Effects of Chromium Content on Mechanical Properties and Corrosion Resistance of 00Cr25Ni7Mo3N Duplex Stainless Steel

The effects of chromium content (23.87wt%-25.52wt%) on microstructure, mechanical properties and corrosion resistance of 00Cr25Ni7Mo3N duplex stainless steel were studied using optical microscopy, universal testing machine and corrosion test system. The results show that with the increase of the chromium content, the ferrite content in the experimental steel increased while the austenite content decreased. The volume ratio of the two phases reached close to 1∶1 in the experimental steel with the chromium content around 25.5wt%. When the chromium content increased from 23.87wt% to 25.52wt%, the yield strength and tensile strength were improved by 57.5 MPa and 27.5 MPa respectively and the impact energy decreased by 31.7 J. But the effect of chromium content on the plasticity was little. With the increase of chromium content, the pitting corrosion mass loss of the experimental steel decreased obviously, and the intergranular corrosion resistance was improved.