Underwater explosive welding of tungsten to reduced-activation ferritic steel F82H

• The underwater explosive welding was successfully applied in the joining of tungsten to F82H reduced activation ferritic steel.
• Microstructure of the interface showed the formation of a wave-like interface with a thin mixed layer of tungsten and F82H.
• Nanoindentation hardness results exhibited a gradual change away from the welded interface without hardened layer.
• Small punch tests on the welded specimens resulted in the cracking at a center of tungsten followed by the interfacial cracking.

The present study reports the underwater explosive welding of commercially pure tungsten onto the surface of a reduced-activation ferritic steel F82H plate. Cross-sectional observation revealed the formation of a wave-like interface, consisting of a thin mixed layer of W and F82H. The results of nanoindentation hardness testing identified a gradual progressive change in the interface, with no hardened or brittle layer being observed. Small punch tests on the welded specimens resulted in cracking at the center of the tungsten, followed by crack propagation toward both the tungsten surface and the tungsten/steel interface.