High-speed steel can be divided into four categories: Traditional Casting Technology, Electroslag Remelting Technology, Powder Metallurgy Technology, and Injection Molding Technology according to its preparation process. Among them, traditional high-speed steel can be divided into ordinary high-speed steel, high-performance high-speed steel, and low-alloy. High-speed steel, etc. As a kind of high-alloy ledeburite steel, the carbon content in high-speed steel can exceed 1%, and the type, quantity, size and distribution of carbides are the key factors that determine its performance. Therefore, different preparation processes have an important impact on the properties of high-speed steel.
Traditional Casting Technology
Overview: Traditional casting high-speed steel has simple process and low cost. However, due to its slow solidification rate, a large amount of segregation of carbon and alloying elements is formed before crystallization, thereby forming an intergranular carbide network. In order to eliminate the uneven distribution of carbides, repeated forging or rolling at high temperature is used to make them broken and evenly distributed. This forging process is prone to cracking, and is limited by processing equipment and forging ratios, resulting in high-speed steel from ingots. To the final product, the utilization rate of the material in the whole process is only between 24%-36%.
Disadvantages: The high-speed steel using traditional casting preparation process is prone to stress concentration, high brittleness, poor toughness, and low yield rate during use.
Electroslag Remelting Technology
Overview: Electroslag remelting technology is a kind of refined metallurgical technology. It is a major metallurgical technology advancement, especially in improving the macrostructure of high-speed steel and improving the quality of steel. It is a comprehensive metallurgical casting process that combines secondary refining and directional solidification of molten steel. This method can reduce the sulfur and phosphorus content of molten steel, increase the purity of molten steel, and improve the macrostructure of steel. Due to the faster cooling rate of the electroslag ingot, the carbide distribution in the steel is more uniform, and the improvement of the structure also improves the thermoplasticity of the high-speed steel.
Disadvantages: Despite various advances and advantages, the electroslag remelting and solidification rate is still low, the crystal grains are still relatively large, the carbide size distribution is still uneven, and its energy consumption is high, the production efficiency is low, and fluoride is generated during the production process. Great harm to the environment and human body.
Post time: Sep-02-2021