Welding Over Paint Primer
Abstract
When welding is performed over primer-coated steels such as in the shipbuilding and offshore structures fabrication industry, significant amounts of hydrogen and other gases, e.g., CO and Zn(v) are generated as the welding arc causes the primer to decompose. If entrapped in the weld pool, the hydrogen and other gases will produce porosity. Since hydrogen has been shown to compose most of the gas generated in a fluxcored arc weld over a primer-coated steel, it is also the most detrimental. According to the hydrogen-oxygen and }hydrogen-fluorine equilibrium considerations, an increase in the partial pressure of oxygen or fluorine could decrease the partial pressure of hydrogen within the welding arc. Consequently, a welding consumable that contains chemical ingredients of high oxygen and fluorine potential would be capable of minimizing hydrogen pick-up in the weld pool.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1998
- Accession Number
- ADA447591
Entities
People
- David L. Olson
- Kevin S. Johnson
- Stephen Liu
Organizations
- Colorado School of Mines