Accession Number : AD0474241

Title :   AN INVESTIGATION OF THE MECHANICAL PROPERTIES AND MICROSTRUCTURES OF 18NI(250) MARAGING STEEL WELDMENTS.

Descriptive Note : Summary rept. 15 Jun 64-15 Aug 65,

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

Personal Author(s) : Reisdorf, B. G. ; Birkle, A. J. ; Cox, P. H. Salmon

Report Date : NOV 1965

Pagination or Media Count : 174

Abstract : The purpose of this project is to relate the microstructural features of 18Ni(250) maraging steel weldments to their fracture toughness properties. Fractographic examination of broken notch-bend test specimens from the fusion zones of both the tungsten-inert-gas (TIG) and the submerged-arc (SA) weldments indicates that the fracture proceeds primarily along the cell boundaries or dendrite interstices that were formed during solidification. These regions, being the last to solidify, are high in inclusion content, and electron-probe microanalyses show these regions to be enriched in Ni, Ti, and Mo. Approximately 90% of the fracture surface of the TIG weld specimens exhibited a dimpled structure indicative of a high level of fracture toughness, whereas only about 70% of the fracture surface of the SA weld specimens exhibited a dimpled fracture surface. (Author)

Descriptors :   *WELDS), (*MARAGING STEELS, MECHANICAL PROPERTIES, MICROSTRUCTURE, TENSILE PROPERTIES, FRACTURE(MECHANICS), TOUGHNESS, NOTCH TOUGHNESS, DEFORMATION, HEAT TREATMENT, PHOTOMICROGRAPHY, AGING(MATERIALS), HIGH TEMPERATURE.

Subject Categories : Properties of Metals and Alloys
      Couplers, Fasteners, and Joints

Distribution Statement : APPROVED FOR PUBLIC RELEASE