Abstract :
EN 1.4410 (UNS S32750) superduplex stainless
steel (SDSS) with a thickness of 6.5 mm has been
welded by plasma arc welding (PAW) process with different
heat inputs. To determine the mechanical properties,
impact toughness testing at subzero temperatures starting
from -20 C down to -60 C was carried out while
fractographs were examined by scanning electron microscopy
(SEM). Microstructural examination included macroand
microphotographs of the cross sections, ferrite content
measurements and hardness survey of the weld zones.
Interpreting all data obtained, results were compared
depending on the heat inputs of the joints while the relation
between heat input and properties was explained. Promising
low temperature toughness, results were obtained while
it was concluded that the variation of the heat input influenced
mainly the ferrite content and hardness of the weld
zones. Results showed that PAW, which is considered
immature process in welding of SDSS, can be employed
for 1.4410 superduplex grade with controlled heat input so
the properties.
