Wear Mechanism Of Steel Research Articles

Precipitation Refinement via Aging Time Modification for Enhancing Wear Resistance in Ti–V–Nb Microalloyed High‐Manganese Steels

It is imperative to ensure an even distribution of refined precipitates to enhance wear resistance. Herein, different heat treatments are to control the size and distribution of precipitates. The treatments include water quenching at 1100 °C followed by aging at 400 °C for 24, 60, and 84 h, designated as AT24, AT60, and AT84, respectively. The microstructure, mechanical properties, and impact wear properties of high‐manganese steel are investigated under solution and aging conditions using scanning electron microscopy, field‐emission scanning electron microscopy, tensile testing, and impact abrasive wear testing. Notably, the absence of nanoscale precipitates largely accounts for the poor wear resistance of as‐casting steel, whereas the strengthening effect of larger micrometer‐sized precipitates is insufficient. After the solution and aging treatment, nanosized precipitates continuously form within the matrix, conducive to the formation of the deeper work‐hardening layer, thereby improving the wear resistance. The fine micrometer‐sized precipitates and evenly distributed nanoscale precipitates in AT60 actively contribute to toughness. Additionally, these precipitates interact with slip dislocations, providing stronger strengthening via the Orowan looping mechanism. The wear mechanisms of steel can be transformed from wide, deep pits to shallow grooves and microcutting by extending the aging time.

Effect of cutting parameters on tool life during end milling of AISI 4340 under MQL condition

PurposeThe purpose of this paper is to study the cutting performance of high-speed regime end milling of AISI 4340 by investigating the tool life and wear mechanism of steel using the minimum quantity lubrication (MQL) technique to deliver the cutting fluid.Design/methodology/approachThe experiments were designed using Taguchi L9 orthogonal array with the parameters chosen: cutting speed (between 300 and 400 m/min), feed rate (between 0.15 and 0.3 mm/tooth), axial depth of cut (between 0.5 and 0.7 mm) and radial depth of cut (between 0.3 and 0.7 mm). Toolmaker microscope, optical microscope and Hitachi SU3500 Variable Pressure Scanning Electron Microscope used to measure tool wear progression and wear mechanism.FindingsCutting speed 65.36%, radial depth of cut 24.06% and feed rate 6.28% are the cutting parameters that contribute the most to the rate of tool life. The study of the tool wear mechanism revealed that the oxide layer was observed during lower and high cutting speeds. The former provides a cushion of the protective layer while later reduce the surface hardness of the coated toolOriginality/valueA high-speed regime is usually carried out in dry conditions which can shorten the tool life and accelerate the tool wear. Thus, this research is important as it investigates how the use of MQL and cutting parameters can prolong the usage of tool life and at the same time to achieve a sustainable manufacturing process.

Study of the three-body impact abrasive wear behaviour of a low alloy steel reinforced with niobium

In order to improve the wear resistance of steel, a new Nb-added reinforced low-alloy wear-resistant steel was developed, and the wear behavior of the three-body impact abrasive was systematically studied under the impact energy of 0.5J, 2.5J, 4J, 5J. Tensile testing, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and nanoindentation were used to characterize the mechanical properties, microstructure evolution and wear mechanism of steel. The experimental results show that NB05 (0.05 wt%-Nb) steel with smaller size lath martensite has higher strength performance and better impact wear resistance than NB0 (0 wt%-Nb) steel. During three-body impact abrasive wear tests, the corrected wear rate was less under higher impact energy for both steels, and the NB05 steel owned less wear rate than NB0. The main strengthening mechanisms of the wear layer were newly formed martensite twins, niobium precipitates, high density dislocations and the formation of nanoscale grains for the NB05 steel. The wear mechanism of the wear layer is mainly reflected in buffering, lubrication and protection of debris.

Structure and Wear Resistance of Nitrocarburized Medium-Carbon Steels

The methods of optical and scanning electron microscopy are used to study the structure and phase composition of nitrocarburized layer in medium-carbon steels alloyed with manganese, chromium and nickel. Transmission electron microscopy is applied to study the structure of the heterophase zone and to determine its phase composition. The wear resistance and the wear mechanism of steels of different alloying systems are determined.

