Borided AISI Research Articles

Finite element analysis of sliding wear on the borided AISI 316L stainless steel

This work implements a 3D finite element to analyze wear in borided AISI 316 L stainless steel. The 3D model was validated through sliding wear test under a ball-on-flat configuration, following the ASTM G133 standard procedures. ABAQUS software was used with an Arbitrary Lagrangian-Eulerian (ALE) remeshing technique alongside the UMESHMOTION subroutine to apply an elemental level Archard’s equation. The artificial roughening of the worn surfaces due to discretization in finite element sizes was controlled by relating the maximum increment time on each wear step to the element size and the stroke. The study also described the evolution of the stress field and the behavior of the contact area. The maximum stress was estimated after the first indentation, decreasing as the contact area increased, reaching a minimum at the last wear step. The results revealed a good correlation between the experimental and modeled data, with a maximum error of 8.34% in the contact stress and a maximum error of 22% in the wear depth.

Growth kinetics of Fe2B layer formed on the surface of borided AISI M2 high-speed steel

Abstract In this study, the growth kinetics of the Fe2B layer was investigated and formed on the surface of borided AISI M2 high-speed steel. Boriding treatments carried out by the pack-boriding method were carried out using Ekabor 2 boriding agent at 1,173, 1,273, and 1,373 K for 2, 4, and 6 h. After the boriding processes, the samples were prepared metallographically and their microstructures were examined with the help of backscattered electrons (BE) by scanning electron microscope (SEM). Following SEM examinations, microhardness measurements were carried out from a single sample using 100 g with the Vickers indentation method to understand whether the layer hardness was compatible with Fe2B. When the results of the experimental studies are compared with the results of the literature, it has been determined that AISI M2 high-speed steel can be borided and the boride layer formed on the surface is single-phased (Fe2B), unlike that formed on many other steel types. After determining that the layer formed on the borided AISI M2 surface is single-phase Fe2B, the growth kinetics calculations of this phase were carried out with the help of the Arrhenius equation.

Influence of boriding on the tribological behavior of AISI D2 tool steel for dry deep drawing of stainless steel and aluminum

Deep drawing of stainless steel and aluminum is a widely adopted method for manufacturing various industrial goods. However, the wear damage produced to die tools is a recurring problem in these processes. While lubricants are often employed to lubricate and reduce die wear, dry deep drawing is the current best alternative for meeting green manufacturing demands. Hence, enhanced solid lubricants or surface treatments for dies are highly required. This study aims to evaluate and compare the tribological behavior of a heat-treated AISI D2 steel and a boriding AISI D2 tool steel against stainless steel (AISI 304) and aluminum alloy (AA 6061 T6) in the absence of lubricant. The boride coating was formed on the AISI D2 steel by the closed-pack boriding technique, resulting in a tooth-saw morphology with an overall thickness of 33.6 μm. X-ray diffraction analysis confirmed the presence of FeB, Fe2B, and Cr2B3 phases on the surface of the borided AISI D2 tool steel. Notably, the boriding treatment led to a significant increase in the surface hardness of the tool steel, reaching a value of 20.7 GPa. The coefficient of friction (CoF) behavior and wear were evaluated by pin-on-disk tests, simulating conditions similar to those found in cold deep drawing operations. The wear surfaces were analyzed by optical profilometry and scanning electron microscopy (SEM). The results suggest boriding as a suitable treatment to reduce wear damage on the surface of deep drawing dies used for stainless steel and aluminum forming processes in the absence of lubricant. Two-body abrasion and adhesion were identified as the main wear mechanisms in AISI D2 steel against stainless steel and aluminum, with a significant amount of oxidation observed when aluminum was tested. Additionally, a reduction of approximately 20 % in the CoF was observed when employing borided tool steel against stainless steel. However, there was an observed increase of around 75 % in the CoF when the borided tool steel was tested against aluminum.

