A simple SCC specimen incorporating heat transfer with a crevice or deposits

A simple stress-corrosion cracking (SCC) specimen, suitable for slow strain rate testing and incorporating heat transfer, with an artificial crevice or deposits has been designed and tested. It appears that when the solute level is above a certain value it can concentrate. The kinetics of solute accumulation and the concentration that can be induced in the specimen have been determined. Build up of solute from the ppm level in the bulk environment to the level required to cause cracking can take hours, not days or years. The limiting concentration reached is controlled by thermodynamics, specifically the available superheat. A brief review of relevant literature suggests that this experimental approach to predicting SCC has significant advantages over a modelling or measurement approach. The specimen also lends itself to a monitoring role--a modern version of the Schroeder embrittlement detector.