发明名称 |
Steel products having superior weathering, method of producing the steel products, and method of forming weathering protective rust on steel product surfaces |
摘要 |
The invention provides a steel product having superior weathering which is coated with a rust layer containing 50 or more weight % of non-crystalline rust, a method of producing the steel product, and a method of forming weathering protective rust on a material surface of the steel product. A material of a steel product is placed in an atmosphere in which the dew point is kept constant and the temperature of the steel product material is repeatedly varied between a temperature range of 5 DEG C or more higher than the dew point and a temperature range of 5 DEG C or more lower than the dew point. Weathering protective rust is thereby formed on the material surface of the steel product and a steel product having superior weathering is obtained. Preferably, the atmosphere contains 15 to 50 volume % of oxygen gas, and the temperature of the steel product is varied at a rising rate of 0.1 to 2 DEG C/minute and a lowering rate of 0.01 to 2 DEG C/minute. Alternatively, a desired steel product can also be obtained by placing a material of the steel product in an atmosphere containing 15 to 50 volume % of oxygen gas, keeping constant the dew point in the atmosphere, and keeping the temperature of the steel product material in the atmosphere at a certain value in a temperature range between a temperature 5 DEG C lower than the dew point and a temperature 20 DEG C lower than the dew point; or by placing a material of the steel product in an atmosphere containing 15 to 50 volume % of oxygen gas, and forming and keeping a water film with a thickness not more than 500 mu m but not less than 50 mu m on a material surface of the steel product. |
申请公布号 |
EP0928836(A1) |
申请公布日期 |
1999.07.14 |
申请号 |
EP19990100258 |
申请日期 |
1999.01.08 |
申请人 |
KAWASAKI STEEL CORPORATION |
发明人 |
YAMANE, YASUYOSHI;SHIOTANI, KAZUHIKO;KAWABATA, FUMIMARU;HOSHINO, TOSHIYUKI;AMANO, KENITI;NISHIMURA, KIMIHIRO |
分类号 |
C23C8/14;C23C8/18 |
主分类号 |
C23C8/14 |
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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