Effects of Nitrogen and Molybdenum on Weld Solidification Crack Susceptibility

Weld Crack Susceptibility of Duplex Stainless Steel (Report VI)

Abstract

Weld solidification crack susceptibility and pitting corrosion resistance of tentative duplex stainless steels were investigated in order to decrease the crack susceptibility without decreasing the corrosion resistance in a duplex stainless steel. The results obtained are as follows:
(1) Crack susceptibility was improved with decreasing the N content in 22 to 25Cr-1 to 10Ni duplex stainless steels, but was not considerably changed with increasing the Mo content up to 4.5% at constant level of 0.03%N.
(2) Corrosion resistance was improved with increasing the Mo content at constant level of 0.03%N.
As a result, it was suggested that a lower N and Mo in the range of 4.0 to 4.5% were very effective for the development of a duplex stainless steel which had the low crack susceptibility without decreasing the corrosion resistance.