Influence of process parameters on the friction coefficient in one and multi phase steel strip drawing ironing test

Abstract

Part of the experimental results of influence on friction in the stripe ironing process with double thinning are presented in this paper. Applied was Schlosser model for evaluating influence of lateral force, contact pressure, average absolute roughness height and thinning strain on friction coefficient. Applied was classical model because of sufficient intensity of drawing and lateral force. If a lateral and drawing forces are small, classical model is not suitable and give unreal negative friction coefficient values. 20 mm wide and 2.5 mm thick strips of mild steel DC04 sheets were used in the single, three and four-phase process with a maximum thinning deformation of about 29%. Appropriate lubricant, mineral oil, was used in conditions of lower speed of 20 mm/min. Three and four phase process was realized with variable lateral force of 5, 10, 15 and 20 kN. The applied experimental test procedure enables the precise quantification of lateral force, contact pressure, thinning strain and roughness influence on friction to be established. Test also enables evaluation of lubricants quality.