes are smaller in diameter than the spherical tools; and thus the occurrence of the outer surface flaws is prevented.
  • Patent Document 1 JP2001-96304A
  • Patent Document 2 JP2003-53403A
  • Patent Document 3 JP7-124612A
  • Patent Document 4 JP6-262219A
  • Patent Document 5 JP11-285709A
  • the prior arts disclose the techniques for preventing outer surface flaws of seamless steel pipes on the basis of the methods involving the regulation of the surface conditions of the workpiece, the shape modification of the main rolls in piercing-rolling, the surface treatment of the guide shoe, the material regulation of the disk guide rolls and the like; however, none of the conventional techniques pays attention to the surface roughness of the main rolls.
  • the present invention is achieved for solving the above-described problems, and the object of the invention is to provide a method for producing a high-alloy seamless steel pipe free from occurrence of outer surface flaws.
  • FIG. 1 is a view illustrating the occurrence condition of pipe-swelling in a high-alloy seamless steel pipe.
  • a workpiece 4 is pierced with a plug 1 and is rolled with main rolls 2 and guide rolls 3 while the outer diameter of the workpiece 4 is being controlled.
  • the pipe-swelling occurs on the location indicated by B in FIG. 1 at the time of piercing-rolling, the pipe-swelling develops into outer surface flaws.
  • the present inventor has discovered that there is a correlation between a pipe-swelling ratio and the outer surface flaws, wherein the pipe-swelling ratio defined as “the outer diameter of the pipe-swelling portion of a workpiece/the gap of the main rolls”.
  • the pipe-swelling ratio represent that the fin flaw conditions tends to develop into outer surface flaws of a high-alloy seamless steel pipe.
  • a study performed by the present inventor has revealed that when the pipe-swelling ratio is regulated to be less than 1.10, the outer surface flaws of a seamless steel pipe can be dramatically reduced.
  • the outer diameter of the fin flaw portion of a workpiece means the length indicated by A in FIG. 1
  • the gap of the main rolls means the length indicated by W R in FIG. 1 .
  • the present inventor examined in detail the effects of the various piercing-rolling conditions on the pipe-swelling ratio. Then, the present inventor consequently has discovered that the effect of the surface roughness R max of the main rolls of a piercing mill is most significant, and others such as the following also affect the pipe-swelling ratio:
  • W G is a ratio (W G /W R ), wherein W R is a gap of a main rolls of the piercing mill, and W G is a gap of a guide rolls of the piercing mill;
  • ⁇ P ⁇ R a difference between an exit-side face of each of the main rolls of the piercing mill and the pass line
  • ⁇ P is an angle between a rolling face of the piercing plug and the pass line
  • the present invention has been achieved on the basis of the above-described findings, and the present invention involves a method for producing a high-alloy seamless steel pipe shown in the following (1) to (6).
  • a method for producing a high-alloy seamless steel pipe including steps of:
  • a ratio (W G /W R ) is set at 1.10 to 1.20 in the piercing-rolling process, where W R is the gap of the main rolls of the piercing mill; and W G is the gap of the guide rolls of the piercing mill.
  • surface temperature of a workpiece during the piercing-rolling process is set at 900 to 1250° C.
  • a difference ( ⁇ P ⁇ R ) is set at 0 to 3.0°, wherein ⁇ R is an angle between an exit-side face of each of the main rolls of the piercing mill and the pass line; and ⁇ P is an angle between a rolling face of the piercing plug and the pass line.
  • a flow rate of a roll-cooling water at the time of piercing the seamless steel pipes of ordinary steel is set at 1000 to 1500 l/min.
  • the pipe-swelling occurring at the time of piercing a high-alloy seamless steel pipe can be prevented and hence the occurrence of the outer surface flaws of the seamless steel pipe can be prevented.
  • FIG. 1 is a view illustrating the occurrence condition of pipe-swelling in a high-alloy seamless steel pipe
  • FIG. 2 is a view illustrating an angle between a main roll and a pass line and an angle between a plug and the pass line;
  • FIG. 3 is a graph showing a relation between the surface roughness of the main rolls and a pipe-swelling ratio in an Example
  • FIG. 4 is a graph showing a relation between the number of rolled billets of ordinary steel and the surface roughness of the main rolls in another Example;
  • FIG. 5 is a graph showing a relation between a ratio (W G /W R ) and the pipe-swelling ratio in yet another Example.
  • FIG. 6 is a graph showing a relation between a difference ( ⁇ P ⁇ R ) and the pipe-swelling ratio in still yet another Example.
  • a billet heated with a heating furnace is pierced with a piercing mill to yield a hollow blank; the hollow blank was subjected to elongation rolling with a mandrel mill or the like, and where necessary, further subjected to sizing with a sizing mill or the like to produce a high-alloy seamless steel pipe.
  • a surface roughness R max of main rolls used in the piercing-rolling process have regulated to fall within a range from 150 to 500 ⁇ m.
  • the surface roughness R max of the main rolls is as extremely flat as less than 150 ⁇ m, the gripping force of the rolls at the time of piercing is insufficient and the pipe-swelling of the workpiece come to be remarkable.
  • the surface roughness R max of the main rolls exceeds 500 ⁇ m, flaws due to the rolls occur on the workpiece. Therefore, in the piercing-rolling process in the present invention, the surface roughness R max of the main rolls is set at 150 to 500 ⁇ m.
