THE DEPOSITION OF CORROSION PRODUCTS IN PB-17LI

A series of simple deposition tests has been carried out in Pb-17Li co ntained in type 316 stainless steel tubes under a temperature gradient . Two basic types of deposit have been identified from all 316 steel s ystems. The first type which is dendritic in form is composed mainly o f iron and chromium and deposits in the temperature region 673 to 823 K. Deposits at the lower temperature were chromium rich whilst those a t the higher temperature were iron-rich. The second type found at temp eratures below 623 K shows a temperature dependence being composed of nickel and manganese at 573 K and nickel, iron and chromium at 623 K. Pure nickel only deposits if the alloy is at near saturation in nickel at the highest temperature of the system (873 K). Aluminium mass tran sfers readily in Pb-17Li and in solution causes the formation of alumi nide layers on the steel surface in the high temperature zone.