Impact-abrasive Wear Resistance Research Articles

Effect of retained austenite on impact-abrasion wear performance of high-strength wear-resistant steel prepared by dynamic partitioning process

The ductility and toughness of the high-strength wear-resistant steels can be improved by introducing retained austenite. However, the influence of retained austenite on the impact-abrasion wear resistance remains uncertain. This study investigates the effect of retained austenite on the impact wear performance of martensitic wear-resistant steel by introducing 5.2–9.2 vol% retained austenite through the dynamic partitioning (DP) process. The results display that the microstructures of the various DP-treated steels primarily consist of lath martensite and film-like retained austenite distributed between martensite laths. The three-dimensional atom probe (3DAP) analysis demonstrates that the retained austenite exhibits a significantly higher carbon concentration than the martensite, with carbon enrichment increasing gradually from the edge to the core of the retained austenite. In short-term impact wear tests (10 min), the weight loss of DP-treated steels is inversely proportional to the volume fraction of retained austenite. Conversely, in the long-term impact wear tests (20–90 min), it is positively proportional to the volume fraction of retained austenite. Initially, the strain-induced martensite transformed from retained austenite can absorb more impact energy, passivate the crack, and inhibit crack propagation, which is the dominant factor contributing to improved wear resistance. However, as impact wear progresses, the detrimental effects arising from the high hardness and poor plastic deformation ability of the strain-induced martensite become dominant, accelerating crack propagation during long-term impact wear tests. This study may provide insights into the microstructure design of the martensitic wear-resistant steels under impact wear conditions, specifically regarding the role of retained austenite.

Microstructure and abrasive wear performance of a novel CALPHAD-inspired wear-resistant steel containing multiphase and multiscale carbides

The microstructure and abrasive wear performance of a novel wear-resistant steel designed based on the CALPHAD approach were characterized and evaluated. The steel exhibited distinct improvements over conventional high chromium cast iron through the precipitation of micron-sized M7C3 carbides from austenite via desolation transformation, resulting in a more uniform distribution with smaller sizes and desirable shapes. Moreover, the steel incorporated micron-sized carbides (M7C3, VC, and Mo2C) and submicron carbides (M7C3 and VC) as hard reinforcing phases, while nano-sized carbides (Mo2C, M7C3, and M3C) contributed to dispersion hardening. The wear resistance and impact-abrasive wear resistance of the steel were 1.8 times and 1.7 times superior to that of KmTBCr26 under identical wear conditions, respectively. These results indicated that the modified features of the micron-sized M7C3 carbides effectively mitigated undesirable phenomena such as cracking and spalling during the wear process, leading to improved impact-abrasive wear resistance in this steel. The exceptional wear resistance was attributed to the synergistic effect of multiphase and multiscale carbides, demonstrating the effectiveness and potential of CALPHAD-inspired design strategies in developing advanced wear-resistant materials.

Особливості структуроутворення в економнолегованих хромомарганцевих залізовуглецевих сплавах для гірничо-металургійного обладнання

It was established that in cast chromium-manganese alloys of the transition class Fe–C–Mn–Cr system (carbon content no more than 2.2%) with a certain combination of Mn and Cr, the formation of crystals of highly hard carbide Me7C3 is possible. The relationship between the phase-concentration parameters and the structure formation of alloys of the Fe–C–Mn–Cr system was studied, the analysis of the relationship between the phase-concentration parameters, structure formation and properties was carried out on the compositions of the Fe–C–Mn and Fe–C– Mn–Cr with 1.5-2.1% C, with a variable content of Mn, Cr and additives of other alloying elements - Si and Ni at the level of impurities. A phase-concentration diagram of the crystallization of the alloys of this system was constructed, delimiting the regions of crystallization P → γ-Fe, P → γ-Fe + Me3C and P →(γ -Fe + Me7C3) + (γ-Fe + Me3C). It is shown that economically alloyed chromium-manganese alloys of the Fe–Mn–Cr–C system with eutectics based on Me7C3 carbide are characterized by a high level of shock-abrasive wear resistance, and the results of the conducted studies indicate the prospects of using economically alloyed chromium-manganese alloys and can be recommended for further research and use as wear-resistant materials for the manufacture of parts of replaceable metallurgical equipment, which are operated in severe conditions of abrasive and shock-abrasive wear. Keywords: phase-concentration diagram, microstructure, Me7C3 carbide, impact-abrasive wear resistance, chromium-manganese alloys

