Abstract
This work investigates the metallurgical changes occurring during
welding of clad pipes. Welded samples with and without a Ni-interlayer
between the clad and base metal (BM) were investigated by light
optical microscope, electron microprobe analysis and microhardness
measurements. The investigations have focused on the microstructure
and properties of the clad and BM close to the weld, in addition to the
root and hotpass. The results indicate that the presence of a Niinterlayer
prevents carbon diffusion across the BM-clad interface
during exposure to elevated temperatures, thus preventing the
formation of a hard and crack susceptible microstructure.
welding of clad pipes. Welded samples with and without a Ni-interlayer
between the clad and base metal (BM) were investigated by light
optical microscope, electron microprobe analysis and microhardness
measurements. The investigations have focused on the microstructure
and properties of the clad and BM close to the weld, in addition to the
root and hotpass. The results indicate that the presence of a Niinterlayer
prevents carbon diffusion across the BM-clad interface
during exposure to elevated temperatures, thus preventing the
formation of a hard and crack susceptible microstructure.