Insufficient weld penetration at fabrication and assembly of pipe systems may often provide local geometric defects exposing various weld heat affected microstructures to possible crevice corrosion. For consistent evaluation of crevice corrosion performance of respective Duplex Stainless Steel welds quantitative online monitoring of crevice corrosion currents was carried out by application of a specific Remote Crevice Assembly (RCA). The tests were performed on a Duplex Stainless Steel in the as-delivered state and after various weld simulating heat treatments in different saline environments including formation waters and the standard NACE TM 0177 test solution, as well as at two different temperatures. For comparison, also a Super Duplex Stainless Steels was included however, only in the as-delivered heat treated condition. As a result, critical levels of NaCl and pH were identified for crevice corrosion at 25 and 50°C for both the Duplex (DSS) and the Super Duplex Stainless Steel (SDSS) in the as-delivered state, the SDSS revealing corrosion only at 50°C, however, with considerable repassivation effects. Crevice corrosion was characterised by primary dissolution of the austenite phase of the as-delivered microstructure. For the weld simulated DSS material crevice corrosion is initiated at precipitations of carbides, nitrides and sigma phase, leading to increased crevice corrosion currents depending on the amount of precipitations and being more pronounced after initial ferritisation. The ferritised heat affected zone of a weld will thus be more susceptible to crevice corrosion than the zones subjected to lower peak temperatures below A4 at welding. However, large heat inputs at multi-layer welding will provide opportunities for considerable precipitation and crevice corrosion also in such weld zones.