THE SEGREGATION AND SURFACEENRICHMENT OF ARSENIC AND PHOSPHORUS IN EARLY IRON ARTIFACTS

Previous work on iron‐arsenic alloys has shown that considerable superficial arsenic enrichment occurs during oxidation at high temperatures. This process is very likely to be the explanation for the layers of high arsenic concentration that have been observed in the microstructure of early iron artifacts by many workers. Experiments have been made to determine how far the alternative theory of the use of Fe‐As alloys as joining media could be responsible. It has been shown that Fe‐As alloys can in some cases facilitate joining but that when they do the resulting joint is embrittled. When the arsenic concentration is reduced sufficiently to avoid this there is then no advantage over the normal hammer welding without an arsenic interlayer. Similar experiments have been carried out with phosphorus and similar conclusions have been drawn.