Fundamental and applied experimental investigations of corrosion of steel by LBE under controlled conditions: kinetics, chemistry, morphology, and surface preparation

An innovative research program is proposed to investigate the corrosion of steel by lead alloys, and in particular lead-bismuth eutectic (LBE). In our previous work, some steels were found to be far more resistant to corrosion by LBE than others depending on surface preparation (cold working). This program would allow testing of crucial hypotheses about the causes of the observed increased corrosion resistance. We propose to build a new test facility at UNLV to expose steel samples to LBE as well as facilities to prepare steel samples as indicated by our work. The unique capabilities of the test system will make investigations of the fundamentals of lead alloy corrosion under a variety of conditions feasible and lead to the establishment of new protocols for the minimization of molten lead alloy corrosion of structural materials. These capabilities include fast and controlled sample introduction via a vacuum load lock system, both high temperature operation and controlled chemical environment by the use of alumina and silica or other refractory materials for lead alloy containment, and highly modifiable flow systems for determination of fundamental kinetics and parameters and thus accurate modeling of lead alloy systems. In parallel with the test effort we will prepare well characterized samples of candidate materials and model systems. In particular we shall look at modifications of the sample surface and near surface composition (e.g. the effects of cold working). In addition we shall investigate the feasibility of using the mass selected ion facility at UNLV developed by Prof. Farley to both modify surface composition (e.g. ion implant oxygen to compensate for oxygen deficiencies) of test samples and to introduce stable isotope labels into known steels to determine mass transport properties inside the steels