Abstract:The development of effective methods for di rectly measuring liquid metal quality, prior to casting and final solidification, has long been a goal for Process Metal lurgists. For aluminum, which is generally much cleaner than steel, it is first necessary to concentrate the inclu sions by filtering the metal through a porous frit, before then freezing the remaining metal, and subjecting it to microscopic examination (e.g. PoDFA). An alternative method is to take a sample of metal, freeze it, and then dissolve t… Show more
“…14. 13 So, we still remain `in the dark`regarding actual macro-inclusion sizes, or rather inclusion agglomerates, in liquid steels. While all major steel companies are currently using automated scanning electron microscope energy-dispersive X-ray analysis (EDX) and microanalyses (ASCAT) 14 to analyse individual inclusion particles in the 1-10 µm size range, in solidified samples, this method can say nothing about the size distributions and frequency of all inclusion sizes and inclusion agglomerates, within a liquid steel bath, about to be frozen.…”
Section: The Case Against Nnsc Machinesmentioning
confidence: 99%
“…14. 13 So, we still remain `in the dark` regarding actual macro-inclusion sizes, or rather inclusion agglomerates, in liquid steels. 13A continuous LiMCA II machine (left), and the LiMCA operating principle (right)14ESZ-PAS (easy pass) real time instrument (left), and taking probe measurements at Sorel Forge, Quebec (right)…”
The conventional continuous casting (CCC) of steel, starting in the 1950s, has now become the dominant casting process, worldwide. It presently accounts for about 1.5 billion tonnes of steel cast per year. Nonetheless, given the inexorable forces favouring near net shape casting (NNSC) of semi-finished products, for reasons of economy of scale, process rationalisation and the protection of the environment, the question of how long CCC can continue to dominate in the casting of steel, must remain a question. Two NNSC candidates for steel are the twin roll casting (TRC) and horizontal single belt casting (HSBC) processes. While the TRC of steel sheet by 'CASTRIP' has now been operating commercially for some 12 years within NUCOR, producing low carbon steel sheets, HSBC has only just been commercialised, at Salzgitter's Peine Plant, in Germany, under the name 'Belt Cast Technology'. It had to await the strong demand for high strength high ductility steels for the auto industry. The McGill Metals Processing Centre has been involved in both casting processes since 1987, its research being aimed at addressing the various technical aspects and fundamental problems associated with these two NNSC processes for forming steel sheet material. This paper addresses the pros and cons of NNSC processes versus CCC, and the differences between TRC and HSBC, for future steel sheet production.
“…14. 13 So, we still remain `in the dark`regarding actual macro-inclusion sizes, or rather inclusion agglomerates, in liquid steels. While all major steel companies are currently using automated scanning electron microscope energy-dispersive X-ray analysis (EDX) and microanalyses (ASCAT) 14 to analyse individual inclusion particles in the 1-10 µm size range, in solidified samples, this method can say nothing about the size distributions and frequency of all inclusion sizes and inclusion agglomerates, within a liquid steel bath, about to be frozen.…”
Section: The Case Against Nnsc Machinesmentioning
confidence: 99%
“…14. 13 So, we still remain `in the dark` regarding actual macro-inclusion sizes, or rather inclusion agglomerates, in liquid steels. 13A continuous LiMCA II machine (left), and the LiMCA operating principle (right)14ESZ-PAS (easy pass) real time instrument (left), and taking probe measurements at Sorel Forge, Quebec (right)…”
The conventional continuous casting (CCC) of steel, starting in the 1950s, has now become the dominant casting process, worldwide. It presently accounts for about 1.5 billion tonnes of steel cast per year. Nonetheless, given the inexorable forces favouring near net shape casting (NNSC) of semi-finished products, for reasons of economy of scale, process rationalisation and the protection of the environment, the question of how long CCC can continue to dominate in the casting of steel, must remain a question. Two NNSC candidates for steel are the twin roll casting (TRC) and horizontal single belt casting (HSBC) processes. While the TRC of steel sheet by 'CASTRIP' has now been operating commercially for some 12 years within NUCOR, producing low carbon steel sheets, HSBC has only just been commercialised, at Salzgitter's Peine Plant, in Germany, under the name 'Belt Cast Technology'. It had to await the strong demand for high strength high ductility steels for the auto industry. The McGill Metals Processing Centre has been involved in both casting processes since 1987, its research being aimed at addressing the various technical aspects and fundamental problems associated with these two NNSC processes for forming steel sheet material. This paper addresses the pros and cons of NNSC processes versus CCC, and the differences between TRC and HSBC, for future steel sheet production.
“…Current inclusion detection methods encompass the metallographic method, PoDFA (Porous Disc Filtration Analyzer), K-mold, electrical sensing zone method, and ultrasonic method [9]. The metallographic method, while simple, requires lengthy sampling, making it suitable for small-scale detection.…”
Section: Introductionmentioning
confidence: 99%
“…PoDFA offers both qualitative and quantitative detection but suffers from low efficiency and high costs [10][11][12]. The K-mold method detects 60-80 µm inclusions but yields biased results for cleaner molten metals [9]. Moreover, these methods are offline and cannot provide real-time data on inclusion size distribution in metal melts.…”
Traditional methods for assessing the cleanliness of liquid metal are characterized by prolonged detection times, delays, and susceptibility to variations in sampling conditions. To address these limitations, an online cleanliness-analyzing system grounded in the method of the electrical sensing zone has been developed. This system facilitates real-time, in situ, and quantitative analysis of inclusion size and amount in liquid metal. Comprising pneumatic, embedded, and host computer modules, the system supports the continuous, online evaluation of metal cleanliness across various metallurgical processes in high-temperature environments. Tests conducted with gallium liquid at 90 °C and aluminum melt at 800 °C have validated the system’s ability to precisely and quantitatively detect inclusions in molten metal in real time. The detection procedure is stable and reliable, offering immediate data feedback that effectively captures fluctuations in inclusion amount, thereby meeting the metallurgical industry’s demand for real-time analyzing and control of inclusion cleanliness in liquid metal. Additionally, the system was used to analyze inclusion size distribution during the hot-dip galvanizing process. At a zinc melt temperature of 500 °C, it achieved a detection limit of 21 μm, simultaneously providing real-time data on the size and amount distribution of inclusions. This represents a novel strategy for the online monitoring and quality control of zinc slag throughout the hot-dip galvanizing process.
“…At present, the in situ and online inspecting technique for liquid metal cleanliness mainly is liquid metal cleanliness analyzer (LiMCA) [8][9][10][11], which developed from the Coulter * Authors to whom any correspondence should be addressed.…”
Lorentz force particle analyzer (LFPA) is a non-contact electromagnetic measurement technique for the cleanliness inspection of liquid metal. Based on its principle, an optimized prototype of micro-particle measurement device is designed and built. Inclusion particles of different sizes in millimeter and submillimeter in liquid metal are inspected by this device at room temperature. The characteristics and formation mechanisms of typical inclusion particles pulse signal and laser path signal are compared and discussed. The wavelet decomposition method is used to denoise the original signal, and the desired signal is extracted and sorted out. Results show that LFPA is suitable for the measurement of inclusion particles in liquid metal.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
