NOTCH STRENGTH OF HEAT-TREATED 4340 STEEL AS AFFECTED BY SUBSEQUENT COLD DRAWING AND AGING

摘要

The effects of cold drawing and of cold drawing and aging on the notch tensile strength of quenched and tempered 4340 rod have been investigated. The rods were heat treated, reduced up to 40 percent by cold drawing, and aged at room temperature or at 400 F Drawing was done at speeds of 10 to 40 feet per minute with a back-pull of 0 to 16,650 pounds. The notch tensile strength of the cold-drawn rods increased with increasing yield strength up to approximately 211,000 psi. This was followed by a decrease in the notch strength The magnitude of the aging effect on the notch tensile strength was influenced by the tempering temperature and the drawing conditions.