Microstructure and Properties of Hot Roll Bonding Layer of Dissimilar Metals (2)

摘要

The hot roll bonding of zirconium and stainless steel inserted with tantalum was investigated using the newly developed rolling mill. The effect of hot rolling temperatures of zirconium/stainless steel joints on bonding interface structure was evaluated. Intermetallic compound layer containing cracks was observed at the bonding interface between stainless steel and tantalum when the rolling temperature was above 1373K. the hardness of the bonding layer of zirconium and tantalum bonded above 1273K was higher than tantalum or zirconium base metal in spite of absence of intermetallic compound. The growth of reaction layer at the stainless steel and tantalum interface and at the tantalum and zirconium interface was conforming a parabolic low when that was isothermally heated after hot roll bonding, and the growth rate was almost same as that of static diffusion bonding without using hot roll bonding process. It is estimated that the strain caused by hot roll bonding gives no effect on the growth of reaction layer. It was confirmed that the dissimilar joint of zirconium and stainless steel with insert of tantalum having the sound bonding the newly developed hot roll bonding process.