Study on Corrosion Behavior of Weld Bead by Tungsten Inert Gas Welding China Low Activation Martensitic Steel in Static Oxygen-Saturated Pb-Bi at 500°C

Environmental degradation of structural materials in liquid lead- and lead-bismuth eutectic-cooled reactors

“…On the contrary, Mustari et al [261,262] found that the fusion zone of welds prepared by TIG, yttrium-aluminium-garnet (YAG) or EB welding had much thicker oxide scales than the base metal (HCM12A F/M steel) exposed to liquid LBE with C O ≈ 4.7 × 10 − 6 wt% or C O ≈ 7 × 10 − 7 wt% at 600 • C and 650 • C for 500 h. This observation is in accordance with the results reported by Wang et al [263]. Moreover, Chen et al [264][265][266] reported that both the TIG weld and base metal of a China Low Activation Martensitic (CLAM) steel exposed to oxygen-saturated, static or flowing (v ≈ 1.7-2.98 m/s) liquid LBE at 500 • C and 550 • C for 200-1500 h showed similar corrosion modes, but the weld was less resistant to erosion as compared to the base metal. Differences in the steel and weld oxidation behaviour may result from microstructural differences between welds and base metals, such as differences in grain size distribution and secondary precipitates.…”

“…Therefore, it is important to use an appropriate post-weld heat treatment to homogenise the weld microstructure [267]. For instance, tempering the weld of the CLAM steel at 760 • C for 1 h was found to effectively reduce the oxidation kinetics in contact with liquid LBE [265].…”