Alloy Steel Research Articles

Increased secretion of bacterial pyomelanin caused by light accelerates corrosion of low alloy steel.

Microorganisms in the waterline zone can secrete pigments to avoid damage caused by ultraviolet radiation, some of which have corrosive effects. In this work, we found that the secretion of pyomelanin by P3 strain of Pseudoalteromonas lipolytica significantly increases under strong lighting conditions, accelerating the corrosion of the material. Molecular mechanisms indicate that strong light, as a stressful environmental factor, enhances the expression of melanin secretion-related genes to prevent bacteria from being damaged by ultraviolet radiation. Therefore, this work proposes a new corrosion mechanism in the waterline zone, pigment-producing microorganisms are also involved in the waterline corrosion process.

Enrichment of epoxy coating on amalgamation with corrosion-resistant poly (2,3-benzopyrrole)/zinc oxide nanoflowers (PBZNF) synthesized composite for carbon steel alloy featuring excellent hydrophobicity

Enrichment of epoxy coating on amalgamation with corrosion-resistant poly (2,3-benzopyrrole)/zinc oxide nanoflowers (PBZNF) synthesized composite for carbon steel alloy featuring excellent hydrophobicity

Cutting force and surface roughness evaluation of cryogenic treated inserts for machining en24 grade alloy steel: RSM modelling approach

Cutting force and surface roughness evaluation of cryogenic treated inserts for machining en24 grade alloy steel: RSM modelling approach

NiCrBSi/WC Composite Claddings Processed on AISI 316L Steel Alloy by the Direct Laser Deposition Process: Studies on Dry Sliding Wear Behavior and Wear Mechanism Maps

Abstract This study presented the wear behavior of the NiCrBSi/WC composite claddings processed on an AISI 316L steel alloy substrate by laser cladding approach. The scanning electron microscope (SEM) morphology of the claddings has shown excellent substrate–cladding interface bonding, good WC particulate distribution, and no noticeable cracks and voids. The electron dispersion spectroscope (EDS) spectra have confirmed the presence of respective NiCrBSi alloy matrix and WC elements. The XRD spectra have identified various phases and compounds such as gamma-Ni, FeNi3, Ni3B, Cr23C6, Ni3Si, and W2C commonly in all the processed composite claddings. The microhardness of the claddings was measured between 791 and 1086 HV0.2 for increasing the reinforcement WC particulate percentage from 15 wt% to 60 wt%. It is about 470% surface hardness enhancement with the processed composite claddings compared with the substrate alloy. The reinforcement of WC from 15 wt% to 60 wt% with the composite claddings resulted in wear resistance enhancement from 21.85% to 60.64% and the coefficient of friction from 56.87% to 77.92% against the substrate. The wear-rate maps and their respective cladding's worn surface morphology have described the wear mechanisms typically as adhesive, abrasive, oxidation, and delamination. The wear mechanisms are mainly influenced by the WC particulate percentage. The increased WC particulate content has increased the dominance of the abrasive wear mechanism while reducing the window of the adhesive wear mechanism. The windows of various wear mechanisms and their ranges, such as adhesive 0.0033 to 0.028, abrasion 0.010 to 0.067, oxidation 0.012 to 0.093, and delamination 0.015 to 0.120 mm3/m, for NiCrBSi/WC composite claddings comprehensibly represented the wear behavior for the varied conditions of dry sliding wear parameters.

Experimental Analysis of Spiral Finishing Process on EDM Drilled Hole in Titanium

It is quite evident that some of the experimental research works have been carried out by researchers in the area of spiral polishing using abrasive for surface finishing improvement but most of the experiment has been employed on Steel or Alloy Steel as a material. Very few number of research works have been performed by researchers across the globe on the Spiral Polishing Method of Titanium holes made by Electrical Discharge Machining (EDM). Therefore, experimental investigations were carried out in the area of Spiral Polishing and Finishing of EDM-drilled holes of various materials to meet the desired goal of demands on the surface quality. This experimentation aims to develop a novel method with spiral polishing using abrasive flow finishing. To explore the search investigation and find out the better surface finishing for through holes made on EDM, the process parameters have been designed using the Taguchi L16 orthogonal array with input parameters such as Current (I), Pulse on time (Ton), and Pulse off time (Toff). The addition of Boron Carbide Powder with Handwash, Glycerine, Shampoo, and Liquid Soap is used to decrease the Surface Roughness (Ra) with a ratio of 5 : 1. The Taguchi technique is used to assess the P/M process parameter setting for a given signal to noise (S/N) ratio.

