Resumo

RODRIGUES, Alessandro Roger et al. Surface integrity analysis when milling ultrafine-grained steels. Mat. Res. [online]. 2012, vol.15, n.1, pp. 125-130.  Epub 13-Dez-2011. ISSN 1516-1439.  http://dx.doi.org/10.1590/S1516-14392011005000094.

This paper quantifies the effects of milling conditions on surface integrity of ultrafine-grained steels. Cutting speed, feed rate and depth of cut were related to microhardness and microstructure of the workpiece beneath machined surface. Low-carbon alloyed steel with 10.8 µm (as-received) and 1.7 µm (ultrafine) grain sizes were end milled using the down-milling and dry condition in a CNC machining center. The results show ultrafine-grained workpiece preserves its surface integrity against cutting parameters more than the as-received material. Cutting speed increases the microhardness while depth of cut deepens the hardened layer of the as-received material. Also, deformations of microstructure following feed rate direction were observed in workpiece subsurface.

Palavras-chave : milling; surface integrity; microstructure; microhardness; ultrafine-grained steel.