What is the effect of the cooling method of alloy structural steel ingots on their performance?
Publish Time: 2025-02-18
As an important material widely used in machinery manufacturing, automobiles, aerospace and other fields, the performance of alloy structural steel is directly related to the quality and service life of the product. In the production process of alloy structural steel, the cooling method of the ingot is a crucial link, which directly affects the microstructure and macroscopic properties of the steel.The cooling methods of alloy structural steel ingots mainly include stack cooling, mold cooling and pit cooling. Different cooling methods will cause different thermal stresses, structural transformations and precipitation behaviors inside the ingot, thus affecting the mechanical properties, physical properties and corrosion resistance of the steel.Stack cooling is to stack the demolded ingots directly in a dry and windproof place and cool them naturally in the air. This method has a faster cooling speed and is suitable for small pearlite steel ingots with low carbon content. However, stack cooling may cause greater thermal stress and structural inhomogeneity inside the ingot, thus affecting the toughness and plasticity of the steel.Mold cooling is to stack the ingot with the mold in a dry and wind-proof place for cooling after the ingot is uncapped, and then demold and air-cool it after the ingot body cools to a certain temperature. Mold cooling can effectively slow down the cooling rate of the ingot, reduce thermal stress, and help obtain a more uniform structure. This method is suitable for larger ingots or pearlite steel with a higher carbon content.Pit cooling is to quickly demold the ingot after solidification, stack it upright in a slow cooling pit, and cover it for slow cooling. Pit cooling has the slowest cooling rate, which can further reduce thermal stress, reduce structural defects, and help obtain good comprehensive performance. Pit cooling is suitable for various steel grades, especially crack-prone, heavy ingot medium-carbon pearlite steel and low-carbon semi-martensitic steel.It is worth noting that the choice of cooling method not only affects the internal structure and performance of the ingot, but also affects the subsequent heat treatment and processing process. Therefore, in actual production, it is necessary to comprehensively consider and select the appropriate cooling method based on factors such as the grade, composition, size and use requirements of alloy structural steel.In summary, the cooling method of alloy structural steel ingot has an important influence on its performance. By rationally selecting the cooling method, the internal structure of the ingot can be optimized, the mechanical properties, physical properties and corrosion resistance of the steel can be improved, and a good foundation can be laid for subsequent processing and use.
