Abstract
In the production process of continuous casting slab, the unreasonable secondary cooling system can lead to serious crack defects. This study focuses on the problem of cracks in nuclear power stainless steel produced by vertical continuous casting under soft reduction conditions. Based on the actual production process parameters, the thermomechanical finite element model was established to investigate the effects of water distribution in the secondary cooling zones on cracks by using ProCAST. The results show that the stress concentration is obvious under the original process, especially the positions of 4 mm below the wide surface and 6 mm below the narrow surface. It is easy to generate cracks, and the area with the highest hot‐tearing index is approximately 26 cm2. In addition, the secondary cooling system is adjusted based on the existing problems of the original process. The temperature of the casting slab rises by about 15°C at the solidification end point, and the length of the liquid core increases by about 0.5 m when the quantity of the water flow decreases in zone 2 and zone 3. The stress concentration is alleviated, and the possibility of cracking is reduced. Especially, it is evident that the proportion of water on the loose side margin increases from 40% to 45%, while the proportion of water on the fixed side margin of zone 3 is adjusted from 56% to 60%.
Highlights
E nuclear power stainless steel is the most conspicuous in the production of many steel grades because it has good comprehensive mechanical properties, excellent strength at high temperatures, and stress corrosion resistance and is widely used in the industry [14,15,16]
Based on the high-temperature mechanical properties of the slab and the soft reduction process parameters and the solidification characteristics of the slab, the mathematical model was established to simulate the influence of water distribution on cracks by ProCAST. e possibility of crack occurrence is reduced by optimizing water distribution in the secondary cooling section, and the simulation results would be helpful in further improving the quality of the steel
In the process of continuous casting, the cooling intensity in the secondary cooling zone plays an important role, which determines the quality of the casting slab to a large extent [38]. erefore, the reasonable secondary cooling water distribution can effectively reduce the possibility of casting defects and ensure the efficient production of continuous casting process
Summary
Due to the heat transfer along the casting direction in the continuous casting process, which can be neglected for it takes up about 3%∼6% of the total heat [25]. Erefore, the thermomechanical behavior of continuous casting process is simulated by using the thinslicing method in this paper. In order to save the calculation time, the model takes half of the casting slab section for calculation; the size of the slice is 650 mm × 200 mm × 3 mm. The width, casting direction, and thickness along the slab are, respectively, the coordinates X, Y, and Z directions, and the grid element is a hexahedral grid with a size of 6.5 mm × 6.5 mm.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
