Surface Roughness Of Steel Research Articles

Electric-Spark Alloying of Metal Surfaces with Graphite

The article reviews and analyses the current scientific research in the field of surface treatment of metal surfaces with concentrated energy fluxes (CEF) — the electric-spark (in the literature, known also as electrospark) alloying (ESA), which makes it possible to obtain surface structures with unique physical, mechanical and tribological properties at the nanoscale. The ESA method with a graphite electrode (electrospark carburizing — EC) is based on the process of diffusion (saturation of the surface layer of a part with carbon), and it is not accompanied by an increase in the size of the part. In this article, the influence of the EC parameters on the quality of the carburized layer is investigated. The microstructural analysis shows that the three characteristic zones could be distinguished in the structure: the carburized (‘white’) layer, the finely dispersed transition zone with fine grain, and the base metal zone. The analysis of the results of the durometric studies of the coatings is carried out. To achieve the required parameters of dimensional accuracy and roughness of the working surface of the part after the EC process, it is necessary to use the method of non-abrasive ultrasonic finishing (NAUF). In addition, because of applying the NAUF method, the surface roughness is decreased, the tensile stresses are changed to the compressive ones, and the fatigue strength is increased too. In addition, to reduce the roughness of the treated surface, it is proposed to apply the EC technology in stages, reducing the energy of the spark discharge at each subsequent stage. In order to increase the quality of the carburized layer obtained by the EC process, it is proposed to use a graphite powder, which is applied to the treated surface before alloying. The comparative analysis shows that, after the traditional EC process at Wp = 4.6 J, the surface roughness of steel 20 is Ra = 8.3–9.0 μm, and after the proposed technology, Ra = 3.2–4.8 μm. In this case, the continuity of the alloyed layer increases up to 100%; there increases the depth of the diffusion zone of carbon up to 80 μm as well as the microhardness of the ‘white’ layer and its thickness, which increase up to 9932 MPa and up to 230 μm, respectively. The local micro-x-ray spectral analysis of the obtained coatings shows that, at the EC process carried out in a traditional way, the applying Wp = 0.9, 2.6, 4.6 J provides the formation of the surface layers with high-carbon content depths of 70, 100, 120 μm, respectively, and with the use of a graphite powder, they are of 80, 120, 170 μm. While deepening, the amount of carbon is decreasing from 0.72–0.86% to the carbon content in the base metal — 0.17–0.24%. In the near-surface layer formed with the use of the new technology, the pores are filled with free graphite, which could be used as a solid lubricant to improve the operating characteristics of the friction-pairs parts processed thereby.

Investigation of Hadfield Steel Machinability in Milling Operations

Hadfield steel is widely used in the manufacture of machines and mechanisms operating in harsh conditions. When machining Hadfield steel parts, problems are due to the strain hardening. The article studies the influence of cutting modes on steel hardness, tool thrust and surface roughness when milling Hadfield steel using cutters with replaceable inserts. The experiments were conducted on a milling machining center using high-productivity cutting tools. The optical roughness measuring method was applied. Hardness was measured with a portable hardness tester before and after milling. The article describes experimental results that show the dependence of the output machining parameters on the cutting speed and feed per tooth. The influence of cutting data on tool life in a finish milling operation was identified. The results will help to improve the quality and productivity and increase the tool life in roughing and finishing Hadfield steel parts.

Effect of Machining Parameters on Surface Roughness and Metal Removal Rate for AISI 310 L Stainless Steel in WEDM