Impact-abrasive wear resistance of high alumina ceramics and ZTA

In transport of raw materials abrasive wear resistance is a requirement, which can be met with alumina ceramics. At certain locations additional impact load occurs, exacerbating the wear loss. As literature on impact-abrasive wear of ceramics is scarce this topic will be researched in this work.We selected a variety of commercial alumina ceramics (90–96% Al2O3) and according to literature much more impact resistant – and substantially more expensive – Zirconia Toughened Alumina (ZTA, 20–25% Zr) used for wear resistant linings in impact dominated systems. We selected the Impeller-Tumbler test, an impact-abrasion test for wear evaluation of highly loaded ceramic edges. Two load regimes were evaluated for the abrasive, either corundum particles for severe load or steel balls for extreme load conditions. Correlation of wear results with the fracture toughness (K1C) and Vickers hardness of the materials is intended – material parameters used as measure for brittle failure of ceramics and wear resistance, respectively.The various ceramic materials showed very different wear behaviour under the impact-abrasive load. The 90% Al2O3 was least wear resistant under both load conditions. Interestingly large differences between the 92% types were found at extreme load conditions. The increase of alumina content to 95–96% showed remarkable benefits in both wear regimes. Best wear resistance against severe load was achieved by 25% ZTA, while it is comparable to the 95–96% high alumina types at extreme load.

How the micro-mechanical stability of carbides in chromium-rich hardfacings influences the impact-abrasion resistance at elevated temperatures

Highly loaded wear components in applications such as crushers or sieves suffer from combined impact and abrasive wear, in the worst case exaggerated by high operation temperatures. Hardfacings based on the system FeCrC with high hardphase contents are promising candidates for such applications. Understanding of the influence of precipitated carbides or carbo-borides on the impact-abrasive wear resistance is therefore of high importance to increase the lifetime, decrease downtime as well as maintenance costs.In this study, two different FeCrC-based hardfacings were chosen for investigation, an FeCrC-alloy and a complex alloyed FeCrNbMoBC type. A thorough microstructural analysis was performed via scanning electron microscopy. Here, present hardphases, namely chromium carbides, chromium carbo-borides as well as niobium carbides were found. To evaluate the hardness H and Young's modulus E nanoindentation measurements were performed and the plasticity indicating ratios H/E and H³/E2 were derived. Scratch tests at elevated temperatures were performed identifying critical loads for carbide displacement and fracture. Those critical loads as well as the plasticity indexing parameters were correlated with the impact-abrasion behaviour of the two hardfacings via high-temperature cyclic impact abrasion tests up to 500 °C. Results showed higher impact-abrasion resistance of the complex-alloyed FeCrC-based hardfacing due to better stability of the carbides as well as optimal ratios H/E and H³/E2 indicating increased plasticity and thereby better impact resistance.

Effect of strength and toughness of ceramic particles on impact abrasive wear resistance of iron matrix composites

The wear resistance of ceramic particle reinforced metal matrix composites is closely related to the properties of ceramic particles. In this study, three kinds of ceramic particle (with 30 % volume fraction) reinforced iron matrix composites (Al2O3/Fe45, ZTA(Zirconia toughened alumina ceramic particles)/Fe45 and ZrO2/Fe45) were prepared by powder metallurgy method. The mechanical properties, impact abrasive wear resistance and impact abrasive wear mechanism of the composites were studied, and the phase transformation of ceramic particles in the composites was analyzed. The results show that the elastic modulus and hardness of ZTA/Fe45 composite are between Al2O3/Fe45 and ZrO2/Fe45, which are 248.5 GPa and 13.3 GPa, respectively. The ZTA/Fe45 composites exhibit a better impact wear resistance than the other two composites. The impact abrasive wear resistance of the three kinds of composites is positively correlated with the product value of fracture toughness and hardness (H·KIC) of ceramic particles. The wear mechanism of the Fe45 matrix of the composite is micro-furrow and plastic deformation. The brittle fracture and spalling of Al2O3 ceramic particles occur after impact abrasive wear, forming spalling pits and accelerating the wear of Al2O3/Fe45 composites. ZrO2 ceramic particles lead to easy removal from the Fe45 matrix due to lower hardness after impact abrasive wear. ZTA ceramic particles protruded from the surface of the Fe45 matrix after impact abrasive wear. On the surface of ZTA particle, the irregular protuberant steps morphology are formed by SiO2 abrasive impact and tangential wear. The ZTA and ZrO2 ceramic particles in the worn surfaces of the composites undergo t-ZrO2 to m-ZrO2 phase transformation during the impact wear, and the t→m phase transformation content is related to the impact energy. The amount of phase transition increases with the increase of impact energy, When the impact energy is higher than 2J, the amount of phase transition tends to be stable. Under the same impact energy, the amount of t→m phase transition in ZrO2 particles is much lower than that in ZTA. The t→m phase transformation increases the toughness of ZTA particle，improving the impact abrasive wear resistance of ZTA/Fe45 composite.

