Title:
PASSIVATION TREATMENT OF STAINLESS STEEL SURFACE
Document Type and Number:
Japanese Patent JP3045425
Kind Code:
B2
Abstract:
PURPOSE: To improve the corrosion resistance of a steel surface against a corrosive substance by executing baking while flushing a chemically non-reactive dry gas fluid on the surface of a stainless steel to be passivated.
CONSTITUTION: When a stainless steel pipe 12, for example, is baked, a pipe 12 is arranged in a chamber 14 and connected to an inlet line 20 and an exhaust line 22 through shaft couplings 24, 26 and a voltage is applied to coils 16, 18 to heat the chamber 14 and the pipe 12. At the same time, valves 32, 36, 40 are opened, an Ar gas in which the moisture content is reduced to approximately ≤10.0 ppb by a purifier 30, is fed to continuously flush the inside of the pipe 12 with the dry fluid and to make the inside of the chamber 14 in the atmosphere of the inert gas. When the baking is completed, the power supply of the coils 16, 18 is disconnected to cool the pipe 12. After the cooling is completed, the valve 32 is closed and the pipe 12 is taken out of a furnace 10. The baking temperature and the baking time are preferably approximately 250.0-500.0°C and approximately four hours or more, respectively.
Inventors:
Jeffrey Davidson
Robert Sherman
Richard Pacier
Takashi Sakanaka
Shigeki Hayashi
Yoshiyuki Nakahara
Robert Sherman
Richard Pacier
Takashi Sakanaka
Shigeki Hayashi
Yoshiyuki Nakahara
Application Number:
JP11372492A
Publication Date:
May 29, 2000
Filing Date:
May 06, 1992
Export Citation:
Assignee:
THE BOC GROUP INCORPORATED
Osaka Oxygen Industry Co., Ltd.
Osaka Oxygen Industry Co., Ltd.
International Classes:
C23C8/02; C23C8/06; C23C8/10; (IPC1-7): C23C8/06; C23C8/02
Attorney, Agent or Firm:
Kazuo Shamoto (5 outside)