Wire electrical discharge machining (WEDM) is a non-traditional machining process that is widely used in the machining of conductive materials. This paper presents the investigation on surface roughness and metal removal rate of stainless steel using the wire-cut EDM process. Process input parameters wire feed (WF), wire tension (WT), servo voltage (SV), pulse on time (TON) and pulse off time (Tuff), and the output parameters surface roughness and metal removal rate. The work piece material was used stainless steel 310 L, zinc-coated brass wire of 0.25mm diameter used as a tool and distilled water is used as dielectric fluid. ANOVA used to measure and evaluate the relative importance of different factors. Experiments are designed and analyzed using the factorial design approach. The experimental results revealed that the most important machining parameter of the pulse of time has the most influence on the metal removal rate and the surface roughness. The maximum best metal removal rate is (0.052277 g/min). When the values are somewhat medium range, they are the best and the wire does not break at this range. Wire feed (7m/min), wire tension (7 kef), servo voltage (30 V), TON (30 sic), Tuff (30 sic). The expected values and measured values are well-matched as observed by additional confirmation experiments.

Numerical and Experimental Analysis of Surface Roughness of AISI D3 Alloy Steel during Pocket Milling Operation

Numerical and Experimental Analysis of Surface Roughness of AISI D3 Alloy Steel during Pocket Milling Operation

Machinability study and optimization of tool life and surface roughness of ferrite: Bainite dual phase steel

Aim of this present research work is to obtain the machining parameters to optimize the tool life and surface roughness for ferrite-bainite dual phase steel. Machinability tests are carried out using orthogonal array of 27, the Taguchi method, in which the machining parameters are considered as control factors. The effect of speed, feed and depth of cut on tool life and surface roughness of dual phase structure steel is analysed using ANOVA. Regression analysis is used to obtain the equations for predicting the tool life and surface roughness. Experiment is conducted using uncoated carbide insert tool by varying the process parameters. Optimum tool life and surface is analysed using Response Surface Methodology. Hardness and microstructure revealed the dual phase condition in different intercritical zones. It is found that hardness improves as the intercritical temperature is increased from 750 to 770°C. Experimental results prove that dual phase structure has better machining characteristics at an intercritical temperature of 750°C.

Effect of process parameters on surface roughness of 316L stainless steel coated 3D printed PLA parts

3D printing is a novel and rapid emerging technology. Among distinct 3D printing techniques, Fusion deposition modeling (FDM) is one of the cost effective 3D printing technique. In addition, in FDM process, polylactic acid (PLA) filaments are generally utilized. However, the quality of FDM fabricated part depends upon many processing parameters. Hence, in the current investigation PLA samples have been fabricated using FDM at distinct parameters. Further, the fabricated samples were coated at different levels (50 µm, 100 µm and 150 µm) with 316L stainless steel using electric arc spray. Finally, the surface roughness of the fabricated samples was measured. The result showed that the, surface roughness is higher (14.9 µm) at raster orientation (30°), top and bottom layer (2), and coating thickness (50 µm). On the other hand the surface roughness was found to be lower at raster orientation (60°), top and bottom layer (4), and coating thickness (150 µm).

Evaluation of Surface Grinding Response Parameters of EN31 Alloy Steel

The purpose of this study is to understand the influence of processing parameters on surface roughness and material removal rate of EN31 Alloy Steel. Three input parameters are considered in this study, namely, the speed of the grinding wheel, number of passes and the depth of cut. The L16 orthogonal array design is used to analyse these process parameters. The results show that cutting depth and grinding wheel speed are the most effective parameters affecting material removal rate and cutting depth, and the number of passes is the most effective parameter affecting surface roughness. In addition, result showed that, the maximum MRR is 0.79051 g/sec and the surface roughness is 0.14000 µm. Therefore, it can be concluded that compared with other materials, cutting depth and wheel speed are less effective parameters, but compared with EN31 alloy steel, cutting depth and grinding wheel speed are the most effective parameters.

