Submerged arc welding of stainless steel and the challenge from the laser welding process

摘要

The welding of austenitic and duplex stainless steels has been reassessed by questioning traditional requirements of the weld metal and/or the heat affected zone (HAZ). The use of high dilution submerged arc welding of austenitic and duplex stainless steels has been shown to produce acceptable properties, despite the high heat input used in some instances. Corrosion characteristics have been established as being acceptable too. These findings have been further validated by examination of the weld region material using thin foil transmission electron microscopy (TEM). This showed that while some intermetallic phases were present, they did not adversely affect the weld metal properties. In addition, an examination has taken place of Nd:YAG laser-welded austenitic and duplex stainless steels, to establish the potential viability of this route compared to the submerged arc welding process. The material properties, including the relevant corrosion testing, have been found to be acceptable. TEM has again shown that some intermetallic phases are present in the weld metal. It has been suggested that a segregation mechanism is responsible for their presence in this case.