Annealing temperature effect on the pitting corrosion resistance of plasma arc welded joints of duplex stainless steel UNS S32304 in 1.0 M NaCl

Pitting corrosion resistance of 2304 duplex stainless steels after autogenous plasma-arc welding and subsequent short-time post-weld heat treatment at different temperatures, determined by critical pitting temperature in 1.0 M NaCl solution, has been investigated. The results showed that the as-welded joint displayed impaired pitting corrosion resistance and that pitting preferentially occurred at ferrite grain in heat-affected zone near the fusion line. Short-time annealing treatment at 1020-1120 degrees C has a beneficial effect on the pitting corrosion resistance of welded joint. The most favorable annealing temperature for the analyzed welded joints was found to be 1080 degrees C, at which the joint restored the pitting corrosion resistance lost during welding entirely. (C) 2011 Elsevier Ltd. All rights reserved.