Impact abrasive wear behaviour of the multiphase microstructure in a medium carbon quenched and partitioned bainitic steel

To enhance the impact abrasive wear resistance of steel for mining and metallurgy industries, a 0.3C steel with a multiphase microstructure of bainitic, martensitic and retained austenite was produced by a Q&P process involving bainitic transformation, and its wear performance under impact abrasive conditions was evaluated in contrast with fully martensitic and fully bainitic steels. The results revealed that the multiphase microstructure demonstrates outstanding combination of strength (1612 MPa), toughness (105 J), hardness (48.7 HRC) and elongation (19.2%), along with superior impact abrasive wear resistance. After 90 min of impact abrasive wear test, the multiphase microstructure shows lower wear loss than that for the fully martensitic and fully bainitic steels, which can be attributed to its high surface microhardness and increased toughness. The formation of nanograins and an increase in dislocation density as well as the retained austenite transformation leads to the higher surface microhardness. In addition, some larger craters can be observed on the wear surface of fully martensitic and fully bainitic steels, and the crack propagation depth is larger under the wear surface. In contrast, the wear surface of the multiphase microstructure presents some delamination damage, and the crack propagation depth is shallow because of the thicker deformed layer and presence of film-like austenite retained in the deformed microstructure. These results suggested that the multiphase microstructure can be used as a potential candidate structure for enhanced resistance to impact abrasive wear.

Effect of microstructure transformation below MS temperature in bainitic steels on the impact-abrasive wear behavior

The bainitic steel austempered below MS (martensite start temperature) with good strength and toughness has a great potential in the field of wear resistance. In this paper, the impact abrasive wear resistance of bainitic steel austempered below MS temperature was studied and compared with those of bainitic steel austempered above MS temperature. The results show that the wear resistance of bainitic steel austempered below MS is better than that of bainitic steel austempered above MS. The wear mechanism of bainitic steel austempered below MS is dominated by fatigue wear. This is attributed to the refinement of bainitic ferrite laths and martensite-retained austenite blocks by austempering processes below MS. The bainite steel austempered below MS with higher initial hardness can effectively resist the impact load and the damage of abrasive particles to the wear surface, thereby reducing the wear weight loss.

Effect of TiC on the impact abrasive wear resistance of low alloy martensitic steel

The effect of TiC on the impact abrasive wear (IAW) resistance of low alloy martensitic steel was investigated by comparing the abrasive wear (AW) and IAW behaviours of JFE400 (without carbides) and Ti60 (with 3.25 % TiC). Under AW conditions, weight loss is mainly caused by abrasive wear. Under IAW condition, fatigue cracks are formed at the interface of deformed layer (DL) / matrix in the worn subsurface. Abrasive and delamination wear are responsible for weight loss. In addition to weaken the abrasive microploughing, TiC can also inhibit the formation of DL composed of nanosized grains by dynamic recrystallisation, thereby preventing fatigue crack propagation. Therefore, the relative wear resistance of Ti60/JFE400 increased from 1.38 (AW) to 1.60 (IAW).

Microstructure and Wear Characterization of the Fe-Mo-B-C-Based Hardfacing Alloys Deposited by Flux-Cored Arc Welding.

