This study explores the effect of low-temperature treatment (LTT) on the graphitization behavior of malleable cast iron during annealing. The results show that a properly selected LTT regime significantly promotes the formation of graphite inclusions, thereby accelerating cementite decomposition. The efficiency of LTT is determined by several key factors, including treatment temperature, duration, number of cycles, and the pre-treatment cooling conditions. Single-stage LTT is most effective at 300–400°C, while double and multi-stage treatments demonstrate enhanced performance, especially when the first cycle is conducted within 100–400°C. Longer exposure times further improve graphite inclusion formation, and the resulting structural changes remain stable even after prolonged storage at room temperature. Additionally, slow heating from 20°C to 700°C is identified as a viable alternative to traditional LTT, offering similar structural benefits. The most effective annealing approach involves holding the material at 300–400°C followed by a gradual rise to the pearlite transformation range, a method well-suited to the capabilities of standard industrial equipment. These findings provide valuable guidance for optimizing heat treatment practices in malleable cast iron manufacturing.

Pearlite, malleable cast iron, annealing

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