METHOD OF ASSESSMENT OF FORCE AND FRICTION COEFFICIENT DURING COLD METAL FORMING AND DEVICE FOR ITS IMPLEMENTATION

摘要

FIELD: metallurgy.;SUBSTANCE: method of assessment of friction parameters during cold metal forming is formed, which consists in stretching through rolls with the pre-set crimping of samples with a conic section from one end, the length of which allows to increase the level of crimping at stretching out of samples, visually identify a place of formation of scores on samples, drawing for all samples of the diagram “deformation force” vs. “distance”, due to which for the place of scores formation the crimping level and shear stress of the second sample and samples with the applied lubricant materials or coatings are determined at their stretching out through rigidly fixed rolls, meanwhile the moment of resistance to rotation of rolls at their braking and normal force acting at rolls from the samples at their deforming are determined by force sensors and roll braking device, and using these forces, determined by sensors, a friction force is determined by the formula: T_fr.=P_sens.×L/R, where T_fr. - friction force, R - roll radius, P_sens. - braking force, measured by sensor, L - length of the braking device lever, and friction coefficient by the formula: f=T_fr./2N=P_sens.×L/R×2N, where f - friction coefficient, N - normal load, i.e. force acting at rolls from the side of samples at their deforming, determined by force sensors. The device for the implementation of the above method is described as well.;EFFECT: expansion of functional capabilities and improvement of reliability of assessment.;2 cl, 1 ex, 1 tbl, 5 dwg