Corrosion is one of the causes of deterioration of a metal material, the process of degradation / deteorisation. Some environmental conditions can accelerate the corrosion of metal materials such as sea water. Sea water containing NaCl can accelerate the corrosion. Testing done by preparing specimens that have been measured and weighed in advance and will be dyed and steamed in a water solution of the Sea, 10% NaCl, NaCl 20% and 30% NaCl. There are eight specimens in doing welding with SMAW welding current 80 A and 8 specimens that did not do the welding results showed that the corrosion rate of the highest value found in SMAW welding specimens made and steamed above the 20% NaCl solution with the corrosion rate of 0.002066 MPY.