Lamel Grafitli Dökme Demir Motor Bloklarında Gerilim Giderme Tavlama Süresinin Mekanik Özellikler ve İşletme Maliyeti Üzerinde Etkileri
Abstract
Çalışmada, EN GJL-250 lameller grafit gri dökme demirden yapılmış motor bloklarının mekanik özellikleri ve kalıntı gerilim seviyeleri üzerinde genişletilmiş gerilim giderme ısıl işlem sürelerinin etkisi araştırılmıştır. Yüksek mekanik mukavemet, ısıl iletkenlik ve yorulma direnci standartları için hayati önem taşıyan motor blokları, seri üretim sırasında homojen olmayan soğutma nedeniyle iç gerilimler geliştirir. Tam ölçekli motor bloklarına iki farklı gerilim giderme ısıl işlem döngüsü uygulanarak kalıntı gerilimler, sertlik, çekme dayanımı, boyutsal kararlılık, mikro yapı ve işletme maliyetleri üzerindeki etkileri değerlendirilmiştir. Sonuçlar, tavlama süresinin artırılmasının, sertlik, çekme dayanımı veya mikro yapıda önemli bir değişiklik olmaksızın kalıntı gerilimleri %50-%80 oranında azalttığını göstermiştir. Genişletilmiş döngüyle ilişkili maliyet artışı marjinal olmuştur (%0,4 birim başına).
Keywords
Lamel grafitli dökme demir – Gerilim-Giderme ısıl işlemi mekanik özellikler Kalıntı gerilmesi Motor Blok
References
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- Alagar, A. et al. (2020). Investigation on thermal fatigue and stress evolution in engine components. Materials Today: Proceedings.
- Baş, B., & Şen, N. B. (2007). Effects of cooling rates on residual stress formation in cast components. Journal of Materials Processing Technology, 187–188, 375–381. https://doi.org/10.1016/j.jmatprotec.2006.11.077 Chen, R. et al. (2023). Energy-efficiency analysis of annealing treatments for ferrous alloys. Journal of Manufacturing Processes.
- Çoşar, B., & Yenici, B. S. (2020). Optimization of heat treatment parameters in engine block manufacturing. International Journal of Cast Metals Research, 25(2), 115–123. https://doi.org/10.1080/13640461.2019.1709480
- Deng, L. et al. (2022). Stress-relief annealing for improving fatigue life in large gray iron castings. Metallurgical and Materials Transactions A.
- Li, W., Zhang, H., & Wang, Y. (2021). Analysis of graphite morphology and thermal properties in gray cast iron. Journal of Materials Engineering and Performance.
- Mishra, S. & Shukla, M. (2019). Optimization of heat treatment cycle in cast irons using FEM. Materials Science Forum.
- Rao, P. N. (2013). Manufacturing technology: Foundry, forming and welding (Vol. 1). McGraw-Hill Education. Stefanescu, D. M. (2009). Science and engineering of casting solidification. Springer. https://doi.org/10.1007/978-0-387-30702-0
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Effects of Stress Relief Annealing Time on Mechanical Properties and Operating Costs in Lamellar Graphite Cast Iron Engine Blocks
Abstract
The study explores the impact of extended stress-relief heat treatment durations on the mechanical properties and residual stress levels of motor blocks made from EN GJL-250 lamellar graphite gray cast iron. Motor blocks, which are crucial for high standards of mechanical strength, thermal conductivity, and fatigue resistance, develop internal stresses during mass production due to non-uniform cooling. Two different stress-relief heat treatment cycles were applied to full-scale motor blocks, evaluating their effects on residual stresses, hardness, tensile strength, dimensional stability, microstructure, and operational costs. The results showed that increasing the annealing time reduced residual stresses by 50%-80% without significant changes in hardness, tensile strength, or microstructure. The cost increase associated with the extended cycle was marginal (0.4% per unit).
Keywords
Lamellar graphite cast iron stress relief annealing mechanical properties residual stress engine block
References
- Arran, A., & Elliott, R. (2009). Cost analysis of heat treatment in high volume foundry production. Foundry Trade Journal, 183(3673), 24–30.
- Alagar, A. et al. (2020). Investigation on thermal fatigue and stress evolution in engine components. Materials Today: Proceedings.
- Baş, B., & Şen, N. B. (2007). Effects of cooling rates on residual stress formation in cast components. Journal of Materials Processing Technology, 187–188, 375–381. https://doi.org/10.1016/j.jmatprotec.2006.11.077 Chen, R. et al. (2023). Energy-efficiency analysis of annealing treatments for ferrous alloys. Journal of Manufacturing Processes.
- Çoşar, B., & Yenici, B. S. (2020). Optimization of heat treatment parameters in engine block manufacturing. International Journal of Cast Metals Research, 25(2), 115–123. https://doi.org/10.1080/13640461.2019.1709480
- Deng, L. et al. (2022). Stress-relief annealing for improving fatigue life in large gray iron castings. Metallurgical and Materials Transactions A.
- Li, W., Zhang, H., & Wang, Y. (2021). Analysis of graphite morphology and thermal properties in gray cast iron. Journal of Materials Engineering and Performance.
- Mishra, S. & Shukla, M. (2019). Optimization of heat treatment cycle in cast irons using FEM. Materials Science Forum.
- Rao, P. N. (2013). Manufacturing technology: Foundry, forming and welding (Vol. 1). McGraw-Hill Education. Stefanescu, D. M. (2009). Science and engineering of casting solidification. Springer. https://doi.org/10.1007/978-0-387-30702-0
- Yang, J. et al. (2021). Residual stress characterization in cast iron blocks using neutron diffraction. International Journal of Cast Metals Research.
Details
| Primary Language | English |
|---|---|
| Subjects | Material Production Technologies, Materials Engineering (Other) |
| Journal Section | Research Articles |
| Authors | |
| Publication Date | July 30, 2025 |
| Submission Date | May 22, 2025 |
| Acceptance Date | July 4, 2025 |
| Published in Issue | Year 2025 Volume: 2 Issue: 2 |