Accession Number : AD0600932

Title :   THE EFFECT OF SPECIAL ADDITIONS ON THE NOTCH TOUGHNESS OF MARAGING STEELS.

Descriptive Note : Technical rept.

Corporate Author : UNITED STATES STEEL CORP MONROEVILLE PA

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

Report Date : 01 APR 1964

Pagination or Media Count : 25

Abstract : The results indicated that when Laboratory air-melted or vacuum-melted heats of 12Ni-3Cr-3Mo, 12Ni-5Cr-3Mo, or 18Ni-8Co-3Mo maraging steels contained about 0.02 percent zirconium, their notch toughness in the solution-annealed and in the solution-annealed and aged conditions was markedly lower than that of the same steels containing no boron or zirconium or containing only boron. The results also indicated that the steels containing boron were slightly more notch tough than the steels containing no boron or zirconium, and that the steels containing about 0.005 percent carbon were more notch tough than the steels containing about 0.017 percent carbon. In addition, there was some indication that the elimination of aluminum may also significantly improve notch toughness. On the basis of the above results, Laboratory and production heats of maraging steels having yield strengths in the range 180 to 210 ksi are now being melted without the special zirconium addition. Additional Laboratory studies are now in progress to determine the optimum titanium and aluminum content for maraging steels having yield strengths in the range 180 to 210 ksi, after which the effect of nickel, chromium, cobalt, and molybdenum will be investigated with the aim of developing the optimum over-all composition for these types of maraging steels. (Author)

Descriptors :   (*MARAGING STEELS, TOUGHNESS), (*BORON, METALLURGY), (*ZIRCONIUM, METALLURGY), (*STEEL, MECHANICAL PROPERTIES), NICKEL, CHROMIUM, MOLYBDENUM, COBALT, GRAIN BOUNDARIES, HEAT TREATMENT, CHEMICAL PROPERTIES, MELTING

Distribution Statement : APPROVED FOR PUBLIC RELEASE