粉末冶金法で作製したニッケル基耐熱合金の高温強度に及ぼす炭素およびボロン量の影響

概要

論文の詳細を見る
Effects of boron and carbon contents on tensile properties at 760℃ were investigated for Ni-base PM-alloys with compositions fixed for main components (content of gamma prime phase : 65%). The obtained results were compared with those of cast alloys with the same composition of main component. When specimens were prepared by powder-metallurgical procedures-HIP-consolidation of alloy powder, superplastic forging of it, or additional heat treatment on either of the former two-, Yield Strength (YS), Ultimate Tensile Strength (UTS) and Elongation to fracture (EL) were improved by addition of a small amount of boron (say 0.02%) except for the case of as-forged products. However, EL deteriorated by further increase in boron content, although UTS and YS remained almost unchanged. YS, UTS and elongation deteriorated, when carbon content increased from 0.02% to 0.20%. The properties of the HIPed or forged products were improved by an appropriate heat treatment. When specimens were prepared by casting, trend seen for as-cast products was not much different from what was seen for as-HIPed ones. After the same heat treatment, however, the properties abruptly deteriorated. EL vanished and UTS decreased by more than 30%.
1990-03-01