The effect of aging on the intergranular corrosion of a 24Cr-14Ni-0.7Si stainless steel for welding in architecture

Stainless steel with high Cr (24 %) and Ni (14 %) contents is becoming more important for use as core material for welding wires and in burning ovens due to its excellent corrosion resistance. This 24Cr-14Ni material, with a Cr enriched sigma -phase, can be formed in a temperature range between 600 - 950 degreesC. In contrast, the remaining matrix phase can be induced into a Cr-depletion after the sigma -phase formation. This research studied the intergranular corrosion rate under aging temperatures that are similar to the service parameters of this material in burning ovens. The study provided evidence that the relationship between the aging time and corrosion rate is not linear. A series of metallographic studies was performed to survey this phenomenon.