VARIANCE ANALYSIS OF THE EFFECT OF FRICTION PARAMETERS ON THE FRICTION COEFFICIENT AND TOPOGRAPHY OF DC04 IN THE STRIP DRAWING TEST

<ns3:p>This article presents the results of a study examining the effect of contact pressure and sliding velocity on the coefficient of friction and the change in roughness of DC04 steel sheets used in the deep drawing process. The study was conducted using the strip drawing test method for three pressure and sliding velocity levels, both under dry friction conditions and with process oil lubrication. The coefficient of friction was determined based on the pulling and pressing forces as the average of three measurements, with a measurement uncertainty of no more than 1%. The obtained coefficient of friction values ranged from 0.115 to 0.173. Lubrication efficiency depended on sliding velocity, ranging from 4.4% to 15.5% for 3 mm/s, 5.3% to 11.6% for 6 mm/s, and 8.4% to 20.2% for 9 mm/s. Analysis of variance and regression models were used to analyze the results, with coefficients of determination (R) of 0.8300 for the friction coefficient and 0.5751 for the Sa parameter. All analyzed factors significantly influenced the friction coefficient, while the effect of sliding velocity on the Sa parameter proved to be statistically insignificant. It was found that with increasing sliding velocity, the friction coefficient decreased, while increasing contact pressure reduced the surface roughness of the samples after friction.</ns3:p>