METHOD FOR MANUFACTURING SEAMLESS STEEL PIPE
    2.
    发明公开
    METHOD FOR MANUFACTURING SEAMLESS STEEL PIPE 有权
    工艺无缝钢管

    公开(公告)号:EP1284167A4

    公开(公告)日:2005-11-09

    申请号:EP02705439

    申请日:2002-03-22

    申请人: JFE STEEL CORP

    摘要: A method for manufacturing a seamless steel pipe which is excellent in properties of its inner surface and its wall. A round billet having a center segregation zone parting degree W (%) of 20 % or more, defined by the following formula, is used as its material. W (%) = ( DELTA w/D) x 100 (wherein W is the center segregation band parting degree (%), DELTA w is the center segregation zone parting width (mm) at the thickness center of the round billet, and D is the external diameter (mm) of the round billet). The round billet is pierced into a hollow blank pipe while maintaining the temperature at a predetermined temperature, and is then formed into a steel pipe of a predetermined size by elongating or by elongating and drawing the blank pipe. The continuously cast slab is preferably a slab cast by using a molten steel the overheat temperature of which is 25 to 65 DEG C, using secondary cooling water is such a way that the amount of secondary cooling water at the central portion of the slab width is greater than that at the peripheral portion in the slab width direction, and that the ratio of the secondary cooling water till the complete solidification is 1.2 to 2.0 l/kg-steel.

    STAINLESS-STEEL PIPE FOR OIL WELL AND PROCESS FOR PRODUCING THE SAME
    4.
    发明公开
    STAINLESS-STEEL PIPE FOR OIL WELL AND PROCESS FOR PRODUCING THE SAME 有权
    ROHR AUS NICHTROSTENDEM STAHLFÜRÖLQUELLEUND HERSTELLUNGSVERFAHRENDAFÜR

    公开(公告)号:EP1514950A4

    公开(公告)日:2005-07-20

    申请号:EP03733478

    申请日:2003-06-18

    申请人: JFE STEEL CORP

    摘要: A stainless-steel pipe with excellent corrosion resistance for oil wells, characterized by having a composition which comprises, in terms of wt.%, up to 0.05% carbon, up to 0.5% silicon, 0.20 to 1.80% manganese, up to 0.03% phosphorus, up to 0.005% sulfur, 14.0 to 18.0% chromium, 5.0 to 8.0% nickel, 1.5 to 3.5% molybdenum, 0.5 to 3.5% copper, up to 0.05% aluminum, up to 0.20% vanadium, 0.01 to 0.15% nitrogen, up to 0.006% oxygen, and iron and unavoidable impurities as the remainder, provided that Cr+0.65Ni+0.6Mo+0.55Cu-20C≥18.5 and Cr+Mo+0.3Si-43.5C-0.4Mn-Ni-0.3Cu-9N≤11 (wherein Cr, Ni, Mo, Cu, C, Si, Mn, and N mean the contents of the respective elements (wt.%)).

    摘要翻译: 1,一种对油井具有优异耐腐蚀性的不锈钢管,其特征在于其组成按重量百分比计包含至多0.05%的碳,至多0.5%的硅,0.20至1.80%的锰,至多0.03% 磷,高达0.005%的硫,14.0-18.0%的铬,5.0-8.0%的镍,1.5-3.5%的钼,0.5-3.5%的铜,至多0.05%的铝,至多0.20%的钒,0.01-0.15%的氮, 如果Cr + 0.65Ni + 0.6Mo + 0.55Cu-20C≥18.5且Cr + Mo + 0.3Si-43.5C-0.4Mn-Ni-0.3Cu-20C≥18.5,则氧含量高达0.006%,余量为铁和不可避免的杂质。 9N≤11(其中Cr,Ni,Mo,Cu,C,Si,Mn和N是指各元素的含量(重量%))。