Investigation of the transient change of the cutting force during the milling of C45 and X5CrNi18-10 steel taking into account the dynamics of the electro-mechanical measuring system

AbstractThe possible methods of determining the cutting force—due to the great practical importance of knowing the force—have long been and are still intensively studied areas of cutting theory. In milling, cutting is a series of successive short material removals. During force measurement in such cases, the transient process that can be detected at the beginning of the process can influence the nature of the entire cutting cycle. The present study reports on the research, the aim of which was to explore the dynamic process of cutting force measurement in intermittent cutting. The measurements were made during face milling of C-steel and highly alloyed steel (X5CrNi 18–10). The milling head contained a single insert, with which the disturbing interaction of the multiple cutting edges was eliminated. As a result of the work, a method suitable for examining the close relationship between the initial transient nature of the milling cycle and the decay, as well as a mathematical model for the decay process, was developed. The model was validated with cutting experiments and measurements. The achieved results can be used to better understand the process of chip removal and to determine the actual power requirements of milling works.

Enhanced corrosion resistance of 9Cr alloy steel via Al alloying in simulated harsh marine atmosphere

The corrosion behaviors of Cr9Ni1 and Cr9Ni1Al in simulated harsh marine atmosphere were studied by dry-wet cyclic test (DWCT). Scanning electron microscopy (SEM), energy disperse spectroscopy (EDS) and electron probe microanalyzer (EPMA) were used to observe the cross-section morphology of rust layer. The composition of corrosion products were analyzed through X-ray diffractometer (XRD) and X-Photoelectron spectroscope (XPS). Electrochemical impedance spectroscopy (EIS) was used to determine the electrochemical properties of rusted samples. The results show that the corrosion rate of both 9Cr alloy steels increases continuously during the initial corrosion process of 576 h, which can be understood from α/γ*>1 of the rust layer and the acidification caused by increased CrO3. Interestingly, the addition of 0.7 % Al reduced the corrosion rate of 9Cr steel by more than 26 %. Al not only generates Al2O3 and Al(OH)3 enriched in the whole rust layer, but also optimizes the rust layer in terms of the Cr distribution, composition of Cr-containing compounds, and α-FeOOH content. Importantly, it is proposed that Al alloying weakens acidification through reducing CrO3 content and partial dissolution of the generated Al(OH)3.

Study on Galvanic Corrosion Behavior of AH36 Steel and TC4 Alloy Processed by Plasma Electrolytic Oxidation

Study on Galvanic Corrosion Behavior of AH36 Steel and TC4 Alloy Processed by Plasma Electrolytic Oxidation

Effect of Temperature and Concentration on the Corrosion Behavior of 42CrMoE Low Alloy Steel in Boric Acid Solution

Effect of Temperature and Concentration on the Corrosion Behavior of 42CrMoE Low Alloy Steel in Boric Acid Solution

Effect of single and double pulse laser-induced breakdown spectroscopy towards steel alloy in different gaseous media

In recent years, laser-induced breakdown spectroscopy (LIBS) technique showed its promising for material analysis, quality control, forensic science, and environmental safety monitoring. Besides, due to its rapid measurement capability and minimal sample-preparation requirements, it is a widely recognized elemental analysis approach used in a variety of study domains. The current work compares spatially resolved single (SP) and double pulse (DP), especially orthogonal DP, setups for LIBS to examine and enhance the limit of detection (LOD) in duplex stainless steels alloy. Using the Boltzmann plot method and the Stark broadening mechanism, the electron temperature and density of local arc plasma are highlighted due to single pulse and orthogonal pre-pulse double pulse configurations. With delay time, the circumstances of arc plasma's local thermodynamic equilibrium (LTE) of emission spectral lines are investigated. The experimental results show that there are significant increases in the spectral intensities of the Fe lines in double pulse LIBS under Ar-gas compared to those under He-gas. Internal standardization was used to create calibration curves for the spectral lines of Cr, Cu, and Mn in the alloy sample for the both studied media. It demonstrated that argon outperforms helium in determining the elemental composition of steel alloys. Furthermore, LOD for SP-LIBS and DP-LIBS in both media were calculated, which showed a higher detection LOD for DP-LIBS in the presence of Ar-gas compared to that in He-gas.

