Element Migration and Diffusion at the Bonding Interface of the Bimetallic Composite Billet Produced by the ESRC Method

摘要

A bimetallic GCr15/45 carbon steel has been produced by the newly developed electroslag remelting cladding (ESRC) technique. Based on the solidified precipitates characteristics of the bimetallic materials and the relationship of temperature varying with time at the bimetallic interface during the ESRC process, the one-phase model in DICTRA was selected to calculate the element diffusion behavior at the bimetallic interface in the present study. The calculated result illustrates that the diffusion distance of C (3720 lm) is much larger than that of Cr (42 lm), Si (30 lm), and Mn (34 lm) due to the small atomic size, while the experimental result of the bimetallic interface shows that the transition width of Cr is 1140 lm which is much larger than that of the calculated values by diffusion model. The difference between the above calculated and experimental results illustrates that a fusion bonding with obvious element migration has occurred between the bimetallic metals in addition to the diffusion bonding. Affected by the element migration and diffusion, a good metallurgical bonding with no defects is formed between the bimetallic materials and the microstructure as well as the corresponding properties at the interface change significantly.

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