Titanium is a metal with strong passivation tendency. A stable oxidation protective film can be quickly formed in air and oxidizing or neutral aqueous solution, even if the film is damaged for some reasons, it can be quickly and automatically restored. Therefore, titanium has excellent corrosion resistance in oxidizing and neutral media. M390 is too expensive, easy to rust after a long time, and its corrosion resistance is slightly poor.
M390 die steel is a kind of high chromium Martin loose iron corrosion resistant steel. Its metallographic structure is a large number of chromium carbide and vanadium carbide particles, which are evenly distributed on the substrate with Cr> in 12%. Its advantages are high corrosion resistance, high wear resistance and good polishing and optical rotation.