Effect of Scratches on Pinch Welds

Korinko, P

Savannah River Site (S.C.)

关键词: Surface Properties;    Nondestructive Testing;    Tritium;    Welding;    42 Engineering;   

DOI  :  10.2172/890203
RP-ID  :  WSRC-TR-2005-00435
RP-ID  :  DE-AC09-96SR18500
RP-ID  :  890203

美国|英语

来源: UNT Digital Library

【 摘 要 】

Fill stems for tritium reservoirs have stringent scratch requirements such that any indications that appear to have depth are cause for rework or rejection. A scoping study was undertaken to evaluate the effect of scratches approximately 0.0015 to 0.002 inch deep on the fitness for service and bond quality. The stems were characterized using borescope before and after welding. The four stems were welded with near optimal weld parameters, proof tested, and examined metallographically. The stems were radiographed, proof tested, and examined metallographically. The scratches did not adversely affect (1) the weld integrity based on radiography, (2) the ability to withstand the proof pressure, and (3) the weld quality based on metallographic cross-sections. Based on these limited results at a nominal weld current, the weld process is very robust. It may be able to recover from manufacturing defects and inspection anomalies worse than those expected for typical fill stem manufacturing processes; additional testing specific to each application over a range of weld heats is needed to verify applicability of these results.