Porosity in weld metal refers to the cavity-type discontinuities formed by gas entrapment during solidi- fication. It is one of the most common de- fects of the self-shielded, flux cored arc welding (FCAW-S) process. In the pre- sent study, the causes and influence fac- tors of pore formation in welds made by a self-shielded, flux cored electrode were investigated. The results of this study re- vealed nitrogen content is not the only main influence factor in the formation of porosity in welds made by an FCAW-S electrode; oxygen can also rapidly in- crease the number of pores in such welds. It was found aluminum and rare earths (RE) effectively reduce the pore sensitiv- ity of welds. Of the two materials, alu- minum has a stronger ability of reducing nitrogen than RE. Both aluminum and RE significantly reduce oxygen content in the weld.

A Study of Weld Pore Sensitivity of Self-Shielded, Flux Cored Electrodes An investigation revealed both nitrogen and oxygen content can affect the formation of porosity in welds made using FCA W-S electrodes

R. Yeo

Papers

It's quicker by tube : welding with self-shielded cored wires