Application of Hydrothermal Treatment on BF Slag and Waste Glass for Preparing Lubricant Materials in High Strain Rolling for Ultrafine-grained Steel Production

In order to establish a high strain rolling process for the production of ultrafine-grained steels, a new lubricant showing stable biting between rolls and workpieces as well as a lubricating effect inside the hot rolls is required. We focused on glass materials for the stable biting property in view of their hardness and investigated the possibility of applying blast furnace (BF) slag and waste glass as the lubricant. The addition of a lubricating property to these glass materials was attempted by water introduction with a hydrothermal treatment, using the water release with heating that leads to a structural change inside the hot rolls. For that purpose, the hydrothermal treatment of the BF slag and waste glass was carried out, and the water release with re-heating was investigated. Furthermore, friction properties of the synthesized lubricants containing the hydrothermally treated materials were measured by a Timken extreme pressure tester at 373–1173 K.