Formation of graded structures under nigh-temperature oxidation conditionswith surface light-heat treatment

Complex alloying of low-carbon steel with treatment by artificial concentra ted solar radiation (CSR) in air using a LaB6-based composite is studied. T he distribution of elements through the thickness of the alloyed layer alon g the axis of CSR entry and at the periphery of the working zone is establi shed. On the basis of electron-probe microanalysis, x-radiographic. and met allographic data it is established that as a result of high-temperature oxi dation of the composite, formation of new phases, and convective mass trans fer under CSR conditions, a graded structure forms at the steel surface in the form of a dense three-layer oxide film. Its outer layer contains lantha num and nickel chromites that provide high resistance to marine corrosion.