Again, these weld crater shrinkage cavities are a naturally occurring phenomenon found in arc welding. While they can occur with all arc welding processes, they are more prevalent with processes that are capable of higher deposition rates and producing larger weld puddles (i.e.. welds with a greater volume of liquid metal). In addition, they are more pronounced when welding with a vertical up progression, as the effect of gravity tends to enhance the size of the pipes. Finally, the piping effect will vary, depending on the type of weld metal.
Crater shrinkage cavities occur with all brands or all manufacturers’ welding electrodes. Figure 4 shows examples of this shrinkage cavities in welds made with four different brands of stainless steel flux-cored gas-shielded wires.