METHOD FOR HEAT TREATMENT OF DRAWN ARTICLES AND INSTALLATION FOR PERFORMING THE SAME Russian patent published in 1998 - IPC

FIELD: hardware production, namely wire production. SUBSTANCE: method comprises steps of heating blank until austenization temperature, isothermically soaking it in protective medium, intensively cooling it until structure stabilization temperature; finally cooling until environment temperature. Novelty is isothermic soaking in protective medium realized after intensive cooling performed step-by-step in flow of cooling liquid. After each cooling step temperature of article is measured and according said temperature cooling rate of next cooling step is controlled in such a way that temperature of article after last cooling step is equal to temperature of predetermined isothermic soaking. Said intensive cooling is performed in flow of water base cooling liquid. Rate of intensive cooling is controlled due to changing length of cooled portions of article. Installation for continuous treatment of drawn articles of steel and alloys includes arranged successively: uncoiling apparatus, heating furnace, cooling chamber in the form of alternating sections for liquid and air cooling, apparatus for isothermic soaking with temperature pickups, bath for cooling and washing out, coiling apparatus. Said installation is also provided with temperature pickups mounted in each section for air cooling, actuating mechanisms for controlling liquid supply connected with each air cooling section, control unit whose inputs are connected with temperature pickups, outputs-with actuating mechanisms for controlling liquid supply. Apparatus for isothermic soaking is in the form of chamber with protective medium, each section for liquid cooling has two parts. One of said parts is designed for stable cooling, another - for controlled cooling. EFFECT: enhanced accuracy of achieving phase conversion temperature at predetermined cooling rate and therefore high degree of structure uniformness along the whole length of article, enhanced physicomechanical characteristics and quality of articles, minimized loss of yield. 5 cl, 3 dwg, 5 expa