Influences of the heat treatment on properties of the electroless Ni-P-B coating on the hydraulic upright post

Ni-P-B alloy is deposited on the hydraulic upright post by the method of electroless plating to improve its hardness and corrosion resistance and the influences of the heat treatment on the plating structure and properties are studied.The results show that its microhardness increases from HV468.7 to HV 1637.2 when the plated alloy changes from the amorphous state to the crystalline state after the heat treatment at 450℃ for half an hour;its corrosion rate decreases from 2.2682 mm/a and 0.4410 mm/a to 0.6172 mm/a and 0.00783 mm/a respectively in the NaOH solution (100 g/L) and the analog mine condition;in 10% HCl solution,its corrosion rate gets faster,from 5.4589 mm/a up to 28.044 mm/a.