An analysis of common reinforcement methods of machine parts and theoretical bases for the selection of their chemical composition were carried out. Prospects for using flux-cored arc welding (FCAW) to restore and increase the wear resistance of machine parts in industries such as metallurgy, agricultural, wood processing, and oil industry were presented. It is noted that conventional series electrodes made of tungsten carbide are expensive, which limits their widespread use in some industries. The scope of this work includes the development of the chemical composition of tungsten-free hardfacing alloys based on the Fe-Mo-B-C system and hardfacing technology and the investigation of the microstructure and the mechanical properties of the developed hardfacing alloys. The composition of the hardfacing alloys was developed by extending the Fe-Mo-B-C system with Ti and Mn. The determination of wear resistance under abrasion and impact-abrasion wear test conditions and the hardness measurement by means of indentation and SEM analysis of the microstructures was completed. The results obtained show that the use of pure metal powders as starting components for electrodes based on the Fe-Mo-B-C system leads to the formation of a wear-resistant phase Fe(Mo,B)2 during FCAW. The addition of Ti and Mn results in a significant increase in abrasion and impact-abrasion wear resistance by 1.2 and 1.3 times, respectively.

Impact Abrasive Wear Resistance of CrN and CrAlN Coatings

The impact wear resistance of the hard coating is very important in the high-temperature environment of the nuclear power plant. CrN and CrAlN coatings were prepared using multi-arc ion plating. The impact abrasive wear resistance of the coatings was investigated at varied temperatures through a controlled kinetic energy impact wear rig, and their impact mechanism was elucidated. No extensive spalling was found on the surface of the CrN and CrAlN coatings after 104 impacts under the no-sand condition. The excellent antioxidant properties of the CrN and CrAlN coatings can protect the substrate from oxidation under the no-sand condition at 500 °C. The impact mechanism of the two coatings was plastic deformation under the no-sand condition, and it was mainly material removal under the sand condition. The depth and width of wear scar were larger under the sand condition than under the no-sand condition. The impact wear region was divided into a mixed impact zone and a sand impact zone. Compared with the CrN coating, the CrAlN coating had lower impact force and shallower impact wear scar, proving that it has better anti-impact wear properties.

The Effect of Cooling Rate on Structure, Basic Mechanical and Special Properties of Complex Alloyed Manganese Cast Iron

The results of the study of the cooling rate effect on the structure and properties of castings for parts of equipment made of complex alloyed manganese cast iron, which operate under conditions of abrasive and impact-abrasive wear, are presented. The properties and characteristics of microstructures of samples from the investigated cast iron composition for different cooling rates are given: relative and impact-abrasive wear resistance, hardness, volume fraction of the carbide phase, and the average size of carbides. It is shown that the cooling rate (as well as the chemical composition of cast iron) is a determining factor in the primary microstructure formation that affects the properties of castings.

Impact and abrasion wear resistance of the hardfacings based on high-manganese steel reinforced with multicomponent carbides of Ti-Nb-Mo-V-C system

Structure formation and impact-abrasion wear resistance of the hardfaced layers deposited by flux-cored arc welding with powder wires of a high-manganese austenitic steel – (Ti, Nb, Mo, V)C high-entropy(-like) carbide system, were investigated and compared to the impact-abrasion resistance of the commercially available high-manganese steel-based hardfacing as well as with high-speed and mild carbon steels. Flux for the flux-cored wires was prepared by adding the equimolar mixture of TiC, NbC, VC and Mo2C powders to the Si-alloyed ferromanganese and arc shielding components. Microstructure investigations of the hardfaced layers show, that its structure consists of an austenitic matrix and complex carbide reinforcements, in form of uniformly distributed fine-grained particles. Its impact-abrasion wear resistance is more than three times higher than that for hardfacing, deposited with commercially available high-manganese steel-based electrodes and almost equal to the high-speed steel samples tested under the same conditions.

