Study of the Seam Welding Process Applied to Prevent Stress Cracking of the Visor of the M1 Helmet

摘要

The edge annealing process has been found effective in preventing the progress of cracks through the annealed zone. Since any cracks which may form between the edge and the annealed zone are short enough to be covered by the stainless steel edging it is believed that the application of the edge-annealing process immediately after the visor speaking operation would correct the visor cracking difficulties being presently experienced by the helmet fabricators. Recent experience with a 3 1/2% nickel manganese steel shows a sufficient superiority over normal manganese steel that the edge-annealing process probably would not be required to safeguard against delayed visor cracking. (Author)