Abstract / Description
This paper studies the effect of welding heat input on microstructure and low-temperature toughness of laser-arc hybrid welded (LAHW) SAF2507 super-duplex stainless-steel (SDSS) joints. Heat input was adjusted from 0.204 to 0.407 kJ/mm by changing the welding speed. Results indicate that low heat input brings high ferrite content and low impact toughness. The medium heat input generates a balanced two-phase microstructure and gains the highest impact energy of 36.0 J at −46 °C. Excessively high heat input results in obvious grain coarsening and degraded impact performance. This study offers an experimental basis and parameter reference for practical welding production.