The electrode paste is used as a conductive electrode under high and ultra-high temperature conditions. The operating temperature of the electrode extending out of the copper tile of the submerged arc furnace is often about 2000 degrees, and some temperatures are even higher [for example, the carbide smelting temperature is 2000 degrees]. All materials have different thermal shock resistance. Therefore, Chenguang carbon believes that it is very necessary to explore the thermal shock resistance of electrode paste and improve the understanding of the use of electrode paste to ensure normal production and * production.
1、 What is thermal shock resistance. That is, when the material is used at high temperature, it can withstand the drastic change of temperature without being damaged, which is called thermal shock resistance. [or thermal stability]. Thermal expansion and cold contraction is a general principle of physics, that is, when the temperature changes sharply, if the material cannot transfer the heat energy in time, the surface and interior of the material will produce a temperature gradient, and their expansion and contraction are different, resulting in internal stress. When the stress reaches a very limited strength, the material will be destroyed. Therefore, it is necessary to discuss the thermal shock resistance of electrode paste.
2、 Factors affecting thermal shock resistance. According to the research results of carbon experts at home and abroad, the main factors affecting the thermal shock resistance are tensile strength, coefficient of linear thermal expansion, Young’s modulus, bulk density, thermal shock resistance parameters, thermal conductivity, etc.
According to the production and use characteristics of electrode paste, under certain production equipment and process conditions, the tensile strength and bulk density of electrode paste in the sintering process are almost fixed values. For example, the bulk density of electrode paste after sintering is 1.4g per cubic centimeter, and the tensile strength is 6 MPa per square centimeter. Therefore, we can only investigate it from the perspective of production equipment and process.
Young’s modulus and thermal shock resistance parameters that affect thermal shock resistance are constants. The discussion of linear thermal expansion coefficient is complex, and Chenguang metallurgy will make a special discussion. This paper mainly discusses the influence of thermal conductivity on thermal shock resistance.
3、 The role of thermal conductivity in thermal shock resistance index. In solid materials, there are also two ways of heat conduction, one is free electron flow conduction, and the other is heat vibration conduction by lattice atoms. Carbon materials belong to lattice heat conductors. Due to the structure and characteristics of carbon atoms, carbon materials have very good lattice atomic thermal vibration conductivity, and this conductivity also increases with the increase of temperature. The higher the temperature, the higher the thermal conductivity.
4、 Due to its high thermal conductivity, low Young’s modulus and small linear thermal expansion coefficient, carbon material can relieve thermal stress under certain bulk density, so it has strong thermal shock resistance.
The thermal shock resistance of electrode paste is a very complex parameter. There are always things we cannot recognize when discussing under high temperature. Colleagues and colleagues are welcome to correct and discuss.