COMPOSITION AND STRUCTURE OF SCALE OF IRON-CHROMIUM-NICKEL ALLOYS BEFORE AND AFTER CYCLIC SURFACE HEATING IN VACUUM

The authors studied the scales formed in vacuum (p less than or equal to 10(-2) Pa) on Grade 03X20H45MM4BCh, 04X16H11M3T, and 05X12H2M steel s with the cyclic action thereon of a flux of 8-kV electrons both theo retically (on the basis of thermodynamic and crystal-chemistry premise s) and experimentally (employing X-ray photoelectron and Auger electro n spectroscopies). They conclude that a single-layer spinel of varying composition Fe3-x-yCrxTiyO4 forms on the studied steels. The spinel-f orming phase on the studied steels in their low-temperature oxidation in air is Fe3-xCrxO4. The authors show how to calculate the compositio n and lattice constant of the spinels.