Nanosecond pulsed laser welding of high carbon steels

•Nanosecond pulsed laser welding of 0.7% carbon steels is studied.•The role of pulse repetition rate, pulse duration, peak power and welding speed is assessed.•Sound weld beads were obtained with a maximum penetration depth as high as 230μm.•A feasibility area of the process is assessed.•The heat affected zone is almost absent and crack free sound beads were produced.

The present paper deals with the possibility to exploit low-cost, near infra-red, nanosecond pulsed laser sources in welding of high carbon content thin sheets. The exploitation of these very common sources allows to achieve sound weld beads with a good depth-to-width ratio and very small heat affected zones when the proper process parameters are involved. In particular the role of pulse frequency, pulse duration, peak power and welding speed on the characteristics of the weld beads is studied and the advantage of the application of short-pulse laser sources over traditional long-pulse or continuous wave one is assessed.