Quenching and tempering HB220-270, nitriding HRC>65 foreign useful titanium carbide coating method to improve the corrosion resistance of the screw surface, but reported that its wear resistance is not good enough. Foreign countries have taken a series of measures to improve the wear and corrosion resistance of the screw.
One approach is to use highly wear-resistant and corrosion-resistant alloy steel. Such as 34CrAlNi, 31CrMo12 and so on. There is also a method of spraying Xaloy alloy on the surface of the screw. This Xaloy alloy has high wear and corrosion resistance.