Chemical Species Formed on FeB-Fe2B Layers during Wet Sliding Wear Test

In the present work, X-ray photoelectron spectroscopy (XPS) survey spectra of borided AISI 316L for two different times (1 and 6 h) of exposure to simulated body fluid (SBF) were obtained after wet sliding wear. A borided layer of ~39 microns was obtained on the surface of the AISI 316L stainless steel using the thermochemical treatment of boriding. As part of the mechanical and chemical characterization of sliding wear, Berkovich nanoindentation and X-ray spectroscopy tests were used to determine the main properties of the borided layer. The results of the specific wear rate values were higher at 5 mm/s sliding speed than those recorded at 30 mm/s due to the influence of the exposure time of the sample and the complex combinations of chemical reactions with boron (e.g., B2S3, Cr2O3, and Fe2O3) on the surface during the sliding during 6 h of exposure in Hank’s solution due to the formation of the passive film. The knowledge of chemical species formed during wet sliding wear tests on borided AISI 316L is essential for understanding wear mechanisms and materials’ performance and optimizing material properties and materials’ and components’ reliability in the biomedical industry for screws and fastening plates.

Statistical significance of the sliding wear test parameters under lubricated conditions on borided AISI 316 L-SS samples

This article presents new findings related to the assessment of wear test parameters, including material, load, and sliding speed, focusing on understanding the statistical characteristics of response variables such as width, depth, wear volume, specific wear rate, and coefficient of friction. Wet sliding wear tests were conducted on both borided and non-borided AISI 316 L-SS samples under controlled environmental conditions. The tests were developed using the ASTM G133–05 standard guidelines and UMT-2 tribological equipment. The results of the variance analysis revealed that the material factor exhibited the most substantial statistical significance for width, depth, wear volume, specific wear rate, and CoF, accounting for 91.4%, 88.1%, 86.3%, 79.4%, and 78.8% of the variance, respectively, followed by the normal load factor. The response variables behavior was analyzed through the Surface Response Methodology statistical technique, and the approach equations were obtained.

Solid particle erosion resistance of borided AISI D2 steel

Powder-pack boriding process was conducted on AISI D2 tool steel to improve its solid particle erosion resistance when compared to hardened and tempered (H&T) AISI D2 steel. FeB and Fe2B layers with thicknesses of 49 ± 6 μm and 44 ± 7 μm, respectively, were obtained. Erosion resistance was evaluated at different impingement angles at room temperature (RT) and 400 ºC using alumina particles. Novel results show that borided AISI D2 steel performs significantly better than H&T AISI D2 steel at impingement angles of 15º, 30º and 60º at both RT and 400 ºC, with reductions up to 81% in mass loss. However, at 90º, mass loss for borided AISI D2 steel is significantly higher. Mass loss in H&T AISI D2 steel is generated by progressive cutting and microforging, whereas in the borided AISI D2 steel it is generated by cracking and fracture.

Tribochemical products on borided AISI 316L steel exposed to Hank's solution

In the biomedical industry, the AISI 316L steel has been widely used due to its biocompatibility and low cost. However, an undesired effect of the wear and corrosion influenced by operational conditions is the reaction of the tissue to the metal, generated by replacements of the biomedical components such as screws and fixing plates. In this work, the evolution of the chemical species formed on the surface of the borided and non-borided AISI 316L steels during wet sliding conditions using a simulated body fluid (SBF Hank's solution) was investigated with the aim to improve the wear performance of the AISI 316L steel exposed to a boriding process. The results revealed that the specific wear rate of the borided AISI 316L steel was ∼3 times lower than that of the non-borided AISI 316L steel under the same wet sliding conditions. Also, the corrosion and wear resistance of both steels are related to combinations of reaction productions such as B2S3, Cr2O3, and Fe2O3 during sliding wear by the formation of a passive layer, according to the results obtained by XPS, which reduced the specific wear rate. Finally, adhesive, abrasive, and tribo-oxidative wear modes were observed in both steels, with grooving, material agglomeration, plastic deformation, and passive film as the main wear mechanisms.

Comparative Study of Conventional and Microwave-Assisted Boriding of AISI 1040 and AISI 4140 Steels

In this study, AISI 1040 and AISI 4140 steels were boriding using Ekabor-II commercial boriding powder with powder-pack boriding method using microwave and conventional heating methods. The samples were borided at 950 °C for 2 and 6 hours in an Ar atmosphere in a microwave oven of Enerzi-Mh2912-V8. Biphasic structure (FeB/Fe2B) was formed in all borided AISI 4140 samples and AISI 1040 samples borided for 6 hours. A single-phase structure was observed in AISI 1040 steel borided for 2 hours. Compared to the conventional method, a 1.5-1.6 times thicker boride layer was obtained in AISI 4140 and AISI 1040 steels with microwave-assisted powder-pack boriding. The highest hardness was measured as 1561.8 HV0.05 for boriding AISI 4140 steel and 1499.7 HV0.05 for boriding AISI 1040 steel. The Vickers indentation fracture toughness of borided steels with microwave energy varied between 2.31 and 3.46 MPa·m1/2. It was determined that in all samples borided by the microwave-assisted and conventional powder-pack boriding method, the adhesion strength between the boride layers and the substrate obtained was sufficient.

