Microstructure and mechanical properties of F82H weld metal irradiated in SINQ target-3

Experimental assessment of temperature distribution in heat affected zone (HAZ) in dissimilar joint between 8Cr-2W steel and SUS316L fabricated by 4 kW fiber laser welding

“…Based on the selected area diffraction analysis, an FCC-based structure precipitate with the lattice parameter of 1.05 nm was identified. This value is quite close to the literature where 1.06 nm was reported for M23C6 type particle in F82H (Jia and Dai (2004)). Besides, Chemical composition of Cr and C of them evaluated from EPMA were 14.5 and 0.82 wt.%, respectively.…”

“…Characteristic X-rays detected in EPMA contains signals from a certain volume which is much larger than the probe size due to the scattering the electron beam inside specimen (Kanaya et al (1972)). The probe size and sampling step of EPMA were ≈100 nm and 60 nm, respectively, and the average particle size of M23C6 in F82H was approximately 100 nm (Jia and Dai (2004)). Therefore, one should expect the measured composition contains much information from both precipitates and matrix.…”

Specific welds for test blanket modules

“…The results of single-step heat treatments clearly show that longer tempering periods do not affect the hardness (PWHT 8, 11, and 13). Furthermore, below tempering temperatures of 700°C the hardness increases clearly above 300 HV1 (PWTH 7-9) and for temperatures of 700°C and above there is not much difference (PWHT [10][11][12][13][14]. Only a two-step heat treatment (PWHT 15) softens the fusion zone to values of about 250 HV1.…”

“…Fusion welding may be performed either by electron beam (with and without filler wire), laser beam, hybrid MIG/ laser [5][6][7], or by tungsten-inert-gas (gas tungsten arc) welding with filler wire. Mechanical properties and microstructure of some electron beam (EB) and tungsten-inert-gas (TIG) welds of reduced activation 8-9Cr-WVTa steels (like EUROFER) and 9Cr-MoVNb steels (like P91) have been already investigated in the past, even after neutron irradiation [8][9][10][11][12][13][14][15][16][17][18][19][20].…”

Micro-hardness measurement and micro-structure characterization of T91 weld metal irradiated in SINQ Target-3

“…7 gives the dose dependence of the size and density of defect clusters in the T91-EBW weld metal. The data of the F82H and T91 base metal and the F82H weld metal from previous results [16,17] was also plotted for a comparison. Both materials give similar results and also the densities and the mean sizes of defect clusters in the weld metal are comparable with those in the base metal.…”