EVALUATION OF 2-INCH-THICK ELECTRON-BEAM WELDMENTS.
UNITED STATES STEEL CORP MONROEVILLE PA
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Sample electron-beam weldments were fabricated from 2-inch-thick 12Ni-5Cr-3Mo steel plates at a 180 ksi yield strength and also from 2-inch-thick 5 14Ni-Cr-Mo-V steel plates at a 140 ksi yield strength by using the lowvoltage Sciaky process and also using the high-voltage Hamilton-Standard process. Radiographic and metallographic inspections disclosed that all the weldments contained defects such as lack of penetration, lack of fusion, porosity, andor microcracks. The results of mechanicalproperty tests of the 5 14Ni-Cr-Mo-V weldments indicated that, in flaw-free regions, the electron-beam weldments exhibited good strength and ductility, moderately good weldmetal toughness, and excellent heat-affected-zone toughness. The results of the mechanical-property tests of aged 12Ni5Cr-3Mo weldments indicated that, in flaw-free regions, the electron-beam weldments exhibited adequate strength but low weld-metal and weld-heat-affected-zone toughness. Generally, the evaluation of the 2-inch-thick electron-beam weldments--both the 140-ksi yield-strength 5 14Ni-Cr-MoV weldment and the 180-ksi yield-strength 12Ni-5Cr-3Mo weldment--indicated that no metallurgical advantages were derived from electron-beam welding that could not be achieved by using more conventional welding processes.