An analysis of the machinability of ASTM grades 2 and 3 austempered ductile iron

作者：de Carvalho Marcelo Vasconcelos^*; Montenegro Davi Melo; Gomes Jefferson de Oliveira

来源：Journal of Materials Processing Technology, 2013, 213(4): 560-573.

DOI：10.1016/j.jmatprotec.2012.11.004

• ADI
• Machinability
• Cutting forces
• Tool life
• Chip characteristics
• Quick-stop

The main goal of this work is to perform an analysis of the machinability of two ASTM grades of ADI, namely 2 and 3. The samples used in this work were cast and austempered according to ASTM standards for the production of grade 2 (G2) and grade 3 (G3) ADI. Characterization was accomplished through tensile and hardness tests, metallography and X-ray diffraction. Machinability was evaluated by analyzing tool life, cutting forces, surface finish and chip characteristics in turning operations. A quick-stop test was also performed in order to verify some mechanical processes during the chip formation and to analyze the shear plane angle. Tool life when machining G2 was 33% lower than G3 (18 min against 26 min), although the latter is a harder material. Abrasion and adhesion were the wear mechanisms observed through SEM images, whereas in other cast irons mainly abrasion is observed. Cutting forces measurements showed that the value of K-c1.1 decreased 19%, from 1448 to 1175 N/mm(2), for G2 as the depth of cut increased from 2 to 5 mm at a cutting speed of 80 m/min and 18%, from 1501 to 1236 N/mm(2), for G3. Surface roughness measurements proved that a smoother surface is obtained for both alloys at f=0.10 mm/rev when using an insert with nose radius 1.6 mm instead of smaller radii. Both alloys presented similar surface quality. All chips observed were segmented.

• 出版日期2013-4