Abstract
It was found that Fe-Al alloy layers were formed on the surfaces of steel specimens, when the specimens were dipped in molten lead bath containing a liquid solution of 0.12-0.5 wt% Al at 650-900°C for 5-60min.
The thickness of the alloy layer increased with the increase of aluminum content of the lead bath and with the rise of bath temperature.
The weight loss of steel specimens during dipping in a lead bath was much less than that dipped in an aluminum bath.
Metallographic observation and X-ray microanalysis revealed that the alloy layer formed in the lead-aluminum bath was composed of two layers as that formed in the aluminum bath. The layer adjacent to the steel was assumed to be Fe2Al5 and the outer layer was to be FeAl3.
A uniform cover of Fe-Al alloy layer was observed on the surface of the steel specimens when they were dipped in Pb-20 wt% Sn bath containing aluminum at a relatively low temperature of 600°C as that observed by dipping in a lead bath at 700°C.
