Corrosion radiographic detection

Visual identification prior to failure is difficult due to the typical tightness of stress-corrosion cracks. A low-power hand lens will greatly aid determination. Crack enhancement may be achieved through the use of dye penetrants. Severe cracking may be detectable using ultrasonic, radiographic, or acoustic emission techniques. 

Loop G-Run 2, IIVL I-Run 5, and HVL II-Run 1 are still under test. In these loops are. specimens of 2 % Cr-1% Mo and %% Cr-1/2% Mo steels having variou.s heat treatments, AISI type—110 and Bessemer steels, and welds made with % Cr-1/2% Mo, 2 % Cr-l7o Mo, 5% Cr-1/2% Mo, AISI type-410 and mild steel bare filler rods. No corrosion has been defected radiographically in the loop G test section after 2500 hr of operation. Xo corrosion has been detected in the HVL I-Run 5 test section however, slight dcpo.sition has been detected in the finned cooler. This precipitate was fii-st observed aftei 1400 hr of operation but is still not serious after 4000 hr,... 

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