Continuous Casting Blooms Defects
Steel blooms are the source material used for many modern manufactured products. Bloom shapes come in various sizes and shapes and are used to manufacture products of differing specifications. In the production process, one of the most common methods of producing blooms is continuous casting. With this process a molten steel bloom is formed and refined as it emerges from a tundish onto a moving caster surface. The steel is continuously solidified and supplied to a rolling mill where it is re-heated and processed. However, due to a range of variables in the production process, blooms can often be imperfect, containing different defects which can affect the steel’s integrity and quality.
Continuous casting blooms are usually subject to a range of surface defects caused by flaws in the production process. These can often appear as folds, cracks, pits, or a combination of different deformities. Pinhole activities, as well as macrostructure irregularity, are also common. Generally, these defects are the result of a number of environmental and manufacturing variables, such as variations in tundish inventory, casting speed, levels of nitrogen in the steel, pull angles, and cooling strategies.
An effective defect analysis is essential to help control defects in bloom production. Bloom samples should be inspected and analyzed before being sent to the rolling mill in order to identify potential defects. Visual analysis should be performed with a magnifying lens or microscope, as well as macro properties or/and mm microstructural analysis, particularly on surface defects.
The most common technique used to analyse surface defects is known as the “Short Bent Check System”. In this system, a specially designed tool is used to detect surface defects. The tool is designed with a bulb tip on one end and its blades are bent in such a way that when the tool is passed over a bloom, it can feel the surface bumps or irregularities. The tool is equipped with a profilometer that provides data to detect irregularities in a sample’s surface profile. This system can be used for detection and analysis of cracks, folds, pits, and other surface deformities.
In order to prevent bloom defects, it is important to maintain a high level of quality control. Factors that may cause defects should be carefully monitored and controlled during the production process. Casting parameters, such as tundish inventory, cooling strategies, and casting speeds, should be regularly checked and monitored. The quality of the steel in the tundish should also be monitored and maintained to ensure that it is of good quality and consistency. Additionally, visual quality control checks of blooms should be performed regularly in order to detect defects which can then be addressed.
Continuous casting blooms are the source material used for many modern manufactured products. Steel blooms are often subject to defects caused by flaws in the production process. To ensure the integrity and quality of blooms, it is important to maintain a high level of quality control during the production process, such as monitoring tundish inventory, cooling strategies, and casting speeds. Additionally, inspections and tests should be regularly performed in order to detect and address surface defects.
