Effect of Nb addition on the machinability of a pearlitic gray cast iron.
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Date
2022
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Abstract
Due to its high thermal conductivity, good damping performance and superior machinability, gray cast iron
(GCI) has found many applications in the automotive industry. However, this material has given way to
other cast irons due to the need for materials with higher mechanical strength and toughness. Actual efforts
have been made to reformulate the GCI chemical composition to obtain different microstructures for
improving its mechanical properties. In this study, the influence of Nb content on the microstructure and
machinability of GCI was investigated when turning under cutting speeds of 240, 360, and 480 m/min, feed
rates of 0.25 and 0.50 mm/rev, and using two different chip breaker geometries (Flat Top and GH). The Nb
addition decreased the graphite size and refined the pearlitic interlamellar spacing. However, it did not
produce significant alteration in the number of eutectic cells and hardness. Regardless of the Nb content,
the presence of chip breaker GH and the lower levels of cutting speed and feed rate were associated with
superior machinability. The increase in the Nb content in the GCI raised all the components of the
machining forces, yet it did not promote significant changes in the chip temperature and decreased the
surface roughness after turning.
Description
Keywords
Cast iron, Characterization, Chip temperature, Cutting forces, Machining
Citation
REIS, B. C. M. et al. Effect of Nb addition on the machinability of a pearlitic gray cast iron. Journal of Materials Engineering and Performance, v. 31, p. 5983-5999, jul. 2022. Disponível em: <https://link.springer.com/article/10.1007/s11665-022-06669-9>. Acesso em: 03 maio 2023.