Research and Comparative Analysis of Wear Resistance of Cast Grinding Media From Chromium Cast Irons

A study was made of the impact-abrasive wear resistance and impact resistance of grinding bodies cast in a multi-place mold. Three types of chromium cast irons were adopted for the study: low chromium (~1% Cr), medium chromium (up to 5% Cr) and high chromium (up to 20% Cr). The macro- and microstructure of these alloys as a material for cast grinding balls has been studied. Installed an increase in the impact-abrasive wear resistance and impact resistance of such products with an increase in the mass fraction of chromium in cast iron due to the formation of carbides of the (Fe, Cr)3C and especially (Fe, Cr)7C3. Balls were cast in multi-seat chill molds. Cast iron was smelted in a medium-frequency induction furnace, such as IChT, with the main lining on a charge of pure pig iron and steel low-carbon scrap. The temperature of cast iron production was 1500 °C. Liquid cast iron was subjected to alloying with medium carbon ferrochrome. The wear resistance of cast irons was determined on samples cut from balls in the radial direction. The tests were performed in a laboratory mill When tested for impact resistance, the grinding ball received a striking blow of mass 50 kg, falling from a height of 0,5 m. The frequency of application of dynamic loads was 10 beats per minute. Impact resistance was determined by the average number of impacts sustained by the grinding body prior to destruction. Nevertheless, significant excess of the cost high-chromium over low-chromium cast iron forces us to agree with the opinion of the majority of researchers and the practice of production of such metal products. In today's conditions, low-chromium white cast iron is an economically viable material for grinding media.

Influence of compositions and heat treatment on metastability of structure and properties of wear-resistant cast irons of the Fe-Cr-Mn-C system

The influence of chromium, manganese, carbon content and quenching modes on the formation of the structure, metastability of austenite and properties wear-resistant cast iron alloying system Fe-Cr-Mn-C with small additions of titanium, copper, silicon in various variations was investigated. The metallographic, durometric research methods, tests for dynamic bending, impact-abrasive wear resistance were applied. The regularities of changes in the phase composition and microstructure under the influence of the heating temperature for quenching in the range from 920 to 1070 °C with cooling in sand have been established. With an increase in the heating temperature for quenching in the structure of cast irons, the content of austenite increases and the content of quenching martensite decreases. The amount of carbide phases of compositions (Fe, Cr)3C, (Cr, Fe)7C3, (Cr, Fe)23C6 and titanium carbonitrides TiCN, depending on the content of carbon and alloying elements, as well as the heating temperature for quenching, varies within 20...35 %. A significant contribution of deformation induced phase transformations - martensitic, dynamic aging, occurring in the surface layers in the process of testing in the formation of impact-abrasive wear resistance of cast irons was revealed. It is characterized by the effects of deformation self-hardening, manifested in the increase in the hardness of the surface (working) layer within HRC = 2...9 and relaxation of microstresses. The formation of optimal martensitic-austenitic-carbide metastable structure could be provided at the optimal ratio of alloying elements and under the influence of heat treatment at which the effect of deformation self-hardening at wear that increases drastically the wear resistance of the investigated cast irons could be realized. The developed cast irons of optimal compositions have shown high economic efficiency in the production of working bodies of shot-blast machines, sand-throwers, protective lining plates of sintering-blast furnace equipment. They can be recommended for the manufacture of various high-wear machine parts of machines operating under conditions of impact-abrasive andabrasive wear.

Sintering Preparation of 15 wt% Cr Cast Iron as well as Its Mechanical Properties and Impact Abrasive Wear

15 wt% Cr sintered High Chromium Cast Iron (HCCI) with full density was successfully prepared by Super-solidus Liquid Phase Sintering (SPLS) technique, with water atomized 15 wt% Cr high chromium cast iron powder as initial materials. Its densification behavior and microstructure evolution in SPLS process and mechanical properties were investigated systematically. Additionally, the impact abrasive wear resistance under different impact energies were also analyzed and compared with another sintered HCCI with 20 wt% Cr. The results indicated that sintering temperature has a strong influence on the sintered alloy’s density, hardness, impact toughness and bending strength. The M7C3 type (M is Cr and Fe) carbides were obviously coarsened as temperature increased and their rod-shaped branches were fully developed at the same time, thereby resulting in carbide network formation in the matrix. The reasonable sintering temperature range was 1195–1205 °C, and the optimum mechanical properties had the hardness of 63.9 HRC, bending strength of 2112.65 MPa and impact toughness of 7.92 J/cm2. What is more important impact abrasive wear test results indicated 15 wt% Cr sintered HCCI’s wear resistance could be comparable to 20 wt% Cr sintered HCCI under impact energy 1~3 J/cm2, and it is more cost effective.

The Role of Distribution Forms of Fe-Cr-C Cladding Layer in the Impact Abrasive Wear Performance of Hadfield Steel.

