Clading metal weld is a composite product developed to provide effective and economic utilization of expensive materials. The welding layer NiCu and NiFe that will be in contact with the corrosive media is made of the corrosion resistant alloys, whilst the less expensive base carbon steel covers the strength and toughness required to maintain the mechanical integrity. In a nuclear power plant clading metal weld joints are necessary for joining the different materials chosen for the various parts of the heat transfer circuit. Also Clading metal welds are utilized in processing pressure vessels, heat exchangers, tanks and storage facilities. Anodic polarization curves for deposited as weld and heat treated Ni alloy weld metal in 3.5% NaCl solution with alkaline pH are studying. Anodic polarization curve for NiFe weld metal on carbon steel heat treated for 50,500 and 1000 hr at 550 oC are recorded. The results indicated that, for example, the anodic polarization curve for NiFe weld metal heat treated for 500 hr at 550 oC in 3.5% NaCl solution, the corrosion current density was 11.23 μ A/cm 2 .The corrosion current density increase at constant rate which indicate a uniform corrosion. The hardness is 205Hv measured at 300 gmload.As for the anodic polarization curve for Ni-Cu weld metal heat treated for 500 hr at 550 °C tested in 3.5% NaCl solution, the corrosion current density was 28.42 µA/cm 2. The corrosion current density increases after that with constant rate till and of the experiment. The hardness is 235Hv measured at 300 gm load.

Dissimilar metal welding is frequently used to join carbon steels to other materials such as nickel metal. This approach is most often used where a transition in mechanical properties and/or performance in service are required. The power generation industry uses dissimilar metal welding extensively to reduce material costs and enhance performance in elevatedtemperature applications.Anodic polarization curves for deposited as weldcondition of Ni weld metal on carbon steel in 3.5% NaCl solution having neutral pH are studying. Anodic polarization curve for thermal aging of Ni weld metal for different agingtimes50,500 and 1000 hr at 550ºCare also recorded. The results indicated that the corrosion current of the Ni weld metal on carbon steel increases as aging time increase,also the grain size of the deposited Nickel increase during thermal aging for different times 50, 500 and 1000 hours respectively