Značaj istorije deformisanja i tribo-uslova pri određivanju granične deformabilnosti tankih limova

Abstract

Presented in the paper are the influences of the tribo conditions and the strain path on realization of limit relations in typical stress-strain scheme of deep drawing-stretching. Investigation was performed on four materials aimed for deep drawing, out of which the two types of thin sheets have anti-corrosion coating of zinc. Standard stretchings were realized, and as examples of nonproportional forming were realized two phased trajectories with usage of different lubricants. We conclude that realized two different two phased forming - in the first phase uniaxial tension and biaxial tension, in the second phase stretching - enables realization of greater degree of limiting strain, than in conditions of proportional forming process. However, realized values of the greatest depths of drawing, as the key indicators of integral strain analysis, are the significantly lower.