Production methods and technical parameters of German standard rail steel
I. Introduction. German standard rail steel is an excellent steel, which is widely used in rail transit fields such as railways, subways and light rail. Its excellent performance and stability have been widely recognized. This article will introduce the production methods and technical parameters of German standard rail steel in detail to help readers understand the manufacturing process and characteristics of this excellent steel.
Second, the production method.
1.Iron-making process.
The ironmaking process of German standard rail steel adopts the blast furnace method, and the main raw materials are iron ore, coke and limestone. Through blast furnace smelting, the iron ore is reduced to pig iron, and impurities are removed at the same time to obtain pure molten iron.
2.Steelmaking process.
The steelmaking process adopts converter method and electric furnace method, and the chemical composition of the steel is adjusted to meet different performance requirements by adding an appropriate amount of alloying elements, such as silicon, manganese, chromium, nickel, etc. At the same time, the impurities in the steel are removed by blowing oxygen, adding lime, etc., to improve the purity of the steel.
3.Rolling process.
The rolling process is a key part of the production of German standard rail steel, including four stages: initial rolling, soaking heat, middle rolling and finishing rolling. By controlling the rolling temperature, speed and deformation of the pass, the required specifications and properties of the rail steel are obtained. After rolling, cooling, straightening and surface treatment are required to ensure the flatness and surface quality of the steel.
3. Technical parameters.
1.Chemical composition.
The chemical composition of German standard rail steel is strictly in accordance with the German standard DIN 16740, and the main alloying elements are carbon, silicon, manganese, phosphorus, sulfur, etc. The carbon content is higher to ensure the strength and hardness of the steel; moderate silicon content to improve the elasticity and corrosion resistance of the steel; The manganese content is lower to reduce the cold brittleness of the steel. At the same time, the content of harmful elements such as phosphorus and sulfur is strictly controlled to improve the toughness and durability of steel.
2.Mechanical properties.
German standard rail steel has excellent mechanical properties, including tensile strength, yield strength, elongation and impact toughness. Its tensile strength is generally above 600MPa, yield strength is about 350MPa, elongation is above 20%, and it has good plasticity and toughness. In addition, German standard rail steel also has good wear resistance and fatigue resistance, and can withstand long-term high-intensity operation.
3.Dimensional accuracy and appearance quality.
The dimensional accuracy of German standard rail steel is high and the tolerance range is small. Depending on the application, there are strict standards for length, width, and thickness. The appearance quality is excellent, the steel surface is smooth and flat, and there are no obvious cracks, bubbles and inclusions. In addition, German standard rail steel also has good corrosion resistance and welding performance, which can meet the requirements of use in various complex environments.