Factors responsible for cracking and their control

The interaction between the factors responsible for cracking and the ways in which control over them may be achieved can now be discussed. 

1 Moisture in the coating of manual metal-arc electrodes, in the flux used in submerged-arc welding or in flux-cored wires. 

dirt and grease either on the surface or trapped in the surface layers of welding wires. 

4 Hydrated oxide, e.g. rust, on the surface of welding wires. 

The principal sources of hydrogen from the material to be welded are  

---