  • the main rolls that meet the above-described surface roughness range it is recommended to use the main rolls that have been used for piercing seamless ordinary steel pipes.
  • the number of the times of rolling the ordinary steel is not restricted, but it is preferably to use the rolls that have been used for rolling of approximately 3000 to 4000 billets.
  • the flow rate of the roll-cooling water at the time of piercing seamless ordinary steel pipes is about 2000 to 2500 l/min; it is recommended to set the flow rate at 1000 to 1500 l/min. In this way, it is possible to reduce the number of the rolled billets required for regulating the roll surface roughness so as to fall within the above-described range.
  • the piercing is preferably performed in such a way that the ratio (W G /W R ) falls within a range from 1.10 to 1.20, wherein W R is the gap of the main rolls of the piercing mill; and W G is the gap of the guide rolls of the piercing mill.
  • W R is the gap of the main rolls of the piercing mill
  • W G is the gap of the guide rolls of the piercing mill.
  • the surface temperature of a workpiece at the time of piercing preferably falls within a range from 900 to 1250° C. This is because there is a possibility that when the piercing temperature is lower than 900° C., the deformation resistance of the workpiece subjected to the piercing-rolling is increased to cause the occurrence of pipe-swelling, and when the piercing temperature exceeds 1250° C., the workpiece is melted to cause the occurrence of internal flaws.
  • the piercing is preferably performed in such a way that the difference ( ⁇ P ⁇ R ) falls within a range from 0 to 3.0°.
  • ⁇ R is an angle between the exit-side face of each of the main rolls of the piercing mill and the pass line and ⁇ P is an angle between the rolling face of the piercing plug and the pass line.
  • ⁇ P is an angle between the rolling face of the piercing plug and the pass line.
  • the angle ⁇ R and the angle ⁇ P are labeled as ⁇ R and ⁇ P in FIG. 2 , respectively.
  • a billet of 225 mm in outer diameter and 3,000 mm in length was obtained by casting a 13%-Cr steel (SUS 403), the billet was heated to 1200° C. Then the billet was subjected to piercing by using various main rolls (the roll diameters were 1,200 mm) different in the surface roughness R max . Pierced shells of 228 mm in outer diameter and 18.75 mm in wall thickness were produced. The surface roughness of each of the main rolls was regulated on the basis of the number of the billets of ordinary steel (S25C) subjected to the beforehand-performed rolling. The results are shown in FIG. 3 .
  • the pipe-swelling ratio (the outer diameter of the fin flaw portion of the workpiece/the gap of the main rolls) exceeded 1.15. Outer surface flaws tend to occur in this condition. However, with the increase of the surface roughness R max of the main rolls, the pipe-swelling ratio decreased, and when the surface roughness R max of the main rolls was 150 ⁇ m or more, the pipe-swelling ratio was found to be 1.10 or less.
  • the surface roughness R max of the main rolls increased.
  • the surface roughness R max of the main rolls was able to be 150 ⁇ m or more.
  • the cooling water flow rate was set at approximately 2500 l/min in the usual cases (examples represented by ⁇ in FIG. 4 ), and the cooling water flow rate was set at 1500 l/min in the water-reduced cases (examples represented by ⁇ in FIG. 4 ).
  • W G is the gap of the main rolls of the piercing mill
  • W G is the gap of the guide rolls of the piercing mill.
  • the main rolls having a surface roughness R max of 175 ⁇ m regulated by rolling ordinary steel were used, the ratio (W G /W R ) were regulated to be various values, and the above-described 13%-Cr steel experiment was subjected to piercing-rolling.
  • Other conditions were the same as the conditions in above-described Example 1. The results are shown in FIG. 5 . As shown in FIG.
  • the present inventor investigated the relation between the difference ( ⁇ P ⁇ R ) and the pipe-swelling ratio, wherein ⁇ R is an angle between an exit-side face of each of the main rolls of the piercing mill and the pass line; and Op is an angle between a rolling face of the piercing plug and the pass line.
  • ⁇ R is an angle between an exit-side face of each of the main rolls of the piercing mill and the pass line
  • Op is an angle between a rolling face of the piercing plug and the pass line.
  • main rolls having surface roughness R max of 175 ⁇ m regulated by rolling ordinary steel were used, the ratio (W G /W R ) was regulated to be 1.15, the difference ( ⁇ P ⁇ R ) was regulated to be various values, and the above-described 13%-Cr steel was subjected to piercing-rolling.
  • Other conditions were the same as the conditions in above-described Example 1. The results are shown in FIG. 6 .
  • the present invention it is possible to prevent the pipe-swelling occurring at the time of piercing a high-alloy seamless steel pipe, and hence it is possible to prevent the occurrence of the outer surface flaws of the seamless steel pipe.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Reduction Rolling/Reduction Stand/Operation Of Reduction Machine (AREA)
  • Extrusion Of Metal (AREA)
US12/887,100 2008-03-28 2010-09-21 Method for Producing High-Alloy Seamless Steel Pipe Abandoned US20110023570A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP2008-087150 2008-03-28
JP2008087150A JP4371247B2 (ja) 2008-03-28 2008-03-28 高合金継目無鋼管の製造方法
PCT/JP2008/072006 WO2009118957A1 (ja) 2008-03-28 2008-12-04 高合金継目無鋼管の製造方法