Effect of alloy 625 buffer layer on corrosion resistance of nickel base hardfacing

Nickel base hardfacing alloys serve to mitigate corrosion losses at elevated temperatures. Efficacy of Nickel base hardfacing alloys can be compromised when applied onto Fe base substrates due to iron dilution in hardfacing. The degree of Fe dilution can be reduced by using advanced deposition methods and optimized deposition parameters. Gas Tungsten Arc Welding (GTAW) method is commonly employed for its cost-effectiveness and versatility, but it tends to induce higher Fe dilution due to increased heat input. This study aims to reduce the degree of Fe dilution and enhance corrosion resistance by introducing a nickel base buffer layer (alloy 625) between the nickel base hardfacing alloy and AISI 316L stainless steel substrate. For comparative purposes, Ni base hardfacing alloy was deposited on the substrate without any buffer layer. Hardfacing depositions were prepared using manual GTAW process. Process parameters namely, deposition current, voltage, travelling speed, pre-heating temperature, and cooling method were kept constant. Samples underwent aging at 1123 K for 4 h, followed by microstructural examination via optical and scanning electron microscopes. Iron (Fe) dilution quantification was performed using energy dispersive spectroscopy (EDS). The EDS analysis showed that the use of buffer layer between the hardfaced deposit and the substrate decreased the degree of Fe dilution in the hardfaced deposit. X-Ray diffraction (XRD) analysis was performed to identify various phases formed in the hardfaced deposit. Potentiodynamic polarization test was performed to assess the corrosion resistance of hardfaced deposit in 3.5 wt% NaCl solution. Results show significant improvement in corrosion resistance of hardfacings deposited sample with buffer layer as compared to those without buffer layer. Aging treatment further enhanced corrosion resistance. The corrosion resistance data is correlated with the microstructure and phases formed in various samples.

Uncertainty quantification in multivariable regression for material property prediction with Bayesian neural networks

With the increased use of data-driven approaches and machine learning-based methods in material science, the importance of reliable uncertainty quantification (UQ) of the predicted variables for informed decision-making cannot be overstated. UQ in material property prediction poses unique challenges, including multi-scale and multi-physics nature of materials, intricate interactions between numerous factors, limited availability of large curated datasets, etc. In this work, we introduce a physics-informed Bayesian Neural Networks (BNNs) approach for UQ, which integrates knowledge from governing laws in materials to guide the models toward physically consistent predictions. To evaluate the approach, we present case studies for predicting the creep rupture life of steel alloys. Experimental validation with three datasets of creep tests demonstrates that this method produces point predictions and uncertainty estimations that are competitive or exceed the performance of conventional UQ methods such as Gaussian Process Regression. Additionally, we evaluate the suitability of employing UQ in an active learning scenario and report competitive performance. The most promising framework for creep life prediction is BNNs based on Markov Chain Monte Carlo approximation of the posterior distribution of network parameters, as it provided more reliable results in comparison to BNNs based on variational inference approximation or related NNs with probabilistic outputs.

Fretting wear behaviour of high strength alloy steel induced by plasma nitriding and post-oxidation

Fretting wear is caused by a relative movement of the material surface on a small scale. Finding ways to reduce fretting wear is of great importance for extending equipment life and reducing maintenance costs. With the increase of load, the effecrt of fretting wear adhesion of surface treated material becomes more obvious. The materials treated with post-oxidation have stronger wear adhesion than those treated only with plasma nitriding, but the total wear volume is reduced. In this paper, the fretting wear of high strength steel alloy with different surface treatments is simulated by the finite element method. The coefficient of friction and wear volume can be obtained from the experimental results, and the wear coefficient is calculated using the wear energy model. The predicted two-dimensional wear profile curves (U-shape and W-shape wear profiles) under different wear conditions are compared with the experimental results. The W-shape wear profile is used to describe the adhesion state of the worn surface. In addition, the surface deformation and mechanical properties of U-shape and W-shape wear profiles are analysed. The simulation results show that double-sided wear and the addition of adhesive layer is important for the prediction of wear characteristics.

