Accession Number : AD0858946

Title :   Metallurgical Investigations of 10Ni-2Cr-1Mo-8Co Steel.

Descriptive Note : Research and development rept.,

Corporate Author : NAVAL SHIP RESEARCH AND DEVELOPMENT LAB ANNAPOLIS MD

Personal Author(s) : Cox, T. B. ; Schreitz, W. G. ; Czyryca, E. J. ; Rosenstein, A. H.

Report Date : AUG 1969

Pagination or Media Count : 55

Abstract : The mechanical properties, metallography, response to heat treatment, fatigue properties, and weld heat-affected zone characteristics of 10Ni-2Cr-1Mo-8Co steel are presented. Higher yield strengths coupled with lower CVN impact energy values are associated with a microstructure of small martensitic platelets and fine carbide dispersion, while higher CVN values coupled with lower yield strengths are recorded for a microstructure of large martensitic platelets and large carbide precipitates. The optimum heat treatment for the material investigated consisted of austenitizing at 1450F (1 hour, water quench) followed by aging at 900F (5 hours, water quench) and resulted in a yield strength of 194 ksi and a CVN (0 F) energy of 105 foot-pounds. By simulating HAZ material from multipass weldments it was found that yield strengths of 180 ksi and CVN (0 F) impact energies of 50 foot-pounds can be attained in the HAZ in the as-welded condition. Further improvement of properties may be effected by aging after welding. Investigation of the fatigue properties of the steel show it to behave similarly to other quenched and tempered steels of intermediate alloy content in both air and saltwater environments. (Author)

Descriptors :   (*SHIP STRUCTURAL COMPONENTS, STEEL), (*STEEL, MECHANICAL PROPERTIES), METALLOGRAPHY, HEAT TREATMENT, FATIGUE(MECHANICS), WELDS, MICROSTRUCTURE, AGING(MATERIALS), CORROSION, IMPACT SHOCK, SHOCK RESISTANCE, COBALT ALLOYS, CHROMIUM ALLOYS, MOLYBDENUM ALLOYS, NICKEL ALLOYS.

Subject Categories : Properties of Metals and Alloys
      Marine Engineering

Distribution Statement : APPROVED FOR PUBLIC RELEASE