rp graphite electrode factory
rp graphite electrode factory quality index
The quality index of rp graphite electrode factory reflects the quality and performance of rp graphite electrode factory. The main indexes are bulk density dB, electrical resistivity ρ, bending strength σ, elastic modulus e, thermal expansion coefficient α and ash content a%. According to the difference of these indicators and the difference of raw materials and manufacturing processes, according to the national standard (Yb/T 4088/89/) the rp graphite electrode factory is divided into three categories: ordinary power rp graphite electrode factory (RP), high power rp graphite electrode factory (HP), ultra-high power rp graphite electrode factory (UHP).
According to user needs, the rear rp graphite electrode factory has added two kinds of high bulk density rp graphite electrode factory (hd) and quasi-super high rp graphite electrode factory (SHP). On the basis of national standards, each company has its own corporate standards, and customers will put forward their own quality standards when placing orders.
1. The bulk density is the ratio of the mass of the rp graphite electrode factory sample to its volume, and the unit is g/cm3. The higher the volume density, the greater the density of the rp graphite electrode factory. It is positively correlated with strength and oxidation resistance. Generally speaking, the higher the volume density, the lower the resistivity. The methods to increase the bulk density are: adjust the formula, increase the amount of small particles and powder, use high-density coke, use high-coking pitch, and increase the number of impregnations.
2. Resistivity is a parameter to measure the conductivity of rp graphite electrode factory. Refers to the resistance characteristics of the conductor to the current when the current passes through the conductor. It is equal to the resistance of a conductor with a length of 1m and a cross-sectional area of 1m2 at a certain temperature. The unit is μΩ·m. The lower the resistivity, the better the conductivity and the lower the consumption. Methods to reduce resistivity include: using high-quality raw materials, increasing the volume density of the product, and increasing the graphitization temperature.
3. Bending strength is a parameter that characterizes the mechanical properties of graphite materials, also known as bending strength. Refers to the ultimate resistance of an object under the action of an external force, when the external force is perpendicular to the axis of the object, and the object is first bent to the breaking moment under the action of the external force, in megapascals. The strength of graphite material is different from other metal and non-metal materials. The strength of graphite materials increases with the increase of temperature, reaching the maximum value at ℃, which is 1.8-2 times the strength of normal temperature, and then decreases. The high-strength rp graphite electrode factory and joint are more difficult to break during use. The way to improve the flexural strength is to reduce the particle size of the coke in the formula, increase the strength of the carbon raw material, increase the bulk density of the product, and reduce the internal defects of the product.
4. The modulus of elasticity is an important aspect of mechanical properties, and it is an index to measure the elastic deformation ability of materials. Refers to the stress-strain ratio within the elastic deformation range of the material, and the unit is GPA. The greater the modulus of elasticity, the greater the stress required to produce a certain amount of elastic deformation. In short, the greater the modulus of elasticity, the more brittle the material, and the smaller the modulus of elasticity, the more flexible the material. Elastic modulus plays a comprehensive role in the use of rp graphite electrode factory. The higher the volume density of the product, the greater the density and the greater the modulus of elasticity. However, the poorer the thermal shock resistance of the product, the easier it is to crack and fall off. In production, it is often through adjusting the particle size in the formula and the bulk density of the product to grasp a relatively suitable elastic modulus value to meet the requirements of use.
5. The coefficient of thermal expansion is a measurement of the degree of expansion of a material after being heated, that is, when the temperature rises by 1℃, it causes the expansion ratio constant of a unit solid material sample in a specific direction, which is called the linear expansion coefficient along the direction, unit: 1×10 -6/℃. Unless otherwise specified, the coefficient of thermal expansion refers to the coefficient of linear expansion. The axial and radial linear expansion coefficients of rp graphite electrode factory are quite different, which is 0.8-1 times the axial expansion coefficient. The thermal expansion coefficient in the quality index of rp graphite electrode factory refers to the axial thermal expansion coefficient. The thermal expansion coefficient of rp graphite electrode factory is a very important thermal parameter. The lower the value, the stronger the thermal stability of the product, the higher the oxidation resistance, the less breakage, and the lower the consumption. Ways to reduce the coefficient of thermal expansion: mainly determined by the inherent characteristics of raw materials, select high-quality raw materials. The formula uses a larger particle size formula or increases the number of larger particles (but it will reduce the density and strength of the product).
6. Ash content refers to the content of other solid elements in the product except carbon graphite. The ash content of the rp graphite electrode factory is mainly affected by the ash content of the raw material. The ash content of petroleum coke needle coke is low, and the ash content of rp graphite electrode factory is generally less than 0.5%. Ash content within 1% has no obvious effect on steelmaking, but impurity elements in ash content will reduce the oxidation resistance of rp graphite electrode factory. 7. The coefficient of thermal vibration resistance is a parameter that characterizes the performance of thermal vibration resistance. Thermal vibration resistance is a characteristic of the material itself. It describes a resistance to sudden cold and heat. In other words, resistance to material fragmentation under a certain temperature gradient is a performance and a very important comprehensive factor that affects the use of rp graphite electrode factory. K—thermal shock resistance coefficient, w/M; σ—tensile strength, MPa; e—modulus of elasticity, MPa; λ—thermal conductivity, w/M·K; α—coefficient of thermal expansion, 1/KK is a relative value, The larger the value, the stronger the thermal shock resistance.
The K value of the rp graphite electrode factory has a high correlation with the performance of the electric arc furnace, that is, the higher the K value, the smaller the rupture and fracture of the rp graphite electrode factory.