Investigation of Plastic Properties of Ø8 Rod Made of Fire-Refined Copper of Kmor Grade

Abstract

Results of the comparative ductility evaluation of Ø8 rods made of copper of the KM and KMor grades are discussed. It has been found out that plastic properties of KM and KMor grade rods at room temperature practically do not differ in their specific elongation and after-fracture contraction indices. At the same time, the ductility indices of KMor rod at temperature +850 °С became, practically, half-values. Increased spread of physical property values particularly the specific ohmic resistance of the rod KMor can be explained by the cumulative effect of variations of the chemical metal composition, and changes in process variables of the process (for example, unstable density of a cast bar), that initiate an occurrence of tension stresses during rolling. Calculation data of the limiting drawing ratio μr demonstrated that its value must not exceed 1.475.