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In this study, ultra-high-strength steels, namely, cold-hardened austenitic stainless steel AISI 301 and martensitic abrasion-resistant steel AR600, as base metals (BMs) were butt-welded using a disk laser to evaluate the microstructure, mechanical properties, and effect of post-weld heat treatment (PWHT) at 250 °C of the dissimilar joints. The welding processes were conducted at different energy inputs (EIs; 50–320 J/mm). The microstructural evolution of the fusion zones (FZ) in the welded joints was examined using electron backscattering diffraction (EBSD) and laser scanning confocal microscopy. The hardness profiles across the weldments and tensile properties of the as-welded joints and the corresponding PWHT joints were measured using a microhardness tester and universal material testing equipment. The EBSD results showed that the microstructures of the welded joints were relatively similar since the microstructure of the FZ was composed of a lath martensite matrix with a small fraction of austenite. The welded structure exhibited significantly higher microhardness at the lower EIs of 50 and 100 J/mm (640 HV). However, tempered martensite was promoted at the high EI of 320 J/mm, significantly reducing the hardness of the FZ to 520 HV. The mechanical tensile properties were considerably affected by the EI of the as-welded joints. Moreover, the PWHT enhanced the tensile properties by increasing the deformation capacity due to promoting the tempered martensite in the FZ.

Medium carbon high-silicon abrasion resistant (AR) steel was examined by performing dilatometry, light optical microscopy (LOM), scanning electron microscopy (SEM), and hardness measurements after isothermal bainitization and modified martempering and compared to direct quenching technology. A commercial thermodynamic tool was used for hardness prediction and compared to the measured one and revealed a rather good agreement for direct quenching, as was the case for isothermal holdings near to the martensite start (Ms). The predicted martensite start temperatures were in good agreement with the experimental data, the experimental value was 321 °C, while the predicted values were 324 and 296 °C. However, a higher discrepancy appeared for isothermal holding much above the martensite transition in the bainite region resulting in lower measured hardness compared to the predictions related to the actual kinetics and complexity of the formed final volume percentages of phase constituents such as bainite, martensite, and rest austenite, later as a part of unfinished bainite transformation at studied temperature. The predicted hardness values for quenching, isothermal holding at 280, 300 and 350 °C were 50.6, 50.6, 49.4 and 49.4 HRC, while the measured values were 53.3, 48.3, 48 and 43 HRC, respectively. A very good agreement between the thermodynamic prediction was achieved by comparing the measured Ms concerning prior austenite grain size as one of the crucial parameters for setting a proper heat treatment strategy of various isothermal quenchings making thermodynamic predictions for low alloyed steels a powerful tool for optimizing the heat-treating operations.

This paper investigates the effect of the energy input on the microstructure evolution and mechanical properties of laser-welded dissimilar lap joints of cold work-hardened austenitic stainless steel (CW-ASS) and martensitic abrasion resistant steel (AR600). Microstructure characterization of the welds was conducted using optical microscopy and electron backscatter diffraction in a scanning electron microscope. Subsequently, the mechanical properties of the dissimilar lap joints were determined using microhardness measurements and tensile tests. The microstructure observations show that the phase structure in the fusion zone (FZ) is predominantly ferritic at both energy inputs. Besides, the solidification microstructure in the FZ resembles the cast structure composed of cellular and columnar dendrites with exhibiting elemental segregations. The hardness reaches its peak in the FZ. However, the FZ near AR600 steel exhibited higher hardness values than that near CW-ASS. The dissimilar lap joints welded at low energy input 160 J/mm achieved a higher shear strength than those welded at high energy input 320 J/mm due to the softening of the weld in the former lap joint.

