A superior strength and sliding-wear resistance combination of ductile iron with nanobainitic matrix

A nanobainitic matrix composing of nanoscale a phase and carbon-riched g phase was obtained for the ductile iron by austempering treatment. The microstructure and proper-ties of ductile iron were compared with GCr15. The microstructural characteristic gave rise to a good strength with an ultimate tensile strength higher than 1200 MPa, which was comparable and even superior to conventionally forged steels. The friction coefficient of the ductile iron was approximate 1/3 compared with that of commercial GCr15 under dry sliding wear condition, which was related to the existence of homogeneously distributed spheroidal graphite in ductile iron. The low friction coefficient and moderate strength resulted in a superior wear resistance of ductile iron with nanobainitic matrix by contrast to GCr15. (C)2021 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

The nanobainitic matrix in ductile iron, composed of nanoscale a phase and carbon-riched g phase, exhibits superior strength and wear resistance compared to conventionally forged steel GCr15. This is attributed to the homogeneous distribution of spheroidal graphite, resulting in a low friction coefficient and moderate strength in ductile iron.