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PCT/JP2008/072006 Continuation WO2009118957A1 (ja) 2008-03-28 2008-12-04 高合金継目無鋼管の製造方法

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US12/887,100 Abandoned US20110023570A1 (en) 2008-03-28 2010-09-21 Method for Producing High-Alloy Seamless Steel Pipe

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US (1) US20110023570A1 (pt)
EP (1) EP2286934B1 (pt)
JP (1) JP4371247B2 (pt)
CN (1) CN101980801B (pt)
BR (1) BRPI0822466B1 (pt)
MX (1) MX2010010438A (pt)
WO (1) WO2009118957A1 (pt)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104588411A (zh) * 2015-01-26 2015-05-06 张家港兴业钢管有限公司 生产无缝钢管用穿孔机

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102773303B (zh) * 2012-07-16 2014-07-30 中国船舶重工集团公司第七二五研究所 一种铜镍合金大规格厚壁无缝管材制造工艺
JP5858206B1 (ja) * 2014-03-19 2016-02-10 新日鐵住金株式会社 継目無金属管の製造方法
WO2021220653A1 (ja) * 2020-04-30 2021-11-04 Ｊｆｅスチール株式会社 傾斜圧延設備、継目無素管の製造方法および継目無鋼管の製造方法

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5636542A (en) * 1993-11-02 1997-06-10 Sumitomo Metal Industries, Ltd. Piercing-rolling method and piercing/rolling apparatus for seamless steel tube
US5813962A (en) * 1996-06-28 1998-09-29 Kawasaki Steel Corporation Forged roll for rolling a seamless steel pipe
US6073331A (en) * 1995-05-19 2000-06-13 Nkk Corporation Method for manufacturing seamless pipe
US20070062238A1 (en) * 2004-05-28 2007-03-22 Kouji Nakaike Method for manufacturing seamless steel pipe or tube

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JP2898775B2 (ja) * 1991-04-17 1999-06-02 川崎製鉄株式会社 継目無鋼管の傾斜圧延方法
JPH07102372B2 (ja) * 1991-09-12 1995-11-08 川崎製鉄株式会社 管傾斜圧延方法
JPH06262219A (ja) 1993-03-16 1994-09-20 Nippon Steel Corp 鋼管圧延用ディスクガイドロール
CN1141191C (zh) * 1995-05-10 2004-03-10 住友金属工业株式会社 用于无缝钢管的穿孔／轧制方法和设备
JPH1081937A (ja) * 1996-06-28 1998-03-31 Taiheiyo Seiko Kk 継目無鋼管圧延用鍛造ロール及びその製造方法
JPH11285709A (ja) 1998-04-01 1999-10-19 Nippon Steel Corp 継ぎ目無し鋼管穿孔および圧延用ガイドシュー
JP3633434B2 (ja) 1999-07-26 2005-03-30 住友金属工業株式会社 マルテンサイト系ステンレス継目無鋼管の製造方法
JP4958346B2 (ja) 2001-08-10 2012-06-20 住友金属工業株式会社 継目無管の製造方法

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5636542A (en) * 1993-11-02 1997-06-10 Sumitomo Metal Industries, Ltd. Piercing-rolling method and piercing/rolling apparatus for seamless steel tube
US6073331A (en) * 1995-05-19 2000-06-13 Nkk Corporation Method for manufacturing seamless pipe
US5813962A (en) * 1996-06-28 1998-09-29 Kawasaki Steel Corporation Forged roll for rolling a seamless steel pipe
US5950310A (en) * 1996-06-28 1999-09-14 Kawasaki Steel Corporation Forged roll for rolling a seamless steel pipe and manufacturing method of same
US20070062238A1 (en) * 2004-05-28 2007-03-22 Kouji Nakaike Method for manufacturing seamless steel pipe or tube

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104588411A (zh) * 2015-01-26 2015-05-06 张家港兴业钢管有限公司 生产无缝钢管用穿孔机

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CN101980801A (zh) 2011-02-23
JP4371247B2 (ja) 2009-11-25
CN101980801B (zh) 2012-12-05
MX2010010438A (es) 2010-12-15
EP2286934A1 (en) 2011-02-23
JP2009241075A (ja) 2009-10-22
BRPI0822466A2 (pt) 2015-06-16
EP2286934A4 (en) 2013-10-09
WO2009118957A1 (ja) 2009-10-01
EP2286934B1 (en) 2015-03-04
BRPI0822466B1 (pt) 2020-04-22

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