Quality Inspection for Lf Graphite Electrodes With Nipples - UHP 450mm Graphite Electrode – Hexi

Graphite electrodes play an important role in steelmaking industry, they are often used to melt the scrap in electric arc furnaces(abbreviated as EAF) . There are some key properties which determine the quality of electrode, what are they?

The coefficient of thermal expansion

(abbreviated as CTE) refers to a measure of the degree of expansion of a material after being heated, when the temperature increases by 1°C, it causes the expansion degree of solid material sample in a specific direction, which is called the linear expansion coefficient along that direction with unit 1×10-6/℃. Unless otherwise specified, the thermal expansion coefficient refers to the linear expansion coefficient. The CTE of the graphite electrode refers to the axial thermal expansion coefficient.

The bulk density

is the ratio of the mass of the graphite electrode to its volume, the unit is g/cm3. The larger the bulk density, the denser the electrode. Generally speaking, the larger the bulk density of the same type of electrode, the lower the electrical resistivity.

Elastic modulus 

is an important aspect of mechanical properties, and it is an index to measure the elastic deformation ability of a material. Its unit is Gpa. Simply speaking, the greater the elastic modulus, the more brittle the material, and the smaller the elastic modulus, the softer the material.

The level of elastic modulus plays a comprehensive role in the use of electrodes. The higher the volume density of the product, the denser the elastic modulus is, but the poorer the product’s thermal shock resistance is, and the easier it is to generate cracks.

Physical Dimension