Automatic temperbead repair of Cr-Mo steels

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:234176

Payne, R J ^[1]; Roberts, B W ^[2]

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1. Welding Services Inc., Atlanta, GA (United States). Specialty Services
2. Tennessee Valley Authority, Chattanooga, TN (United States). Component Damage Assessment

Welding Services Inc. (WSI) in cooperation with the Tennessee Valley Authority (TVA) has qualified a procedure for the application of the automatic GTAW temperbead process to the repair of P-No. 5 (2-1/4% Cr) materials utilizing matching (AWS A5.28, ER90S-B3L) filler material. The qualification was performed in accordance with the qualification requirements and intent of ASME Section 11 and Code Case N-432. The primary challenges for successful completion of this procedure are the Heat Affected Zone (HAZ) grain refinement and the self tempering of the filler metal itself. These are especially important because of the inherent hardenability of the 2-1/4% Cr material. The developmental methodology used in the determination of optimal welding parameters and associated grain refinement and tempering effect is unique in that geometric weld penetration definition is utilized as a primary development criteria as opposed to heat input. The compelling justification for the application of automatic GTAW temperbead techniques to the repair of power plant components lies in the potential detrimental effects of thermal heat treatment and the associated cost and schedule impact. Where repair geometry allows, the automatic process provides highly predictive results and is preferred over a manual SMAW Half Bead repair. The repair of steam valve critical features and turbine casing repairs are but two examples of the applicability of the automatic technique. The application of the developed automatic technique to heavy wall headers and piping components utilizing the Cr-Mo steels is a natural extrapolation of the current project.

• OSTI ID: 234176
• Report Number(s): CONF-9411168--; ISBN 0-87171-444-2
• Country of Publication: United States
• Language: English

Related Subjects

20 FOSSIL-FUELED POWER PLANTS
22 GENERAL STUDIES OF NUCLEAR REACTORS
36 MATERIALS SCIENCE
AUTOMATION
EQUIPMENT
FILLER METALS
FOSSIL-FUEL POWER PLANTS
GAS TUNGSTEN-ARC WELDING
GRAIN REFINEMENT
HEAT AFFECTED ZONE
LOW ALLOY STEELS
MECHANICAL PROPERTIES
NUCLEAR POWER PLANTS
REPAIR
STANDARDS
STEEL-CR2MO