Solid Cadmium Embrittlement: Steel Alloys

The phenomenon, solid cadmium embrittlement (described in Solid Cadmium Embrittlement: Titanium Alloys, Corrosion, 26, 409 (1969) October), has been found to occur in the steel alloys 4340 and 4340M. The temperature dependence, i.e., increasing crack propagation rate with increasing temperature, was found to be the same as for the titanium alloys. The material strength level was varied in the 4340 alloy, showing a significant effect. Below the 200 ksi ultimate strength level, no cracking was observed, while above this strength level, significant cracking was observed. Results in this investigation support the earlier contention that cadmium surface diffusion is the rate controlling step in the phenomenon.