Product Code: ICA12_1501

Narrow Gap Laser Welding of Thick Section Stainless Steel
Authors:
Ahmed S. Elmesalamy, Laser Processing Research Centre, School of Mechanical, Aerospace and Civil Engineering, The Manchester Univ.; Manchester Great Britain
Lin Li, Laser Processing Research Centre, School of Mechanical, Aerospace and Civil Engineering, The Manchester Univ.; Manchester Great Britain
John A. Francis, Laser Processing Research Centre, School of Mechanical, Aerospace and Civil Engineering, The Manchester Univ.; Manchester Great Britain
Presented at ICALEO 2012

Laser welding of thick cross section stainless steel normally requires high power lasers. Typical weld penetration depth is 1-2 mm/ kW laser power. Arc welding is commonly used for thick section stainless steel welding of nuclear power plant components. Arc welding requires high number of passes, leading to high heat input to the material. This increases the tendency for distortion, high residual stress inside the weld cross section and can lead to the increase in the segregation of important alloying elements that may decrease the corrosion resistance. This work investigates combined laser and arc welding technique. Laser welding is used for welding the mid section of the sample. Arc welding is used for joining the outer sections from both sides. Experiments were carried out using a 1 kW fibre laser and a TIG welder. The main objective is to achieve sound weld for thick cross section with combined welding technique using limited laser power and minimum number of filling passes of arc TIG welding. Material distortion, tensile strength and residual stress, microstructure and stress corrosion characteristics are studied and compared with the TIG arc welding technique.