Tuning the pitting performance of a Cr-13 type martensitic stainless steel by tempering time

The microstructural evolution and pitting performance of a Cr-13 type martensitic stainless (MSS) undergone tempering at 500 ? for different time are investigated via electron microscopies and electrochemical measurements. The precipitation sequence of carbides in MSSs tempered for 0.5-48 h is theta-M3C -> 10 nm sized M23C6 -> 100 nm sized M23C6. Severe corrosion occurred when the MSS were tempered within the time window of 2-24 h. In contrast, the passivation of MSSs was recovered as the tempering time increased to 48 h or longer. Our finding in this work provides a new path for optimizing the corrosion resistance of MSSs via tempering time.

Automated summary

The microstructural evolution and pitting performance of Cr-13 type martensitic stainless steel tempered at 500°C for different times were studied. Severe corrosion was observed when tempering was done within 2-24 hours, while passivation was recovered when tempering time was increased to 48 hours or longer. The research provides a new approach to optimizing the corrosion resistance of martensitic stainless steels through tempering time.