Effect of a brief post-weld heat treatment on the microstructure evolution and pitting corrosion of laser beam welded UNS S31803 duplex stainless steel

The effect of laser-beam welding and subsequent short-time post-weld heat treatment at different temperatures and holding time on microstructure evolution and pitting corrosion behavior of UNS 531803 duplex stainless steel was investigated. The results showed the as-welded joint displayed impaired pitting corrosion resistance and that pitting preferentially occurred at ferrite grain in the fusion zone. Short-time heat treatment enhanced the pitting corrosion resistance of welded joint. Optimal post-weld heat treatment of 3 min heat treatment at 1080 degrees C was identified at which the joint restored the pitting corrosion resistance lost during welding process. (C) 2012 Elsevier Ltd. All rights reserved.