Internal cracking of continuous casting billet rectification
In the production of steel ingot, oxidation and decarbonization of steel ingot surface should be prevented. In recent years, due to the development of electric furnace steelmaking and continuous casting, electric furnace steelmaking and continuous casting are increasingly used. The steel ingot produced by this technology is generally required to be rectification, that is, secondary processing of steel ingot to correct defects such as shape and size.
Continuous casting billet straightening is an important process in the whole production of steel ingot. Generally, it is carried out by several sets of straightening machines. During the process of straightening, the inner stress of the steel ingot increases from the surface layer to the interior layer. If the cooling time is not guaranteed, the inner stress can not be released in time, resulting in internal cracks.
Internal cracking of continuous casting billet rectification mainly results from factors such as improper heating temperature and conduction mode, material type and internal stress state of the ingot. Improper heating temperature and conduction mode will lead to excessive generation of internal stress of the ingot, resulting in internal cracking after straightening. In addition, the size of billet and the structure and strength properties of material will also affect the internal stress state of billet in the process of straightening. Poor toughness and strength of material will make the internal stress not easy to release, leading to internal cracking.
To prevent the internal cracking of continuous casting billet rectification, it is necessary to take reasonable measures in the process of steelmaking and straightening. It is necessary to strictly control the heating temperature and conduction mode of steel ingot. For example, the heating temperature should be adjusted according to the size of ingot and its thermal inertia, so as to ensure the reasonable heating effect. At the same time, the temperature should be appropriately reduced to ensure that the ingot surface has sufficient cooling time, so as to avoid the excessive accumulation of internal stress. Moreover, for lighting, ingots with different sizes are suitable for different straightening speeds to ensure quality. In addition, when the ingot material is not good in toughness and strength, appropriate measures should be taken to improve the internal stress state of the material, so as to reduce the occurrence of internal cracks.
In general, in the process of steelmaking and casting continuous casting billet straightening, it is necessary to take professional measures to prevent the occurrence of internal cracking, so as to ensure the quality of steel ingot and meet the production requirements.