The paper investigates experimentally the usability of ultra-high-strength stainless steel and abrasion resistant steel in laser-welded sandwich structures. The fatigue and shear strength of laser joints were investigated using lap joints that were welded using two very different energy inputs. Also the effect of multiple weld tracks was investigated. The properties of separate laser welds were characterized by hardness testing and optical microscopy. Results of the hardness measurements showed that there was softened area at heat-affected-zone and weld metal of the ultra-high-strength stainless steel welds. AR steels weld metal was harder than base metal and there was softened zone in heat-affected-zone of the weld. The shear strength of tested single weld joints of the ultra-high-strength stainless steel was higher compared abrasion resistant steel single weld joints, but stronger joint can be made with multiple weld seams for abrasion resistant steel. Fatigue strength of investigated ultra-high-strength stainless steel lap joint was lower than fatigue strength of abrasion resistant steel lap joint in the low-cycle regime, but there was no practical difference in fatigue limit (10e7 cycles).

The effect of processing parameters such as hot rolling and heat treatment on microstructure and mechanical properties was investigated for a new 0.27mass% C and Ni, Mo-free low alloy martensitic abrasion resistant steel. The three-body impact abrasive wear behavior was also analyzed. The results showed that two-step controlled rolling besides quenching at 880 ℃ and tempering at 170 ℃ could result in optimal mechanical property., the Brinell hardness, tensile strength, elongation and --40 ℃ impact toughness were 531, 1530 MPa, 11.8% and 58 J, re- spectively. The microstructure was of fine lath martensite with little retained austenite. Three-body impact abrasive wear results showed that wear mechanism was mainly of plastic deformation fatigue when the impact energy was 2 J, and the relative wear resistance was 1.04 times higher than that of the same grade compared steel under the same working condition. The optimal hardness and toughness match was the main reason of higher wear resistance.

Abrasive wear due to particles sliding along a surface (two-body abrasion) or in between two surfaces (three-body abrasion) often leads to early failure of machine components exposed to, e.g., slurry, sand, wear debris, and so on. The primary cause for failure due to abrasive wear is the interaction between abrasive particles and the material surface. Simulation of an entire abrasive system is complicated and involves several challenges. Therefore, a single scratch test is the most fundamental and simplest abstraction of abrasive wear that can be simulated using finite-element modeling (FEM). A novel load-controlled quasi-static explicit three-dimensional (3D) scratch model has been developed using ABAQUS (6.14) for the current study. The FE model was validated using experimentally performed scratch tests on an abrasion-resistant martensitic steel. The influence of load and indenter geometry on scratch geometry was studied in detail. Future work will focus on introducing damage and strain rate dependent material behavior into the model in order to deepen the understanding of the interaction between an abrasive and the material.

Light alloys are being increasingly investigated as alternatives to ferrous-based engineering components, based on weight considerations. However, in-service applications of such light alloy components often require a surface modification step to enhance their wear and corrosion responses for improved functionality. Thermally sprayed cermet coatings offer an enhanced resistance to wear and corrosion. This work investigates WC-CoCr coatings deposited using two different feedstocks comprising fine and coarse powder size distributions on aluminum alloy and steel substrates using high-velocity air-fuel (HVAF) and high-velocity oxy-fuel (HVOF) spray techniques. The WC-CoCr coatings were HVAF sprayed at various parameters to investigate the relationship between the processing conditions, microstructure, and performance. Microindentation, dry sliding wear, dry sand abrasion, cavitation erosion, and corrosion tests were conducted to assess the performance of the coatings. Despite the qualitative similarities in the microstructures of the coatings, the measured microindentation hardness values were observed to vary, and coatings deposited with higher particle impact velocities showed the highest microhardness between 1400 and 1600 HV0.3. For the three categories of wear investigated, the HVAF coatings showed better resistance than the HVOF coating investigated in this study. The estimated average specific wear rate (SWR) due to sliding wear of the HVOF coating was ~ 16.7 ± 4.0 × 10 −8  mm 3 /Nm compared to that of the most resistant HVAF coating, which exhibited a SWR of ~ 1.7 ± 0.6 × 10 −8  mm 3 /Nm. The cumulative mass loss rate due to the abrasive wear on the HVOF coating reached ~ 1.11 mg/min compared to ~ 0.76 mg/min of the most abrasion-resistant HVAF coating. All coatings showed similar corrosion resistances under the investigated conditions. The combination of wear and corrosion performance of the respective coatings could provide insight into the coating selection for intended applications.

