Diffusion bonding experiments of 316L steels in a Gleeble 3800 thermomechanical simulator for investigation of non-destructive inspection methods

•Diffusion bonding experiments and heat affected zone tests of 316 L in a Gleeble 3800 thermomechanical simulator were carried out.•A new method reveals the surface contact electrical resistance through diffusion bonding by numerical simulation.•Significant contact electrical resistance at diffusion bonding seam which effected in axial creep. One can estimate the status of the bonded seam. Diffusion bonding methods are one of the joining methods for Plasma Facing Components in fusion reactors like ITER or in later decades the DEMO reactor. Diffusion bonding of 316 L specimens were investigated on the Gleeble 3800 thermomechanical physical simulator at University of Dunaújváros at 1000–1050 °C, with 20−30 MPa, through 40−80 min under high vacuum conditions. A new method was found that reveals the surface contact electrical resistance through diffusion bonding by numerical simulation. Physical simulation on Gleeble of diffusion bonded samples and heat effected zone tests were carried out with the same parameters, but the axial creep deformations were different in the pairs. The numerical simulations showed a significant contact electrical resistance at diffusion bonding seam which effected this different in the axial creep. In this way, through numerical simulations of a Gleeble diffusion bonding process the contact electrical resistance could be estimated in a non-destructive way, and one can estimate better the actual status of the bonded seam during the joining process. The work intended to prepare samples for further non-destructive tests as well.