Experimental investigation of process parameters on surface roughness and dimensional accuracy in hard turning of EN24 steel

Hard turning is the process of cutting hardened components with hardness ranging from 45 to 70 HRC within the 2-µm range. Hard turning differs from traditional turning in the sense that during hard turning it is very difficult to achieve surface finish and dimensional accuracy as compared to traditional turning. The present work focuses on the investigation of surface roughness and dimensional accuracy of EN24 steel in hard turning. Cutting tool used in this experimentation is CBN. Speed of spindle, rate of feed, nose radius, and cut depth are all variables in the process. The process is carried out by CNC lathe machine. Surface roughness values are measured by surface roughness meter and dimensional accuracy is measured using precision dial gauge. Taguchi method is used to conduct a set of experiments using design of experiments (DOE) with L9 orthogonal array. Using a statistical technique, the best values for process parameters such as surface roughness and dimension accuracy are determined based on experimental findings. The ideal process parameters on response, such as surface roughness and dimensional accuracy, were determined using analysis of variance (ANOVA). The Signal to Noise (S/N) Ratio was utilised to determine the ideal process parameter levels. The results show that spindle speed has the greatest impact on component surface roughness, followed by insert nose radius, while feed rate and cutting depth have a lesser impact when compared to the other factors. Furthermore cutting depth has significant influence on Dimensional accuracy of parts followed by spindle speed and nose radius, where as feed rate has little influence compared to others parameters.

КРАТНОМАСШТАБНЫЙ ВЕЙВЛЕТ-АНАЛИЗ ПРОФИЛОГРАММЫ

The functional properties of the surface are significantly affected by its microgeometry, therefore it is necessary to optimize the parameters of the microgeometry of the surface of metal structures. The analysis and evaluation of the microgeometry of the surface allows an assessment of the fatigue strength of metal structures. In order to study the dependence of the durability of thin-sheet structures on the degree of corrosion destruction, the microgeometry of the surface was analyzed using a profilometer 130 in accordance with GOST 25142-82. Low-carbon cold-rolled steel 08kp was used as the test material. The surface roughness of the samples was Ra = 0.22 microns. The roughness parameters were calculated according to GOST 2789-73. A profilogram representing a discrete series of values of peaks and troughs of the relief of the metal plate surface was studied. To assess the microgeometry of the surface, a wavelet analysis was used, which allows processing signals that are nonstationary in time or inhomogeneous in space. The signal in the form of successive approximations has a trend, cyclic components and local features (fluctuations) around the components of the signal. The locality property of wavelets gives advantages over the trigonometric Fourier transform: the sines and cosines are defined on the entire numerical axis, and the wavelets have a compact carrier. For multiscale analysis, a fast cascade algorithm of calculations has been developed by analogy with the fast Fourier transform. In the study, the signal was decomposed to the 9th level. The reconstructed detailing coefficients represent high-frequency and low-frequency fluctuations. The decomposition of the signal to the 9th level made it possible to analyze the surface roughness of the 08kp steel using a multiple-scale wavelet analysis.

A novel optimization of feed and spindle speed levels for surface roughness and cylindricity tolerance while drilling normalized and annealed EN8 steel with tungsten carbide and comparing the outputs with untreated EN8 steel

The main aim of this research is to compare the cylindricity tolerance and roughness of holes made in normalized and annealed EN8 steel with that of untreated EN8 steel. EN8 steel plate with a thickness of 10 mm was used in this research work. EN8 steel was normalized at 750 °C and annealed at 840 °C with the aid of a muffle furnace. Then drilling was carried out with tungsten carbide drills. Cylindricity tolerance tests and surface roughness tests were carried out as per the ASTM standards. Each plate of the experimental group (annealed and normalized EN8 steel) and control group (untreated EN8 steel) contains 39 test samples (N = 39). G power 80% was used to calculate sample size. Untreated EN8 steel appears to have more cylindricity tolerance and roughness (0.0601 µm, 3.95 µm) than Normalized EN8 steel (0.0533 µm, 3.28 µm) and annealed (0.0489 µm, 3.08 µm) EN8 steel. According to statistical analysis it appears that significance is p = 0.000 and p < 0.05. Within the limitations of this study, it has been found that heat treatment of EN8 steel improved the surface roughness and tolerance, particularly annealing yielded a significant increase in the surface roughness and tolerance of EN8 steel.

