Ground-fault neutralizer for fort peck, montana, has novel design features to combat sixty degrees below zero F
✍ Scribed by R.H.O.
- Book ID
- 103079796
- Publisher
- Elsevier Science
- Year
- 1946
- Tongue
- English
- Weight
- 149 KB
- Volume
- 242
- Category
- Article
- ISSN
- 0016-0032
No coin nor oath required. For personal study only.
✦ Synopsis
CURRENT TO~ICS.
U.F. L tried. However, when a sample was welded after being cleaned by this method the weld bead was sprinkled with a black substance which accumulated in small surface pits. The discoloration was easily brushed off, but the pits remained to mar the surface of the bead.
When it was determined that the specks were not caused by too great a percentage of nitrogen in the argon welding gas or from faulty power supply, it was deduced that the cleaning method was responsible. Since the specks were rich in nitrides, the nitric acid was blamed, and sulfuric acid was tried in its place.
After a brief degreasing in a five per cent. solution of sodium hydroxide to remove all grease, oil, or wax, and a brief wash in water to remove most of the caustic and scum, the aluminum was dipped in a fifty per cent. sulfuric acid bath. This completed removal of the oxide skin and restored most of the surface brightness, and a hot water bath removed the acid and left the aluminum clean and dry. Welding tests made on samples cleaned by this method resulted in mirror-bright, fine-contoured beads as welded.
R. H. O.