Energy absorption in expanding metallic wire mesh tubes

The deformation process and energy absorption of metal wire mesh tubes under quasi-static expanding by a hemispherical-cylindrical indenter were investigated by experimental tests, finite element (FE) simulations and analytical modelling. Stainless steel and aluminum alloy tubes were tested on an MTS universal testing machine at a speed of 10 mm/min. The effects of mesh cell size and friction coefficient on the quasi-static force and specific energy absorption (SEA) were examined by FE analysis and analytical modelling. The analysis reveals that a combination of the mesh cell size and cross section dimension of the wire governs the energy absorption of tubes of equal overall dimension (diameter and length) and masses. In general, a decrease of the size of cells with constant height-to-width ratios leads to an increase of the specific energy absorption mainly due to the increased number of cells within the deformed region. An increase of the specific energy absorption is also achieved when the cell size is reduced by only decreasing the cell height. The maximum indenter force predicted by the proposed analytical model of the expanded tube deformation agrees well with the experimental results and FE simulations.

Synthesis and Corrosion Performance Evaluation of Nanostructured Duplex Stainless Steel Alloys Prepared by MA and SPS

Synthesis and Corrosion Performance Evaluation of Nanostructured Duplex Stainless Steel Alloys Prepared by MA and SPS

Fatigue behaviour and life prediction of self-piercing riveted joints in DP590/AA5754 dissimilar sheets

This paper investigates the fatigue properties of self-piercing riveted joints made by DP590 steel and AA5754 aluminium alloy. The fatigue failure mechanism and fatigue fretting mechanism of the joint were well revealed by analysing the microstructure features of fracture surfaces of sheets and rivets as well as viewing and measuring the distribution and chemical composition of fretting debris. The fatigue life of the joint was also predicted based on the stress intensity factor of the kinked crack of the lower sheet. The results confirmed that two failure modes occurred during fatigue: lower sheet fracture and rivet fracture. During the fatigue failure, cracks appeared in both the lower sheet and the rivets, indicating a competitive relationship between the propagation of cracks in the lower sheet and the rivets. In the range of 40 % and 50 % load level, fatigue crack propagation of the lower sheet is dominant and fracture failure of the lower sheet occurs. Rivet fatigue crack propagation has a significant advantage in the 60 % load range and rivet fracture failure often occurs. It was found that the fatigue failure of the lower sheet is mainly influenced by the main crack, which produces two different morphological sections. Fretting wear of the contact surface was the source of crack initiation, and the fretting debris promoted crack initiation and propagation. Cracks propagate along the width and thickness of the plate, as well as the thickness of the rivet neck. The stress intensity factor range can properly predict the fatigue life of joints.

Influence of Laser Texturing and Coating on the Tribological Properties of the Tool Steels Properties

The article is aimed at identifying the influence of laser texturing and subsequent coating with a hard, wear-resistant coating AlCrSiN (nACRo®) on selected tribological properties of the analyzed tool steels for cold work, produced by conventional and powder metallurgy. The substrate from each steel was heat treated to achieve optimal properties regarding the chemical composition and the method of production of the material. Böhler K100 and K390 Microclean® steels were used. These are highly alloyed tool steels used for various types of tools intended for cold work. The obtained results show that the coefficient of friction is increased by coating, but the wear rate is lower compared to the samples which were only textured.

