LITERATURE REVIEW ON THE OPTIMAL COMPOSITION OF SECONDARY-METAL-BASED GGG-45 (EN-GJS-450-10) SPHEROIDAL GRAPHITE CAST IRON AND TECHNOLOGY FOR MANUFACTURING AUTOMOTIVE COMPONENTS

The increasing demand for sustainable engineering materials has encouraged the extensive utilization of secondary metallic raw materials in cast iron production. Among various grades of ductile iron, GGG-45 (EN-GJS-450-10 according to European standards) has gained significant attention due to its balanced combination of strength, ductility, wear resistance, machinability, and economic efficiency. The application of recycled ferrous scrap in the production of GGG-45 ductile iron presents both opportunities and challenges. Secondary metal resources reduce production costs, conserve natural resources, and minimize environmental impacts associated with mining and primary metal extraction. However, the variability in chemical composition, contamination by residual elements, and process instability may negatively affect the microstructure and mechanical properties of the final cast product. Therefore, determining the optimal chemical composition and technological parameters for producing high-quality spheroidal graphite cast iron from recycled materials remains a critical research area. Numerous studies conducted in Europe, Asia, North America, and other industrial regions have investigated the influence of carbon, silicon, manganese, sulfur, phosphorus, magnesium, and rare earth elements on the formation of spheroidal graphite structures. Researchers have reported that maintaining carbon equivalent values between 4.2 and 4.5% promotes excellent castability while preventing excessive carbide formation. Silicon contents ranging from 2.2 to 2.8% enhance graphitization and ferrite formation, whereas manganese should generally remain below 0.4% to avoid pearlite stabilization and carbide precipitation. Sulfur and phosphorus are particularly detrimental to nodularity and mechanical performance and should be carefully controlled below 0.02% and 0.05%, respectively. The successful production of GGG-45 from secondary metals depends heavily on melt treatment techniques, especially magnesium treatment and inoculation practices. Modern foundries increasingly employ sandwich, tundish-cover, and wire-feeding methods to ensure consistent graphite nodularization. Furthermore, advanced inoculants containing ferrosilicon, calcium, barium, and rare earth elements significantly improve graphite nucleation and reduce shrinkage defects. Process optimization using computer simulation tools has also contributed to improved casting quality and reduced rejection rates. Automotive industries worldwide utilize GGG-45 ductile iron for manufacturing crankshafts, steering knuckles, differential housings, suspension brackets, wheel hubs, brake components, and gearbox casings. These components require reliable mechanical properties, including tensile strengths above 450 MPa, yield strengths exceeding 300 MPa, and elongation values greater than 10%. The literature demonstrates that properly controlled secondary-metal-based ductile iron can achieve these requirements while maintaining economic competitiveness and environmental sustainability. Recent developments focus on integrating Industry 4.0 technologies, artificial intelligence, machine learning algorithms, and real-time process monitoring systems into foundry operations. These innovations enable predictive control of chemical composition, melt quality, and solidification behavior. Additionally, life-cycle assessment studies have shown that recycled-metal-based ductile iron production significantly reduces greenhouse gas emissions and energy consumption compared with primary-metal routes. This literature review synthesizes contemporary findings regarding the optimal composition, microstructural development, processing technologies, mechanical performance, and industrial applications of GGG-45 spheroidal graphite cast iron produced from secondary metallic resources. The review highlights key factors influencing material quality and provides recommendations for future research aimed at improving sustainability, process reliability, and component performance in automotive manufacturing.

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