Effect of yttrium addition on microstructure, mechanical and corrosion properties of 20Cr13 martensitic stainless steel

The effects of rare-earth yttrium (Y) element on the microstructure, mechanical properties and corrosion properties of 20Cr13 martensitic stainless steel were investigated by optical microscopy, scanning electron microscopy and tensile test. Electrochemical experiments were carried out to study the effect of rare-earth element Y addition on corrosion resistance. The results showed that the addition of 0.02 wt.% rare-earth yttrium to martensitic stainless steel could affect the microstructure transformation, and Ac3 temperature was obviously increased. In the stainless steel after heat treatment, there were more pro-eutectoid ferrite in the steel with 0.02 wt.% yttrium. The mechanical test results showed that the addition of 0.02 wt.% yttrium could significantly improve the tensile strength and elongation of the steel, which was related to the influence of yttrium element on inclusions in the test steel. With the quenching temperature of 0.02 wt.% yttrium steel increasing, the content of the ferrite in steel was affected and the corrosion resistance was remarkably improved.