Effect of Machining Parameters on Tool Life and Surface Roughness of AISI 1040 Dual Phase Steel

The purpose of this research is to investigate the effect of heat treatment parameters on the tool life and surface roughness of dual phase steel. Optimization of machining parameters (cutting speed, feed and depth of cut) is carried out for the machinability tests on medium carbon low alloy steel. Taguchi’s method of design is used to carry out machinability tests. Analysis of variance (ANOVA) is carried out to determine the relative contribution of machining parameters on tool life and surface roughness. Microstructure analysis is carried out to ascertain the machining behavior of the steel. Results have shown that, depth of cut and cutting speed are the most significant factors contributing on the variation of the tool life and surface roughness. Optimized machining parameters are calculated in order to obtain higher tool life and lower surface roughness value.

Optimization of Process Parameter in Wire Electrical Discharge Machining of H11 Tool Steel Using Response Surface Methodology

Abstract: Conventional machining is now being superseded by non-conventional machining to cope up with increased demand of machining of complex shapes with high surface finish machining and dimensional accuracy. Wire electric discharge machining (WEDM) is electro-thermal principle based nontraditional machining, widely used for machining of electrically conductive materials. This paper summarized, the parametric influence of Pulse-on duration (Ton), Pulse-off duration (Toff) and Pulse peak current (Ip) on material removal rate (MRR), surface roughness (SR) of H11 tool steel. Response surface methodology (RSM) is used for modelling and optimization. ANOVA has been carried out to identify importance of the machining parameters on the performance characteristics considered. Further the verification experiment has been carried out to confirm the performance of optimum parameters. The results from this study will be useful for selecting appropriate set of process parameters to WEDM machining of H11 tool steel.

Structural variations on the surface of metallic products at laser marking

Laser marking of products and details is used more and more wide in different production areas, because it has undisputable advantages in comparison with other marking methods. Action of laser beam on the surface of marking product is the principal feature of laser marking. It is accompanied with local heating of this surface and its partial melting together with material evaporation from the surface contact point. Influence of laser impulse action on efficiency of marking on the surface of machine-building details is examined in this work. The samples of 08Kh18N10 steel were used as material. Marking was conducted by the system &ldquo;MiniMarker 2-20A4&rdquo;, QR code was used as a marker. The marking parameters were optimized via the method of experimental design. The optimal marking procedure for getting maximal contrast of QR code was calculated and experimentally confirmed. Steel surface roughness was analyzed using profilograms. Contrasting effect and roughness of code were determined and relationship between these parameters was revealed. Contrast effect of marking increases with elevation of roughness. However, roughness has less input in increase of contrast effect comparing with colour hue of the surface of an information block and substrate. The link between surface roughness and contrast effect of marking is shown. Possibility of contrast effect assessment of QR code using profilometer is suggested. The reported study was financially supported by the&nbsp;Ministry of Science and Higher Education of the Russian&nbsp;Federation, research agreement No. 075-11-2019-066 of&nbsp;22.11.2019, project title &ldquo;Development of high-tech production&nbsp;of equipment and technologies for laser coding of&nbsp;transported goods and their optical identification for the&nbsp;implementation in modern material flow management systems&rdquo;&nbsp;(within the framework of decree of the Government&nbsp;of the Russian Federation, No. 218 of 09.04.2010).

Impact of soot nanoparticle size and quantity on four-ball steel wear characteristics using EDS, XRD and electron microscopy image analysis

