Atomic Hydrogen Welding in Aircraft Production

In the early part of last year, the author was asked to examine and report on a number of welded test pieces. These test pieces were cruciform joints in T.45 tube, and had been oxy‐acetylene welded by skilled aircraft welders using DTD. 82A (soft iron) filler rod and had been tensile tested. The tubes were rather larger than are commonly met with in aircraft practice, being 1½ in. o/d and 16G. and 10G. in thickness. Some of the test joints comprised tubes of equal thickness and others of unequal thickness. The lighter gauge tubes were generally satisfactory, all failures occurring in the tube away from the welds, but the heavy gauge tubes all failed in the welds and showed that difficulty had been experienced in obtaining adequate penetration without the welds becoming over‐heated and of excessive size. These indications were still more pronounced in the joints comprising tubes of unequal size in that, in spite of all failures occurring in the lighter gauge tubes, the latter suffered from excess penetration and some oxidation, and the welds on the heavy tubes lacked penetration and were in parts defective. These findings suggested that oxy‐acetylene welding was not suitable for this particular application.