| The effects of cold work, oxygen availability, and specimen preparation on the oxidation phenomena of low carbon steel have been investigated at temperatures in the range 20-200{dollar}spcirc{dollar}C, with ellipsometry, to obtain a better understanding of the superior break-in behavior of soft steel over hard steel in lubricated sliding.; Results show that oxidation rates are affected by cold work also at temperatures below 200{dollar}spcirc{dollar}C, a temperature above which much work had already been published. Cold-worked steel shows higher oxide growth rate than does annealed steel at temperatures as low as 130{dollar}spcirc{dollar}C and the effect increases with temperature. Nevertheless, oxide film types and their growth pattern were the same for both annealed and cold-worked steel. Oxidation rates are affected when oxygen availability is very limited; oxidation in dry air and oxidation in nitrogen with 1% oxygen show no differences in oxidation rates, in contrast, oxidation in nitrogen with 3ppm oxygen shows slower oxidation rates. Surface preparation of specimens affects oxidation phenomena: both hydrogen treatment and polishing with alumina powder greatly reduce oxidation rate. |
