Accession Number : AD0459673

Title :   THE EFFECT OF HEAT TREATMENT ON THE STRENGTH AND TOUGHNESS OF PROMISING 130 TO 150 KSI YIELDSTRENGTH SUBMARINE-HULL STEELS.

Descriptive Note : Technical progress rept.,

Corporate Author : UNITED STATES STEEL CORP MONROEVILLE PA APPLIED RESEARCH LAB

Personal Author(s) : Dabkowski, D. S. ; Manganello, S. J. ; Porter, L. F.

Report Date : 20 MAR 1963

Pagination or Media Count : 41

Abstract : Because of the need for a submarine-hull steel that would permit submarines to operate at depths significantly greater than those now attainable with HY-80 steel hulls, a test was made to develop a steel that has a minimum yield strength of 150,000 psi and good notch toughness at ice-water temperatures and that can be satisfactorily fabricated into submarine hulls in plate thicknesses through 4 inches. Recently, the yield-strength objective was reduced to 130,000 to 150,000 psi because prospects for the development of a suitable filler metal were believed to be much better in the lower yieldstrength range. The Applied Research Laboratory determined the effect of variations in the austenitizing and tempering temperatures on the mechanical properties of the following four steels considered promising as HY-130/150 steels: HY-80, 3 3/4Ni-Cr-Mo-V, 5 1/4Ni-Cr-Mo-V, and 7 1/2Ni-Cr-Mo steels. Since the 5 1/4Ni-Cr-Mo-V steel exhibited the best combination of yield strength, notch toughness, and heat-treating characteristics that could be readily controlled on production facilities, there appears to be no advantage in increasing the nickel content of Ni-Cr-Mo submarine-hull steels above about 5 percent. (Author)

Descriptors :   (*SUBMARINE HULLS, STEEL), (*STEEL, MECHANICAL PROPERTIES), HEAT TREATMENT, TOUGHNESS, MATERIAL FORMING, SHIP PLATES, NICKEL, CHROMIUM, MOLYBDENUM, CHEMICAL ANALYSIS.

Distribution Statement : APPROVED FOR PUBLIC RELEASE