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 provide d evidence that the relationship between the aging time and corrosion rate is not linear. A series of metallographic studies was performed to survey t his phenomenon.