Sub‐zero Quenching and Cold Cycling: A QUENCHING TECHNIQUE THAT SAVES TOOLS AND TIME

The El Segundo Division of the Douglas Aircraft Company, Inc., spearheaded by Mr. Delaney, head of department, have evolved a method of sub‐zero quenching and cold cycling which has made considerable savings in many manufacturing departments, improved finishes and prevented many breakages during forming operations. It has been applied to aluminium, steel, titanium, phenolic and other materials. The method has also been applied as a thermo‐shock treatment during machining operations allowing forgings to be machined without distortion, and, for example, chrome molybdenum parts to be band sawn in half previous times. In fact, this material, hardened to 260/280,000 lb/sq.in. was machined on a lathe at spindle speeds and rates impossible to achieve by conventional methods.