Epsilon carbide precipitation and wear behaviour of low alloy wear resistant steels

In this study, we obtained different morphology and size of epsilon carbides (ϵ-carbides) via low temperature tempering of 0.32 wt-% C low alloy wear resistance steel. The objective is to elucidate the determining role of size and morphology of carbides on mechanical properties and three-body impact wear resistance. The formation of small needle-like ϵ-carbides was responsible for increase in yield strength, low temperature impact toughness and three-body impact wear resistance. However, when the ϵ-carbides were large and rod-like, hardness, toughness and three-body impact wear resistance were significantly reduced. The wear mechanism of steel containing needle-like ϵ-carbides primarily involved plastic deformation associated with fatigue and small degree of abrasive wear and furrow, while steels containing rod-like ϵ-carbides were predominantly characterised by furrow.

Effects of the tribo-oxide and matrix on dry sliding wear characteristics and mechanisms of a cast steel

The dry sliding wear tests were performed at the ambient temperature range of 25–400 °C on a pin-on-disc configuration for a cast steel with various tempered microstructures. The effects of the tribo-oxide and matrix on the dry sliding wear behaviors were investigated and wear mechanisms were explored. The wear behaviors and wear mechanisms of the steel were found to be closely related with the tribo-oxide and matrix. With an increase in the ambient temperature and load, the amount of tribo-oxides increased, but the subsurface matrix softened for high-hardness microstructure and workhardened for low-hardness microstructure. Tribo-oxides reduced wear on a prerequisite that matrix retained certain strength to support tribo-oxide layer, otherwise they did not provide the protection against wear. For the tempered martensite and tempered troostite, trace or a small amount of tribo-oxides would relatively reduce the wear rate of adhesive wear. A small amount of tribo-oxides formed at 200 °C totally prevented intermetallic contact, mild oxidative wear prevailed. However, as the matrix was soft (tempered sorbite) or softened at elevated-temperature, tribo-oxides could not reduce wear; the oxidative wear was beyond mild oxidative wear, even the plastic extrusion wear prevailed.

Mechanisms of wear of steel by natural rubber in water medium

The wear mechanisms of steel by natural rubber (NR) in water medium were investigated. The surface profile, element constitutions and binding energies of the surfaces for both steel and rubber have been analyzed with scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), respectively. Moreover, the functional groups of natural rubber surfaces were examined with Fourier transform infrared spectrometer (FT-IR). It has been found that the processes of wear of steel by NR involve two stages. Firstly, under the action of frictional forces, some mechanochemical reactions generated among the surfaces of steel and rubber as well as the water medium, which produced a chemical reaction film on the steel surface. Secondly, this film was destroyed and removed by the microcutting action of the debris on the sliding surface, as a result the steel surface wore off. The wear mechanisms might be mainly attributed to the chemistry–mechanics self-catalytic destruction mechanism of steel being rubbed by natural rubber.

Effect of Thermochemical Treatments on the Sliding Wear Mechanisms of Steels Under Boundary Lubrication

The effect of heat treatment, carburizing and plasma nitriding on the material-removal mechanisms and wear behavior of steels under boundary-lubricated conditions has been studied. A controlled procedure using mild abrasives under a light load was adopted in order to avoid long-term effects from severe wear in the running-in stage of pin-on-disc testing. Electron microscopy of the sliding surfaces showed that wear of the untreated steel took place by abrasive and adhesive mechanisms. Heat treatment by austenitizing, quenching and tempering (through-hardening) reduced the wear rate and carburizing produced a further reduction. The principal wear mechanisms in the both through-hardened and carburized steels was abrasive and delamination wear with adhesive wear being unimportant. Electron microscopy on cross-sections through the sliding surfaces of the carburized and through hardened steels showed extensive plasticity, cracks, and delaminated wear phenomena. The elimination of adhesive wear as a major wear mechanism is attributed to the influence of hardness on junction growth and the emergence of delamination wear to the effect of nano-crystalline carbides on fatigue life. Plasma nitriding resulted in an additional reduction in wear rate and the effective elimination of delamination wear. Electron microscopy on the plasma-nitrided steel revealed the presence of a dispersion of white layer regions, which raised the yield strength but also - resulted in micro-pitting due to a deformation mismatch with the matrix. Presented as a Society of Tribologists and Lubrication Engineers paper at the World Tribology Congress in London, United Kingdom, September 8–12, 1997

Nature of impact-abrasive wear of steel

The wear mechanism of steel from the standpoint of the thermofluctuation theory of fracture is considered. A model of the intensity of impact-abrasive wear of steel is presented, taking into account the impact self-action and the thermofluctuation properties of the material. Justification is given for the study of tribotechnical problems including the foundations of strength physics.