Sliding Wear Resistance of Borided AISI 4140 Steel

Sliding Wear Resistance of Borided AISI 4140 Steel

Adhesion behaviour of borided AISI 4140 steel

ABSTRACT In this study, the adhesion behaviour of the borided AISI 4140 steel was estimated. A di-iron boride layer (Fe2B = ∼22 µm) was obtained on the surface of the AISI 4140 steel preheated at 773 K for 30 min to prevent thermal shock; afterwards, the samples were exposed to 1173 K for 30 min. The scratch tests were developed over the surface of the Fe2B/substrate system using a Rockwell-C diamond indenter with a normal force increasing from 0.5–80 N. The friction coefficient behaviour and the residual depth values were measured considering the scratch length that was monitored during the test, according to the ASTM C1624 standard procedure. Critical loads were determined through the combination of the normal force and visual inspection over the worn surface with cracks (cohesive failure) or detachment (adhesive failure) and are explained according to the mechanical properties of the Fe2B/substrate system.

Dry and grease-lubricated reciprocating wear resistance of borided AISI 52100 steel

This work presents new results about the dry and grease-lubricated wear resistance of borided AISI 52100 steel. Boriding was conducted at 850 °C for 1 h. The reciprocating wear tests were conducted with an alumina ball of 6 mm of diameter, with normal load of 20 N and sliding distances of 100, 150 and 200 m; a lithium grease was employed for lubrication. In comparison with heat-treated AISI 52100 steel, boriding reduced the coefficient of friction by 15–30% in dry conditions, although both stabilized similarly in grease-lubricated tests. In addition, the results showed that, for the longer sliding distance, boriding increased the wear resistance up to 8 times in dry conditions and up to 10 times using grease for lubrication. The implementation of boriding significantly improved the tribological performance of AISI 52100 steel in both tests conditions.

Tribological and adhesion properties of microwave-assisted borided AISI 316L steel

Abstract In this study, AISI 316L stainless steel alloy samples were borided with powder-pack boriding method using Ekabor II powder with the support of a microwave furnace with a power of 2.9 KW and a frequency of 2.45 GHz. Boriding was carried out at 850, 900 and 950 °C temperatures for 2, 4 and 6 h of operation. A distinct diffusion barrier consisting of Fe–Ni–Si elements was detected in borided samples at 950 °C for 4 and 6 h. As a result of the Daimler Benz Rockwell-C adhesion tests, regions with insufficient adhesion strength were detected in these samples. In other samples, adhesion qualities between boride layers and substrate were in the range of HF1–HF3. The lowest specific wear rates were determined as 5.208 (mm3 Nm−1) × 10−6 and 5.210 (mm3 Nm−1) × 10−6 for the samples borided for 6 h at 850 °C and 4 h at 900 °C, respectively. It was determined that the increase in thickness of the brittle FeB compound increased the wear with the three-body abrasive wear mechanism.

Scratch test in boride layers: Influence of indenter tip radius on failure mechanisms

In this work, the influence of indenter tip radius (ITR) on scratch tests in boride layers was studied. The thermochemical treatment of boriding was performed on an AISI H13 steel at 1000 °C for 1 h. Depth sensing indentation test was developed to estimate both, hardness, and elastic modulus of the boride-layer/substrate system. Indenter radius of 200, 100, 50 and 20 μm were used for the scratch tests on borided steel. Failure mechanisms were analyzed by scanning electron microscopy (SEM). Predominant failure mechanisms were lateral cracking, chipping, and gross chipping. ITR of 20 μm developed more severe damage on the borided AISI H13 surface and the more severe substrate plastic deformation was obtained by ITR of 200 μm.

