Method for preventing disbonding of weld-cladding

• US 4,564,402 A
• Filed: 08/21/1984
• Issued: 01/14/1986
• Est. Priority Date: 08/25/1983
• Status: Expired due to Term

• Current Assignee: Ishikawajima-Harima Jukogyo Kabushiki Kaishe
• Original Assignee: Ishikawajima-Harima Jukogyo Kabushiki Kaisha
• Inventors: Morishige, Norio, Kume, Ryoichi
• Primary Examiner(s): NOT, DEFINED
• Application Number:
  US06/642,789
• Time in Patent Office: 511 Days
• Field of Search: 148/127, 148/134, 148/143, 148/16, 148/14, 148/12 E, 148/38, 428/683, 428/685, 208/154, 208/209, 208/210, 219/76.12
• US Class Current: 148/529
• CPC Class Codes: B01J 19/002 Avoiding undesirable reactions or side-effects, e.g. avoiding explosions, or improving the yield by suppressing side-reactions
• CPC Class Codes: B01J 19/02 Apparatus characterised by being constructed of material selected for its chemically-resistant properties
• CPC Class Codes: B01J 2219/0286 Steel
• CPC Class Codes: C21D 3/06 Extraction of hydrogen
• CPC Class Codes: C21D 9/50 for welded joints

Abstract

Disclosed is a method for preventing hydrogen-induced disbonding of austenitic stainless steel cladding, which is made on a low alloy steel, in a reactor vessel which has been used in a high-temperature and high-pressure hydrogen atmosphere. The clad steel is cooled from its operating temperature to a temperature which is not lower than 100° C. Then, the clad steel is maintained at a temperature between said temperature which is not lower than 100° C. and a postweld heat treatment so as to effect hydrogen degassing treatment. Thereafter, the clad steel is further cooled.

Claims

1. A method for preventing, during cooling to room temperature, hydrogen-induced exfoliation of austenitic stainless steel from a cladding of said stainless steel welded to the inside of a steel reaction vessel, after exposure to a reaction under high temperature and high pressure hydrogen atmosphere, comprising subjecting a reaction vessel having an austenitic stainless steel cladding which would exfoliate if cooled directly to room temperature, to cooling to an initial temperature of not lower than 100°

C., maintaining said vessel at such temperature for a time sufficient to expel hydrogen from said steel, and thereafter further cooling said vessel.

2. A method according to claim 1, wherein said vessel is cooled to an initial temperature of from about 100°

C. to 720°

C.

3. A method according to claim 1, wherein said vessel is cooled to an initial temperature of from about 120°

C. to 150°

C.