NEUTRON EMBRITTLEMENT OF 2 AUSTENITIC IRON-BASE-ALLOYS AT ELEVATED TEMPERATURES .I. INFLUENCE OF ALLOY-TYPE AND HEAT ANALYSIS

Iron-base-alloys containing nickel and chromium like XCrNiMoNb 1616 * and XCrNi 2030 * have been irradiated up to 1.4 × 1020 n/cm2 (E > MeV) at 650 °C and changes due to neutron irradiation in tensile and stress rupture characteristics at 300 and 650 °C have been established. In tensile testing an obvious decrease in 650 °-Ctotal elongation was noticeable which may be explained by a weakening of grain boundaries by helium bubble formation. The decrease in stress rupture strength of XCrNiMoNb 1616 is mainly based upon heavy increase of the secondary creep rate whereas in XCrNi 2030 alloys the grain boundary weakening seems to be more important for this reduction. For both alloy types a superiority of commercial heats over high purity qualities can be reported generally. © 1968.