发明名称 |
Chemical conversion treatment liquid |
摘要 |
A chemical conversion treatment liquid which can stably form a phosphate-type chemical conversion film on a steel material for a joint portion of an oil well steel pipe containing 0.5-13% Cr is developed. Using a chemical conversion treatment liquid to which a prescribed amount of potassium is added, a chemical conversion film containing a prescribed amount of potassium compounds and having a prescribed thickness can be formed on the threaded surface of a joint portion of an oil well steel pipe. |
申请公布号 |
US8333847(B2) |
申请公布日期 |
2012.12.18 |
申请号 |
US201113039656 |
申请日期 |
2011.03.03 |
申请人 |
IZAWA MASARU;GOTO KUNIO;SUMITOMO METAL INDUSTRIES, LTD. |
发明人 |
IZAWA MASARU;GOTO KUNIO |
分类号 |
C23C22/07;C23C22/18;C23C22/00;C23C22/08;C23C22/12;C23C22/50;C23C22/62 |
主分类号 |
C23C22/07 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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