The electrodes quality and use is determined by the following physical and mechanical properties:
a) Electrical Resistivity: The resistance to the flow of electric current. The lower the value the higher the current flow.
b) Bending Strength: The resistance to bending stresses generated by the charge during melting operations.
c) Tensile Strength: The resistance to axial stresses due to electrodes weight and forces acting during the melting operations.
d) Young's Modulus: The elastic resistance of the electrode’s longitudinal deformation as a function of a tensile or compression load per area of application. A low value is recommended.
e) Volumetric Density: The weight per unit of volume. The higher the density, the better the mechanical and electrical properties.
f) Coefficient of Thermal Expansion: The process requires the electrode’s minimum linear expansion as a function of temperature and must be consistent with the expansion of the nipple; the lower the coefficient the less linear expansion.
g) Ash: Refers to the possibility of loose particles inside the electrode in the form of ashes.