The effect of soot contamination on the tribological performance of engine oil was investigated. Carbon black is introduced to simplify diesel engine soot contamination. Besides, the tribological performance issue is verified by a four-ball tribometer. The steel ball worn surfaces were studied by Scanning Electron Microscopy (SEM), Optical Microscope (OM) and Energy Dispersive X-ray spectroscopy (EDX). In addition, Transmission Electron Microscopy (TEM) was used to investigate the morphology and nanostructure of soot and carbon black. According to the four ball test results, the average wear scar diameter of steel ball tested with engine oil blended with N220, N330, N550 and N660 by 1% by weight is larger than that of pure engine oil by 26%, 38%, 41%, and 39%, respectively. The wear scar diameter tends to increase after blended larger size of carbon black particle. The steel balls tested with formulated engine oil without soot contamination and with soot contamination by 0.5 wt%, 1 wt%, and 2 wt% have average wear scar diameters of 621, 567, 784 and 894 nm, respectively. On the other hand, wear scar roughness of steel balls tested with formulated engine oil without soot contamination and with soot contamination by 0.5 wt%, 1 wt%, and 2 wt% were 2.28, 0.25, 1.49 and 1.76 μm, respectively.Consequently, quantity of the soot nanoparticle approximately 0.5% by mass in engine oil significantly plays an important role in steel ball wear scar diameter and surface roughness reduction. Moreover, the agglomerated soot which is larger than the oil film thickness might block the lubricant from entering the contact. It leads to the breakdown of the oil film thickness resulting in increasing adhesive wear on the worn surface.

Microfluidic water flow on laser-patterned MicroCoat® - coated steel surface

A series of hybrid textures with variable topography and chemical composition were obtained on a hydrophilic steel (AISI 304) substrate with a hydrophobic MicroCoat® coating at the increasing incident nanosecond laser fluence from 1.4 J/cm2 to 5.6 J/cm2. The microtopography of the textured surface was studied by laser microscopy and scanning electron microscopy (SEM), while the chemical composition of the surface was determined by IR spectroscopy. The contact angles of water wetting in the textured areas varied versus laser fluence from about 100° to 10°, which was explained by both ablative removal of the hydrophobic polymer coating and the increase in roughness of the hydrophilic steel surface. The time dependence of the contact angle on the different textures, which demonstrated hydrophobization at different time scales depending on the texturing conditions, was analyzed. Autonomous directional flow was observed on laser-patterned wetting-gradient structures of various shapes, and the flow velocity of water droplets on these structures were measured. It was shown that the velocity of water drop spreading on the gradient structures depends on the difference in contact angles on adjacent spots. The various modules fabricated can be harnessed in chemical and biomedical microfluidic devices.

Investigation and Mathematical Modelling of Optimized Cutting Parameters for Surface Roughness of EN-8 Alloy Steel

The work done in this work deals with the efficacy of cutting parameters on surface of EN-8 alloy steel. For knowing the optimal effects of cutting parameters response surface methodology was practiced subjected to central composite design matrix. The motive was to introduce an interaction among input parameters, i.e., cutting speed, feed and depth of cut and output parameter, surface roughness. For this, second order response surface model was modeled. The foreseen values obtained were found to be fairly close to observed values, showed that the model could be practiced to forecast the surface roughness on EN-8 within the range of parameter studied. Contours and 3-D plots are generated to forecast the value of surface roughness. It was revealed that surface roughness decreases with increases in cutting speed and it increases with feed. However, there were found negligible or almost no implication of depth of cut on surface roughness whereas feed rate affected the surface roughness most. For lower surface roughness, the optimum values of each one were also evaluated.

Fatigue behaviour of non-welded wrapped composite joints for steel hollow sections in axial load experiments

