发明名称 |
Surface conditioning prior to chemical conversion treatment of a steel member |
摘要 |
By subjecting a threaded joint for OCTG (oil country tubular goods) to surface conditioning with an aqueous solution of potassium tetraborate or sodium tetraborate prior to manganese phosphate chemical conversion treatment, a manganese phosphate chemical conversion coating having coarse crystal grains with an average crystal grain diameter of 10-110 micrometers is formed on the surface of the steel member which may be any steel including a high Cr steel. This manganese phosphate chemical conversion coating can hold a large amount of a liquid lubricant, and it is effective at preventing the occurrence of galling at the time of makeup of a threaded joint for OCTG.
|
申请公布号 |
US7666266(B2) |
申请公布日期 |
2010.02.23 |
申请号 |
US20060445151 |
申请日期 |
2006.06.02 |
申请人 |
SUMITOMO METAL INDUSTRIES, LTD. |
发明人 |
IZAWA MASARU;GODO KUNIO;UJITA YOSHIHISA;TAKANO TAKAHIRO |
分类号 |
C23C22/78;C23C22/00;C23C22/18 |
主分类号 |
C23C22/78 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|