To mitigate the detrimental effects of water on metal textiles, hydrophobic modification of such materials has garnered significant attention. However, traditional approaches often rely on complex procedures or costly materials, limiting their widespread application. Herein, we present a facile method for fabricating a superhydrophobic coating on steel mesh, and characterize the properties of the modified material. Initially, the surface of the dry steel mesh is uniformly coated with nano-ZnO crystals using a liquid deposition technique at room temperature. Subsequently, stearic acid is employed to hydrophobically modify the ZnO crystals, yielding a ZnO-based superhydrophobic coating. The influence of ZnO concentration and deposition duration on the surface crystal structure, hydrophobicity, and abrasion resistance is investigated. X-ray diffraction (XRD) analysis is performed to study the surface groups before and after hydrophobic modification, while static contact angle measurements are used to assess the hydrophobic properties of the coated surface. Remarkably, even after abrasion with 1000-mesh sandpaper, the superhydrophobic properties of the steel mesh with an optimized ZnO concentration decrease by only 4%. This simple, cost-effective, and highly efficient preparation method holds promising potential for applications in related fields.

This paper presents the results of wear tests of two types of commercial low-carbon, low-alloy martensitic abrasion-resistant steels, Hardox 450 and XAR 450, which belong to the hardness class 450 HBW. These steels, due to their increased resistance to the abrasive wear mechanism, are used for machine parts for applications in intensive abrasion environments such as construction, mining, and agriculture. The scope of work included microstructure analysis on an optical microscope, chemical composition analysis, Vickers hardness measurements at different loads (HV0.2, HV1 and HV2), and wear testing. Wear tests were carried out by the standard method “dry sand—rubber wheel”, and tests on the Taber abrader device. Microstructure analysis revealed that both steels have a similar non-oriented, homogenous, fine-grained martensitic microstructure. The results of HV2 hardness measurements showed a similar trend for both steels in all examined sections of the plates. For both tested steels, the hardness values of HV0.2 and HV1 are slightly higher than HV2, but the scattering of the results is also greater. Abrasion resistance testing using the standard “dry sand—rubber wheel” method showed that Hardox 450 steel has a lower volume loss of about 8%, but a greater scattering of the results compared to XAR 450 steel. The results of the abrasion resistance test on the Taber abrader device confirmed approximately the same behavior. For both steels, a prediction model was established for a reliable assessment of the wear intensity concerning the grain size. Although examined steels belong to the same hardness class, Hardox steel seems to be a more appropriate choice for the manufacture of machine components exposed to abrasive wear.

In this study, multi-element nitride coatings composed of (Ti, Cr, Cu, Al, Si)N were synthesized on H13 tool steel using cathodic arc deposition (CAD) technology. The N2/Ar flow ratio varied from 0 to 2 as the experimental parameter, and two targets, Ti-Cr-Cu and Al-Si alloys, were utilized simultaneously. The impact of the gas flow ratio on the coatings’ abrasion properties was investigated, focusing on aspects, such as chemical composition, adhesion, hardness, and wear behavior. The experimental findings indicate that the coated specimens with a nitrogen reaction exhibit superior hardness and abrasion resistance compared to those without nitrogen use. While the surface roughness of the specimens tends to increase slightly with a higher N2/Ar ratio, the coating demonstrates improved hardness, adhesion, and abrasion resistance performance. In summary, the wear-resistant characteristics of H13 tool steel can be significantly enhanced when applying a CAD-(Ti, Cr, Cu, Al, Si)N film with a flow ratio of N2/Ar = 2.