Abstract
Pitting resistance was evaluated in autogenous GTA welds of approximately 30 commercial and laboratory heats of AISI 316 steel sheets by the standard ferric chloride immersion test and the potentiodynamic anodic polarization test in acid chloride solution. The results indicate that the solidification mode, although it affects the segregation intensity, has only a secondary influence on pitting resistance in this type of weld. The last interdendritic regions to solidify in primary austenitic welds and the delta ferrite/austenite phase interfaces in primary ferritic welds are the most susceptible sites for pit initiation. Increasing the sulfur content will reduce the pitting potential and increase the pit density in the ferric chloride immersion test, but it has no effect on pit growth rate. The effects of reducing the phosphorus or manganese content are also discussed.
