Effect of Antirust Oil on Corrosion Behavior of DP590 Steel

DP590 steel was painted with different amount of antirust oil. The microstructur of DP590 steel was observed by transmission electron microscope (TEM). The effects of painting amount of antirust oil on surface wettability and corrosion resistance of DP590 steel were studied by contact angle measuring instrument, scanning electron microscope (SEM) and salt spray corrosion test. The results show that the microstructure of DP590 steel was composed of coarse ferrite and a little martensite. The lath martensite interpenetrated in the ferrite and was interlaced with ferrite to form a similar fibrous dual-phase mixed structure. The corrosion pits on DP590 steel surface were small pits induced by inclusion and large ulcerated pits formed by galvanic corrosion between martensite phase and ferrite phase. With the increase of antirust oil amount, the surface contact angle of DP590 steel first increased, then decreased and then increased. The antirust oil had a strong protective effect on the surface of DP590 steel in a short time. Painting DP590 steel with 800 mg/m² antirust oil could not only get the best protective effect, but also save the coating cost of antirust oil.