Cause and repair method of corrosion pits on ABS Grade B marine steel plate

ABS Grade B marine steel plates are almost entirely used in the shipbuilding industry for the construction of structural parts for ships, barges and ship equipment.

Corrosion pits sometimes occur on the surface of ABS Grade B marine steel plate. The depth is mainly concentrated in the 0.1-0.3mm range, and the deep pit reaches 0.5mm.

The corrosion defect of ABS Grade B marine steel plate is caused by pitting corrosion or crevice corrosion on the surface of ABS Grade B steel which is stored in coastal atmosphere for a long time. The presence of Cl in the oxide scale and Cl deposited in the environment promote the corrosion of ABS Grade B marine steel plate.

Shipyard usually adopts repair method for slight corrosion defects of ABS Grade B marine steel plate. For serious corrosion defects of ABS Grade B steel, shipyard usually adopts spot welding and post grinding.