Invention Grant
- Patent Title: Method of producing steel for steel pipe excellent in sour-resistance performance
- Patent Title (中): 钢管耐腐蚀性能优良的钢管生产方法
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Application No.: US12629182Application Date: 2009-12-02
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Publication No.: US07959709B2Publication Date: 2011-06-14
- Inventor: Mitsuhiro Numata , Shingo Takeuchi , Tomohiko Omura
- Applicant: Mitsuhiro Numata , Shingo Takeuchi , Tomohiko Omura
- Applicant Address: JP Osaka
- Assignee: Sumitomo Metal Industries, Ltd.
- Current Assignee: Sumitomo Metal Industries, Ltd.
- Current Assignee Address: JP Osaka
- Agency: Clark & Brody
- Priority: JP2007-295111 20071114
- Main IPC: C21C5/28
- IPC: C21C5/28 ; C21C7/064 ; C21C7/072 ; C21C7/10

Abstract:
A method of producing steel pipe excellent in sour-resistance performance, uses comprises controlling the amount of Ca addition charged into molten steel in a ladle according to a N content in the molten steel prior to Ca addition. As a result of the controlling step, a CaO content in the inclusions is in the range of 30 to 80%, the ratio of the N content in the steel to the CaO content in the inclusions satisfies the relation expressed by equation (1), and a CaS content in the inclusions satisfies the relation expressed by equation (2). 0.28≦[N]/(% CaO)≦2.0 (1) (% CaS)≦25% (2) where [N] represents the mass content (ppm) of N in the steel, (% CaO) represents the mass content (%) of CaO in the inclusions, and (% CaS) represents the mass content (%) of CaS in the inclusions.
Public/Granted literature
- US20100071509A1 METHOD OF PRODUCING STEEL FOR STEEL PIPE EXCELLENT IN SOUR-RESISTANCE PERFORMANCE Public/Granted day:2010-03-25
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