Scratch resistances of compacted graphite iron with plasma nitriding, laser hardening, and duplex surface treatments

The effect of graphite number per area on tribological behavior of high-strength compacted cast irons in lubricated tests

“…With the sum of the percentage of ZDDP elements seen in Figure 6, it is easier to verify that the tribofilm formation was more intense for GJV450, which is related to the higher level of deformation that happened in this material. Other investigations [7,14,19] showed a higher sum of (Zn+P+S), meaning that in the current investigation the formation of tribofilms was not significant to determine the average COF values. For example, Wollmann et al [6] determined 10% of (Zn+P+S) for rings manufactured in austempered CGI, while the same authors [14] verified almost the same value for GJV450 using 170N load for cylinder samples.…”

“…Friction behavior is a combination of multiple interactions between tribo-elements. In reference [7] three significant aspects for friction were discussed, to explain a compensating effect that resulted in similar values: i) plastic deformation, ii) ejection of graphites, and iii) tribofilm formation. Considering the sum (Zn+P+S) as indicative of tribofilm formation, this aspect can be considered less significant, as previously discussed.…”

“…In this sense, different strategies have been used to improve even more the mechanical properties. Among them, we can cite the austempering heat treatment [5,6], combined surface treatments [7], shallow nitriding [8], induction hardening [9], and the addition of alloying elements [10] are also good options that have been studied to improve the surface properties of graphite irons.…”

Effect of austempering treatment on lubricated sliding contact of compacted graphite iron

“…These excellent combined mechanical, physical, and tribological properties of CGI are associated with the graphite particles' inter-connected coral-like morphology between nodular and lamellar shapes. Some strategies have been adopted to improve wear resistance of the CGI alloys, using the laser hardening technique [7], the addition of pearlitic stabilizer elements [8], surface alloying [9], and induction hardening [10]. Another possible route for increasing mechanical properties is austempering heat treatment.…”

Low Frictional MoS2/WS2/FineLPN Hybrid Layers on Nodular Iron

“…It improves the friction coefficient of the surface layer as well as its resistance against hydrogen wear both at dry and lubricated regime [24][25][26][27][28]. More intricate is the issue of cast iron nitriding, due to the presence of graphite precipitation in the microstructure [29,30] Recently, the new non-equilibrium, low-pressure nitriding process (FineLPN) has been developed. It may be used for creation of fully controlled phase structure of nitrided case both on steel and cast iron due to dedicated neural network computer support [31].…”