Effect of Surface Metal Modification on Corrosion Resistance of Ships
Different compound metal powder was coated on the surface of 20 steel for ships by the method of supersonic plasma spraying to obtain surface metal modification, the salt-spray corrosion resistance, electrochemistry corrosion resistance and immersion corrosion resistance in man-made acid rain were tested and analyzed. The results show that the surface metal modification by spraying compound metal powder can effectively improve the corrosion resistance of 20 steel for ships, and the effect is especially obvious with the addition of Sc in the compound of metal powder. Compared with the sample without surface metal modification, the compound of metal powder containing Sc sprayed on the surface of 20 steel for ships by supersonic plasma spraying makes the mass loss rate of the sample after salt-spray corrosion for 240 h decreased by 87%, makes corrosion potential in 6 mol/L KOH solution shuffled by 13.64%, and makes the corrosion rate in man-made acid solution decreased by 91.3%.