Microstructure and mechanical properties of borided AISI T1 high-speed steel by dehydrated paste-pack boriding

Microstructure and mechanical properties of borided AISI T1 high-speed steel by dehydrated paste-pack boriding

Development of tribological maps on borided AISI 316L stainless steel under ball-on-flat wet sliding conditions

Tribological maps on powder-pack borided and non-borided AISI 316L steel under a Hank’s solution medium, during linear reciprocating sliding wear tests with a ball-on-flat configuration, are presented with the aim of elucidating the role of the operating environment on wear mechanisms and tribological performance. 2D maps obtained by Response Surface Methodology showed the coefficient of friction, wear volume and specific wear rate as a function of load and sliding speed. Findings showed k for the non-borided AISI 316L steel was between 5.40 and 34.90 ×10−6 mm3/Nm, while it was between 2.37 and 4.91 ×10−6 mm3/Nm for the borided AISI 316L steel. Grooving, smearing, plastic deformation and the formation of a passive film were the identified wear mechanisms on the wear tracks using Scanning Electron Microscopy.

Investigation of mechanical, kinetic and corrosion properties of borided AISI 304, AISI 420 and AISI 430

ABSTRACT In this study, three different types of stainless steels, AISI 304, AISI 420, and AISI 430 were pack borided under 850 °C–925 °C–1000 °C for 2, 4, and 6 h, respectively. Morphologies of coating were investigated by optical and scanning electron microscope (SEM). The maximum layer hardness was determined to be 1736 HV0.05, 1659 HV0.05, and 1572 HV0.05 for AISI 304, AISI 420, and AISI 430, respectively. Phases formed on the layer were determined by X-ray analysis (XRD) to confirm the presence of FeB, Fe2B, CrB, and MnB phases. Boride layer morphology was found to be a planar and compact structure. The activation energies of the coating were investigated. The corrosion resistance values of stainless steels were determined from the static immersion tests performed in 10% HCl solution. There was a remarkable increase in the corrosion resistance of borided steel compared to that of untreated samples.

Dry sliding wear test on borided AISI 316L stainless steel under ball-on-flat configuration: A statistical analysis

In this paper, significant results about the evaluation of the influence of wear test factors such as load, distance, and sliding speed are analyzed to determine the statistical behavior of the specific wear rate, depth, and friction coefficient as response variables. Dry sliding wear tests were performed on the borided AISI 316L stainless steel under controlled environmental conditions, according to the ASTM G133-05 standard procedure, and a UMT-2 universal tester was used. The development of the analysis of variance showed that the load factor has the major statistical significance on the specific wear rate, depth, and CoF with 63.7%, 59.60%, and 62.67%, respectively. The response surface methodology was applied through the distance weighted least-squares fitting to explain the behavior of the response variables on the measured variables and the difference in the performance due to the total distance of sliding.

Sliding wear analysis in borided AISI 316L steels

In this study a numerical-experimental evaluation of the sliding wear resistance of iron boride layers formed on the surface of an AISI 316L steel was developed. The boriding process was carried out at a temperature of 900 °C for 2 h and 6 h of exposure. Pin-on-disc tests were realized on non-borided and borided AISI 316L steels. The experimental results showed that the boriding contributed significantly to the wear resistance of the AISI 316L steel compared to the non-borided material. In addition, the thinner boride layer thickness developed more severe wear mechanisms. Finally, principal stresses and maximum shear stress generated in the layer/substrate systems were evaluated during the wear test using the finite element method (FEM).

Wear maps of borided AISI 316L steel under ball-on-flat dry sliding conditions

New results on wear maps of borided AISI 316L steel, obtained by powder-pack boriding process, are presented to provide a general visualization of its wear performance under different dry sliding conditions. Wear maps showed wear behavior in terms of specific wear rate, volume of material removed and coefficient of friction as a function of load (5–20 N) and sliding speed (5–30 mm/s). Specific wear rates between 5 × 10−6 to 9.7 × 10−6 mm3/Nm were found, corresponding to mild wear and the transition region to severe wear. Grooving, material agglomeration and the formation of a tribofilm characterize the mild zone as observed by SEM-EDS, while debris, pitting and severe grooving predominate in the transition zone.

Friction and wear of borided AISI O1 steel with carbon nanomaterial deposit

Carbon nanomaterials (CNs) were deposited on borided AISI O1 steel by chemical vapor deposition. The deposit, characterized by scanning electron microscopy and X-ray diffraction, presents CNs such as carbon nanotubes, as well as cementite and amorphous carbon. The tribological effects of friction and wear under dry conditions were analyzed with a ball-on-disk with a tungsten carbide (CW) ball and roughness meter. The results show that the coefficient of friction considerably decreases and stabilizes to ~ 0.24 for the sample with CNs. It also is concluded that CNs act as a protective coating that prevents the surface of the borided steel from wear.