Effect of Nanobainite Content on the Dry Sliding Wear Behavior of an Al-Alloyed High Carbon Steel with Nanobainitic Microstructure

Abstract

In this work, a multiphase microstructure consisting of nanobainte, martensite, undissolved spherical carbide, and retained blocky austenite has been prepared in an Al-alloyed high carbon steel. The effect of the amount of nanobainite on the dry sliding wear behavior of the steel is studied using a pin-on-disc tester with loads ranging from 25–75 N. The results show that, there is no significant differences in specific wear rate (SWR) for samples with various amounts of nanobainite when the normal load is 25 N. While, the SWR firstly decreases and then increases with increasing the amount of nanobainite, and the optimum wear resistance is obtained for samples with 60 vol.% nanobainite, when the applied load increases to 50 and 75 N. The improved wear resistance is attributed to the peak hardness increment resulted from the transformation of retained austenite to martensite, work hardening, along with amorphization and nanocrystallization of the worn surface. In addition, the highest toughness of the samples with 60 vol.% nanobainite is also proven to play a positive role in resisting sliding wear. EDS (energy dispersion spectrum) and XRD (X-ray diffraction) examinations reveal that the predominant failure mechanism is oxidative wear.

Abrasive Wear Behavior of Cryogenically Treated Boron Steel (30MnCrB4) Used for Rotavator Blades

“…From the results drawn in Figure 7, it is clear that hardness increased in the specimens CHT (215.76%), CDCT-T0 (260.73%), CDCT-T1 (216.60%), CDCT-T2 (197.42%), and CDCT-T3 (179.19%), as compared to UT sample. The maximum improvement in the hardness was observed in CDCT-T0 sample due to conversion of RA into martensite and formation of secondary carbides after deep cryogenic treatment [57,[59][60][61].…”

Effect of fretting wear on TC4 alloy prepared by laser shock peening at high temperature

“…As shown in Figure 12, the friction contact area was covered by a black oxide burning layer formed by grinding particles and mechanical rolling. 29 Subsurface sprouting cracks caused by the slippery edges of the contact area intersected with the surface cracks, accumulating plastic strain energy at the viscous–slip boundary and leading to laminar detachment. In the contact centre, where adhesion was weakened and removed, strips of spalling and flakes formed along the fretting direction.…”

Tribocorrosion of nanocrystalline 42NiSiMo8-3-7-F steel

“…Relatively high amount of soft retained austenite in carburised layer and low in the core affects lesser difference between layer and core hardness which was particularly observable for sample after nanobainitisation. It is worth noticing that modern heat treatment of nanobainitisation or B-Q&P despite resulting in comparable or lower hardness of steel than conventional quenching and tempering, due to possible TRIP (Transformation Induced Plasticity) effect in blocks of retained austenite may exhibit higher strength, ductility and wear resistance [1][2][3]12,13]. Conducted microhardness measurements were sufficient only for rough estimation of depth of carburised layer to be 1.6 mm.…”

“…Sample submitted to B-Q&P with multiphase microstructure had slightly lower surface hardness. Lowest hardness in whole cross section of carburised layer was measured for steel sample after nanobainitisation, which can be caused by high content of retained austenite and insufficient microstructure refinement [12,13]. It is worth noticing that difference between hardness on cross section of samples after quenching and tempering and after B-Q&P is negligible.…”