Session: CS-22-02 Temper Bead Welding Advancements for Repair and Replacement

Paper Number: 107489

107489 - Elimination of the 48-Hour Hold for Ambient Temperature Temper Bead Welding With Austenitic Weld Metal 

Temper bead welding rules and requirements in the ASME Section XI code and code cases have historically required a 48-hour hold (wait period) after the temper bead weld layers are complete and the weldment has cooled to ambient temperature prior to performing the final nondestructive examination (NDE). The purpose of the 48-hour wait period is to ensure that if delayed hydrogen induced cracking (HIC) occurs it is detected by the final acceptance examination of the temper bead weldment. Delayed HIC is known to occur up to 48 hours after a weldment cools to ambient temperature when appropriate welding techniques and low hydrogen practices are not used.  A recent revision to Case N-888, “Similar and Dissimilar Metal Welding Using Ambient Temperature SMAW or Machine GTAW Temper Bead Technique,” eliminates the 48-hour hold for temper bead welds on P-No. 1 and P-No. 3 base material when austenitic weld metal is used. This paper summarizes the technical basis for eliminating the 48-hour hold and provides an extensive list of successful ambient temperature temper bead weld repairs that demonstrates the 48-hour hold is inconsequential and there is no potential for delayed HIC when temper bead welding is deployed with low hydrogen practices and austenitic weld metal.

Presenting Author: Asif Patel Southern Nuclear Operating Company

Presenting Author Biography: Asif is an experienced welding engineer and has worked at Southern Nuclear Operating Company for over 8 years. He is skilled in materials science, welding engineering, and repair and replacement codes and standards. Asif studied material science and engineering at the University of Alabama, Birmingham and welding engineering at the Ohio State University.
Asif is active in ASME Section XI Task Group Temper Bead and Working Group Welding and Special Repair Processes.

Authors:

Steven L. McCracken EPRI
Asif Patel Southern Nuclear Co.