To investigate the role of different distribution forms of Fe–Cr–C cladding layer in the impact abrasive wear performance of Hadfield steel, the over-lapped Fe–Cr–C cladding layer and dot-shaped Fe–Cr–C cladding layer were deposited, respectively, by plasma transferred arc (PTA) cladding on Hadfield steel. The microstructure, microhardness and impact abrasive wear performance of the two cladding layers under the impact of glass sand, granite and quartz sand were investigated. The results showed that both microstructures of the cladding layers were hypoeutectic Fe–Cr–C microstructures. The average microhardness of the over-lapped cladding layer and dot-shaped cladding layer was around 560 HV0.2 and 750 HV0.2, respectively. The over-lapped Fe–Cr–C cladding layer could only improve the impact abrasive wear resistance of the Hadfield steel under the wear condition of the glass sand. Meanwhile, the dot-shaped Fe–Cr–C cladding layer could improve the impact abrasive wear resistance of the Hadfield steel under all the three kinds of the abrasives because of the overall strengthening effect of its convex shape and the hypoeutectic FeCrC microstructure.

Comparative study on microstructures and properties of Mn-containing and Mn-free bainitic steels

ABSTRACT The effects of Mn on the microstructure and impact-abrasion wear resistance of bainitic steel were studied. Results showed that the Mn-containing steel possessed finer microstructure and higher volume fraction of retained austenite, in comparison with the Mn-free steel. This was caused by lower transformation temperature and higher strength of undercooled austenite. The weight loss of Mn-free steel varying with the impact load was larger than that of Mn-containing steel. High strength, hardness and toughness of Mn-containing steel were conducive to improving wear resistance. More retained austenite in Mn-containing steel played an active role in work hardening and hindering crack propagation. However, the portion of retained austenite that induced martensitic transformation was the same with increasing impact-wear load.

Influence of Ni content on impact-abrasion wear resistance of medium-carbon low alloy cast steel

Medium-carbon low alloy wear-resistant cast steel with different Ni contents (0.08 mass%, 0.77 mass%, 1.74 mass%, 2.43 mass%) were heat treated at 1050 °C, followed by water quenching and tempering at 250 °C. The influence of Ni content on the microstructure, hardness, impact toughness and abrasive resistance of the cast steel were investigated. The results showed that the Ni contents increasing hindered the transformation of martensite phase by reducing martensite transformation start temperature (Ms) and martensite transformation finish temperature (Mf). The fine martensite phase after quenching improved the hardness, impact toughness and wear-resistance of the cast steel. The cast steel with low Ni content (0.08% or 0.77%) consists of lath tempered martensite, while the microstructure turns to mixed lath martensite and lamellar twin martensite with higher Ni content. The cast steel with 1.74% Ni showed a hardness of HRC49.5, an impact absorbing energy with V-notch impact absorbing energy of 16.7 J, and the best wear resistance among the samples.

Fabrication and interaction mechanism of Ni-encapsulated ZrO2-toughened Al2O3 powders reinforced high manganese steel composites

In order to solve the cast-infiltration difficulty and low interface bonding strength of ZrO2-toughened Al2O3 (ZTA) powders reinforced high manganese steel (HMS) matrix composite, uniform and continuous Ni-encapsulated ZTA powders (ZTAp@Ni) as reinforced phase are fabricated by electroless deposition assisted with ionic liquid additive. The effects of Ethaline concentration, temperature, ZTA concentration and deposition times on the morphology of ZTAp@Ni have been investigated. Experimental results show that the thickness of Ni coating is about 7–10 μm, and there is no casting crack or shrink on the composite, so compact bonding between ceramic and matrix is obtained. In addition, the impact abrasive wear resistance testing demonstrates that the performance of ZTAp@Ni reinforced HMS composite is superior to that of matrix. On the basis of experimental analysis, a schematic illustration of the cast-infiltration process is put forward. It implies that Ni-encapsulated ZTA can be wetted with molten HMS matrix to form a ZTA/Al2NiO4-Al2MnO4/Fe interface layer through Ni diffusion and reactive wetting. The interdiffusion of Ni and other elements at ZTA interface layer can reinforce the interfacial bonding strength to form an interface layer between metal and hard phases.