Nanotribological behavior of cryogenically treated martensitic stainless steel

G. PRIETO; K. BAKOGLIDIS; W. TUCKART; E. BROITMAN

Lewiston, Maine

Encuentro; Gordon Research Conferences; 2016

Gordon Research Conferences

Cryogenic treatments have been employed over the last three decades in both tool and high-alloy steels to improve wear resistance, through the transformation of retained austenite and the precipitation of finer carbides. In this work the nanotribological behavior and mechanical properties at the nano-scale of both deep cryogenically and conventionally treated low-carbon AISI 420 martensitic stainless steel were evaluated. An analysis of the tribological behavior, as well as basic mechanical properties at the small scale can deepen the understanding of the effects of cryogenic treatments in steel alloys.Conventionally treated specimens (CHT) were subjected to a quenching and annealing treatment, while the deep cryogenicall treated (DCT) samples were quenched, soaked in liquid nitrogen for 2 h and annealed. Hardness, hardening coefficient and elastic recovery of the materials were assesed by nanoindentation tests under displacement control, while the friction behavior and wear rate were evaluated by means of nanoscratch tests. Both sets of experiments were performed using a Hysitron TI950 triboindenter.It was found that cryogenic treatments improved hardness, increased the hardening coefficient and exhibited less worn volume and friction than conventionally treated ones. A correlation between the tribological behavior at the nano and the macroscopic scale could be inferred.