Abstract
The aim of this investigation was to determine whether the composition of a shielded-metal arc-welding electrode coating affected the low-temperature impact toughness of austenitic stainless-steel weld metal. It is generally accepted that increases in the δ-ferrite and nitrogen contents result in a decrease in toughness at low temperatures. Weld metal from electrodes with a basic coating also generally exhibit better toughness than those from rutile (acidic) electrodes. An increase in basicity was expected to decrease the number and size of inclusions, which in turn provides a tougher weld metal. Three commonly available potassium-rutile E308L electrodes were used, complying with the E308L-16 and E308L-17 specifications. Analysis of the electrode coatings showed very similar chemistry and basicity. Significant differences in the inclusion contents of the weld metals were observed: the E308L-17 weld metal had a lower inclusion content (1.4% by volume) than the E308L-16 weld metal (3.7%). The former had higher impact toughness at all temperatures, despite a slightly higher nitrogen content. Regression analysis confirmed that the inclusion content had a significant effect on the impact toughness at all temperatures.
Original language | English |
---|---|
Pages (from-to) | 323-330 |
Number of pages | 8 |
Journal | Journal of the Southern African Institute of Mining and Metallurgy |
Volume | 122 |
Issue number | 7 |
DOIs | |
Publication status | Published - 1 Jul 2022 |
Keywords
- Shielded-metal arc welding
- austenitic stainless steel
- ferrite number
- flux composition
- inclusions