Microstructure and Pitting Corrosion Resistance of Titanizing Coating Prepared by Pack Cementation on 316L Stainless Steel

Titanizing coatings were prepared on 316L stainless steel by the pack cementation method at 950, 1020 and 1100 degrees C. The coating surface and cross-section were analyzed by using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrochemical corrosion behavior in 3.5% NaCl solution at 80 degrees C was measured through electrochemical techniques. The results showed that titanium coatings were continuously generated on the 316L substrate at different treatment temperatures. The coatings were composed of NiTi2, FeTi, NiTi, Ti and delta-ferrite phases through the diffusion process. The titanium coatings displayed much higher polarization resistance and pitting resistance than 316L stainless steel in the hot seawater. The pitting potential reached approximately 950 mV(SCE) with an increase in the titanization temperature from 950 to 1100 degrees C.

Automated summary

The study on the titanium coatings prepared on 316L stainless steel by the pack cementation method at different temperatures shows that with the increase in temperature, the corrosion resistance of the coatings also improves, displaying higher corrosion resistance and pitting resistance, with the pitting potential reaching approximately 950 mV(SCE) as the titanization temperature increases from 950 to 1100 degrees C.