Irradiation Strengthening and Fracture Embrittlement of A533-B Pressure Vessel Steel Plate and Submerged-Arc Weld

Abstract

Plate and weld material of ASTM A533 Grade B, Class 1 steel furnished by the Heavy Section Steel Technology Program was characterized for irradiation strengthening and fracture embrittlement. Plane strain fracture toughness, K Ic, in the longitudinal orientation was determined ftom specimens irradiated at 540 F (282 C) to neutron fluence levels of 2 and 8 × 1019 n/cm2 (E > 1 MeV); longitudinal tension specimens were irradiated at 510 F (265 C) at 2, 4, 6, and 8 × 1019 n/cm2 (E > 1 MeV). Yield strength was more sensitive to irradiation strengthening than the ultimate strength, and the yield strength increase (Δσys, ksi) as a function of fluence (Ф) and temperature (T, deg. F) may be described by: Δσys = 22 [1- exp (-Φ/5 × 1018)] + Φ/1019(4.3−0.0038T) Irradiation levels of 2 and 8 × 1019 produced shifts of 185 F (103 C) and 275 F (153 C) in the 50-ksi√in KIc fracture toughness transition of A533 plate; the measured shifts agree closely with those predicted, 153 F (85 C) and 282 F (157 C), from a proposed correlation of shift in transition and change in yield strength. Fracture toughness KIc and tensile properties of plate material were independent of the orientation. The fracture toughness of ASTM A533-B submerged-arc weldment metal irradiated at 540 F (282 C) to a fluence of 3 × 1019 n/cm2 (E > 1 MeV) exhibited a marked sensitivity for irradiation embrittlement; the indicated shift of the 50-ksi√in KIc fracture toughness transition level was approximately 390 F. The yield and ultimate tensile strengths of ASTM A533-B sub-arc weld were determined for 510 F (265 C) irradiations to fluences of 0.5 × 1019 n/cm2 and 4.0 to 4.6 × 1019 n/cm2 (E > 1 MeV). Irradiation strengthening of weld yield properties is slightly greater than the longitudinal base properties.

Multiscale modeling of crystal plasticity in Reactor Pressure Vessel steels: Prediction of irradiation hardening

“…At the first glance, this appears to be in contradiction with experimental results (see for ex. [66,67]). Our interpretation of this discrepancy is that the offset of 0.2% for the measurement of the yield stress is not the most appropriate.…”

In situ micro tensile testing of He+2 ion irradiated and implanted single crystal nickel film

“…The effect of such microstructural changes caused by irradiation on the mechanical properties of structural materials has been the subject of intense study in the past few decades. Such studies have been integral to the worldwide effort to produce materials with greater resistance to higher irradiation doses for future designs of nuclear reactors [2,3]. Ion beam irradiation has been a method of choice to simulate the effects of neutron irradiation in a reactor for some time [4,5], since it enables the attainment of reasonable doses within hours, instead of years inside a reactor.…”