Corrosion of 20khl3 steel in lead melts saturated with oxygen

We study the high-temperature interaction (650 deg C, 500 h) of 20Kh 13 chromium steel with melts of stagnant lead saturated with oxygen (C(O)approx 6 x 0.001 wt.%). First (up to 200 h), separate islands of Me,'04 oxides (Me: Fe, Cr, Pb) are formed on the steel surface. In the course of time (for 500 h), these islands completely cover the steel surface as a result of lateral growth. The upper part of the oxide layer is formed by the (Fe(1-x)Pb(x))O Fe2O3 complex oxide growing from the initial "solid-metal-melt" interface toward the liquid-metal medium. The inner part of the oxide layer is spinel (Fe(1-x)Pb(x))O((Fe(1-x)Cr(x))2O3] enriched with chromium and formed on the basis of the matrix. Both layers symmetrically grow with respect to the initial "solid-metal-melt" interface. Lead does not penetrate into the steel matrix and is fixed only in the oxide layer.