Formation of nanocrystalline during flash welding of 0Cr16Ni22Mo2Ti steel

A nanocrystalline layer was fabricated in bond area of 0Cr16Ni22Mo2Ti austenite steel using flash welding. The mean grain size near bond line is about 20 nm, and the farther the distance from bond line, the larger the size of the nanocrystalline. The thickness of the nanocrystalline layer is about 50 -m. The formation mechanism of the nanocry- stalline may be that the metal in semisolid state is deformed severely and its solid grains are fragmented.