Design and execution of fatigue load dominated circular hollow section (CHS) multi-membered structures, such as offshore jacket and floating structures for wind turbines, truss bridges, etc., is hinged on fatigue performance of critical welded joints. An innovative jointing technology of wrapped composite joint connects steel hollow sections by direct bonding through a fibre reinforced polymer composite wrap, which completely avoids welding and therefore has superior fatigue performance than welded joints. In this study first results on fatigue performance of the wrapped composite joints is presented. Tensile cyclic loading tests on wrapped composite X-joint specimens were carried out to characterise their fatigue performance under different constant amplitude load ranges and compare it to equivalent welded joints. In addition, the influence of surface roughness of steel tubes and re-testing (load history) on fatigue performance of wrapped composite joints, as well as the influence of fatigue loading on residual static resistance was investigated in experiments. Preliminary S-N curves of wrapped composite joints are established. The tests results showed that X45 wrapped composite joints exhibited steadier stiffness degradation and 10–100 times longer fatigue life than their welded equivalents. Through 3D DIC surface strain measurements and post-failure microscopic insights to cut specimens, different failure modes including de-bonding at glass fibre composite-to-steel interface, delamination/fracture of the composite layers and fracture of steel brace are distinguished. The relationship between joint stiffness degradation rates, crack propagation rates and nominal stress ranges in the brace are established, based on which a preliminary fatigue life prediction of wrapped composite joints can be made. The re-tested specimens exhibited superior fatigue performance than virgin ones, while specimens with poor steel surface roughness showed worse fatigue performance. After fatigue loading with 40% of stiffness degradation, the specimens were found to still have the potential to sustain its original static resistance.

Parameter optimization of AISI 316 austenitic stainless steel for surface roughness by Grasshopper optimization algorithm

This article describes the optimization of processing parameters for the surface roughness of AISI316 austenitic stainless steel. While experimenting, parameters in the process like feed rate (fd), speed (vc), and depth of cut (DoC) were used to study the outcome on the surface roughness (Ra) of the workpiece. The experiment was carried out using the design of experiments (DOE) on a computer numerical control (CNC) lathe. The surface roughness is tested for three conditions i.e. Dry, Wet, and cryogenic conditions after the turning process. Samples are step turned on CNC Lathe for all three conditions with a set of experiments designed. The response surface methodology is implemented, and mathematical models are built for all three conditions. The nature-inspired algorithm is the best way to get the optimal value. For the discussed problem in the paper, nature-inspired techniques are used for obtaining the optimum parameter values to get minimum surface roughness for all set conditions. The Grasshopper optimization algorithm (GOA) is the technique that is the most effective method for real-life applications. In this research, GOA is used to get optimum values for the surface roughness (Ra) at Dry, Wet and cryogenic conditions. Finally, results are compared, and it's observed that the values obtained from GOA are minimum in surface roughness value.

Study on Deterioration Characteristics of Low-Carbon Steel’s Mechanical Properties and Fracture Mechanism under Marine Engineering Environment

In order to study the mechanical properties of low-carbon steel under the coupling effect of the overall environment and the loads, the tensile mechanical test was carried out. The results indicated that, as the sea water concentration and tensile deterioration increased, both the mass-loss rate and surface roughness of the low-carbon steel gradually increased, and the yield strength, tensile strength, elongation, and section shrinkage decreased gradually. The mechanical parameters of the low-carbon steel were affected by the joint actions of the sea water concentration and tensile deterioration. The established mechanical model of low-carbon steel under the marine engineering environment shows that tensile deterioration had no effects on the fracture toughness, while the increase of sea water concentration could reduce the fracture toughness remarkably.

The effect of post-processing operations on mechanical characteristics of 304L stainless steel fabricated using laser additive manufacturing

Metal additive manufacturing (AM) is an innovative method for fabricating products used in aerospace, automobile, and medical industries. Research on AM has been extensively conducted because AM can be applied to fabricate features and shapes difficult or impossible to produce using conventional machining (CM) method. However, a problem with this method is the low surface quality of the fabricated product, which necessitates post-processing after the AM process. In this study, CM and induction-assisted machining (IAM) were performed to improve the cutting force, surface roughness, hardness, and microstructure of 304L stainless steel fabricated through AM. First, a 304L stainless steel workpiece was fabricated through AM using metal powder and direct energy deposition. Before the IAM, a thermal analysis was performed to determine the effective depth of cut. After post-processing, the cutting force and surface roughness were measured to investigate the machining characteristics. It was confirmed that the hardness increased because of work hardening, thermal treatment effect and grain growth after CM and IAM. Therefore, CM and IAM can be used for post-processing to improve the machinability, hardness, and microstructure of the fabricated AM product.