Characterization of hydrogen embrittlement sensitivity of 18CrNiMo7-6 alloy steel surface-modified layer based on scratch method

PurposeThe purpose of this paper is to assess the hydrogen embrittlement sensitivity of carbon gradient heterostructure materials and to verify the reliability of the scratch method.Design/methodology/approachThe surface-modified layer of 18CrNiMo7-6 alloy steel was delaminated to study its hydrogen embrittlement characteristics via hydrogen permeation, electrochemical hydrogen charging and scratch experiments.FindingsThe results showed that the diffusion coefficients of hydrogen in the surface and matrix layers are 3.28 × 10−7 and 16.67 × 10−7 cm2/s, respectively. The diffusible-hydrogen concentration of the material increases with increasing hydrogen-charging current density. For a given hydrogen-charging current density, the diffusible-hydrogen concentration gradually decreases with increasing depth in the surface-modified layer. Fracture toughness decreases with increasing diffusible-hydrogen concentration, so the susceptibility to hydrogen embrittlement decreases with increasing depth in the surface-modified layer.Originality/valueThe reliability of the scratch method in evaluating the fracture toughness of the surface-modified layer material is verified. An empirical formula is given for fracture toughness as a function of diffused-hydrogen concentration.

Microstructures and properties of 7075 aluminum alloy and CP780 steel resistance spot welded joint assisted by magnetic field

Joining steel and aluminum is vital for lightweight automobile but still challenging due to their different physical properties. Herein, resistance spot welding tests were performed on CP780 high-strength steel (thickness 1 mm) and 7075 aluminum alloy (thickness 1.5 mm) dissimilar metals under steady-state magnetic field. The influences of magnetic field (B = 40 mT) on the structure of welded joints, the phase composition/content of intermetallic compounds, and tensile properties of welded joints were analyzed under different welding current conditions (I = 9 kA,10 kA, 11 kA, and 12 kA). At the same welding current, the Lorentz force generated by the additional magnetic field promoted the outward circumferential movement of the molten metal in the weld along the horizontal surface , as well as increased the diameter of the Fe/Al contact interface in the weld nugget along the horizontal direction, conducive to the effective utilization of heat of the resistance spot welding. Except under (11 kA-0 mT) and (11 kA-40 mT), welded joints under other welding parameters displayed a few welding defects, such as incomplete fusion and shrinkage cavity formed at the cross-section of the welded joints. Therefore, the synergism between the magnetic field and appropriate welding current held important roles in the formation of welded joints without obvious welding defects. The intermetallic compounds of all the welds were mainly composed of (Fe, Si)Al2 and (Fe, Si)Al5. Meanwhile, the thickness and content of the intermetallic compounds layer reduced under a magnetic field at the same welding current, significantly improving the tensile properties of the welded joints. The comprehensive properties of welded joints were the best under 11 kA-40 mT, with an average shear force increase from 3.02 kN to 3.49 kN (15.56%) and an average displacement increase from 1.01 mm to 1.22 mm (20.79%). Overall, the proposed dissimilar aluminum/steel resistance spot welded joint assisted by magnetic field looks promising for lightweight automobile use.

Influence of cashew nut shell liquid on corrosion and tribocorrosion behavior of metallic alloys

Cashew Nut Shell Liquid (CNSL) has been explored in several applications within the sustainability principles and circular economy of agro-industrial product waste. To understand the anticorrosive and lubricant properties of CNSL solutions, a multi-faceted approach, incorporating electrochemical analyses, immersion test, tribological measurements, and tribochemical characterization was carried out for mild steel AISI 1012, stainless steel AISI 420 and Aluminium Alloy 6061. Electrochemical analyses reveal a positive impact of CNSL, inducing a shift in corrosion potential to more positive values and a decrease in corrosion current, indicating effective corrosion inhibition for stainless steel and aluminium alloy. In mild steel, CNSL exhibits a mixed-type inhibition with efficiency increasing in correlation with oil concentration. The lubricating properties of CNSL are evident according to the coefficients of friction (COF) obtained and the elastohydrodynamic lubrication regime observed during tribological tests. Tribochemical tests demonstrate a reduction in wear and an improvement in tribocorrosion behavior under sliding conditions. CNSL emerges as a promising tribocorrosion mitigator, demonstrating multifaceted benefits. The concentration-dependent effects highlight the need for optimization in specific applications, particularly for passive materials. CNSL not only inhibits corrosion through film formation but also provides effective lubrication, reducing friction, wear, and chemical-mechanical degradation. This research contributes valuable insights to corrosion science. It proposes practical applications for CNSL in diverse industrial contexts, showcasing its potential as an environmentally friendly and sustainable solution for tribocorrosion challenges.