基本信息:
- 专利标题： 継目無鋼管
- 专利标题（英）：SEAMLESS STEEL PIPE
- 申请号：JP2020060972 申请日：2020-03-30
- 公开(公告)号：JP2021161438A 公开(公告)日：2021-10-11
- 发明人： 神谷 裕紀 , 相馬 貴志
- 申请人： 日本製鉄株式会社
- 申请人地址： 東京都千代田区丸の内二丁目6番1号
- 专利权人： 日本製鉄株式会社
- 当前专利权人： 日本製鉄株式会社
- 当前专利权人地址： 東京都千代田区丸の内二丁目6番1号
- 代理人： アセンド特許業務法人
- 主分类号： C22C38/54
- IPC分类号： C22C38/54 ; C22C38/00
To provide a seamless steel pipe that has 758 MPa or more of yield strength and excellent SSC resistance, and in which a surface flaw is difficult to be formed on a processed surface even if processed surface is formed on a pipe end part.SOLUTION: A seamless steel pipe has a chemical composition containing C:0.15 to 0.45%, Si:0.05 to 1.00%, Mn:0.05 to 1.50%, P:0.030% or less, S:0.0050% or less, Cr:0.30 to 1.50%, Mo:0.25 to 2.00%, Ti:0.002 to 0.030%, Al:0.005 to 0.100%, N:0.0100% or less, and O:0.0050% or less in mass%, and has yield strength of 758 MPa or more. In the case where a wall thickness is D, macro-streak-flaws are 2.0 pcs./100 cm2 or less at 0.3D depth position from an external surface of the seamless steel pipe.SELECTED DRAWING: None