High joint completion rate welding methods for sheet material can offer cost reduction for mass production applications, relative to more conventional arc processes. Study was carried out of joints made in UNS S32304 duplex steel sheets by laser and resistance welding, comparison being made with gas-shielded arc welds. Metallography and mechanical tests were carried out, while corrosion resistance was determined by short term ferric chloride testing and long term exposure to dilute sodium chloride solutions.

Weld area ferrite levels ranged from 45–99%. Transverse tensile strengths exceeded the specified minimum parent material level. For the welds made, pitting temperatures in 6%FeCl₃ were above 5°C, while no attack was found in 200ppm NaCl solution at 65°C despite high weldment ferrite levels. In both short and long term tests, predominantly ferritic fusion boundary regions showed sensitivity to pitting.

Overall, it was concluded that the use of laser and resistance welding is viable for UNS S32304 sheet material for service in mildly corrosive media. High nitrogen material is preferred to promote austenite reformation at welds.