Development of temper-bead technique applied to dissimilar welded joints of nuclear pressure vessels
When nuclear pressure vessels made of low-alloy steel (P-3 Group 3) need repair or modification, technical standards for welding of electrical structures should be applied, and then postweld heat treatment (PWHT) should be done. However, cases in which PWHT is impractical are theoretically possible due to a variety of restrictions. To deal with such a problem, there is a regulation for repair weld technique, without PWHT, in accordance with ASME B and PV Code. This method is called temper-bead technique, which gives the weldments sufficient toughness by tempering the hardened zone of the heat-affected zone on the first layer of the base metal using the heat of the following weld beads. Because there is no regulation in Japan covering this method, a procedure is required to perform it under a special license, after a verification test has been passed. An attempt has been made to develop a method, on the supposition that the temper-bead technique is adopted for replacement of what is called dissimilar welded joints, so that a nickel base alloy is buildup welded at the tip of the nozzle of the low-alloy steel pressure vessel, and a stainless steel pipe is butt welded.
- OSTI ID:
- 471166
- Journal Information:
- Bulletin - Welding Research Council, Journal Issue: 412; Other Information: PBD: Jun 1996
- Country of Publication:
- United States
- Language:
- English
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