Cr-PLATED MADNREL BAR FOR MANUFACTURING HOT SEAMLESS TUBE AND METHOD OF MANUFACTURING THE SAME
    1.
    发明公开
    Cr-PLATED MADNREL BAR FOR MANUFACTURING HOT SEAMLESS TUBE AND METHOD OF MANUFACTURING THE SAME 有权
    CHROME DORN ROD的用于生产热无缝管及方法生产同样

    公开(公告)号:EP1637245A4

    公开(公告)日:2007-04-18

    申请号:EP04745541

    申请日:2004-06-03

    CPC classification number: B21B25/00

    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.

    MANDREL BAR FOR HOT MANUFACTURING SEAMLESS TUBE AND HOT MANUFACTURING METHOD OF SEAMLESS TUBE

    公开(公告)号:JP2001001016A

    公开(公告)日:2001-01-09

    申请号:JP16751399

    申请日:1999-06-14

    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.

    Friction testing method and friction testing device
    9.
    发明专利
    Friction testing method and friction testing device 审中-公开
    摩擦测试方法和摩擦测试设备

    公开(公告)号:JP2012173119A

    公开(公告)日:2012-09-10

    申请号:JP2011034999

    申请日:2011-02-21

    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 translation: 要解决的问题:提供可以模拟用于制造无缝钢管的工具的损坏并评估实际使用的工具和润滑剂的性能的摩擦试验方法。 解决方案:提供了一种在制造无缝钢管期间模拟工具和轧制材料之间的摩擦的摩擦试验方法,所述摩擦试验方法包括将第一柱状试验片1和第二柱状试验片2旋转到 在第一测试件1和第二测试件2被保持的状态下分别轴1X,2X,使得轴1X,2X在第一测试片1和第二测试片2彼此挤压时不相交 第二测试件2的外周表面与第一测试件1的端面接触。版权所有:(C)2012,JPO&INPIT

    PLUG FOR PIERCING SEAMLESS STEEL TUBE AND METHOD FOR MANUFACTURING SEAMLESS STEEL TUBE

    公开(公告)号:JP2002113507A

    公开(公告)日:2002-04-16

    申请号:JP2000306688

    申请日:2000-10-05

    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.

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