Surface Roughness Of Steel Research Articles

The effect of 316 steel surface roughness on absorption of 1064 nm laser emissions

The effect of 316 steel surface roughness on absorption of 1064 nm laser emissions

Study on the effects of laser shock peening on the microstructure and properties of 17-7PH stainless steel

To investigate the surface integrity of 17-7PH stainless steel welded structural components used in aviation, laser shock peening (LSP) with different power densities was applied to stainless steel welded joints. The microstructural morphology, structural features, full-width at half-maximum, microhardness, and surface roughness of the stainless steel welded joint specimens before and after LSP were characterized and measured using SEM, TEM, XRD, a microhardness tester, and a high-resolution confocal microscope. The effects of different laser power densities on the microstructure and properties of the stainless steel welded joints were explored. Results indicate that the stainless steel welded joints exhibit a typical BCC phase. Laser shock peening promotes grain refinement in the welded joints, leading to the phase transformation of residual austenite into martensite. The surface roughness of the specimen is positively correlated with laser power density. At a power density of 5.17 GW/cm2, the surface roughness increased to 1.919 μm, which is 117.08% higher than that of the non-peened specimen. The microhardness of the specimens shows a decreasing trend with increasing power density. When the power density is 2.79 GW/cm2, the microhardness of the specimen significantly increases to 462.94 HV0.5, which is 22.26% higher than that of the non-peened specimen.

Numerical prediction on the fatigue debonding behaviour in a complex bi-material interface: A case study on wrapped composite joints

Debonding is one of the most critical failure modes for bonded joints under fatigue loads. Numerical prediction on the fatigue debonding behaviour of bonded interfaces with complex geometry still remains a problem. This paper proposes a numerical methodology based on fracture mechanics to predict crack growth in a complex bi-material interface and illustrates the prediction procedure by a case study on wrapped composite joints. Interface coupon tests provide the fatigue crack growth properties at the composite-to-steel interface used as inputs for finite element (FE) modelling. The FE model is calibrated against fatigue tests of small scale wrapped composite joints with different steel surface roughness subject to different load levels. A sensitivity analysis is conducted to investigate the influence of key modelling parameters. The calibrated model is validated against fatigue tests on upscaled joints. Good agreements are shown between the test and modelling results in terms of crack growth and stiffness degradation, demonstrating the potential of the proposed numerical methodology for predicting fatigue debonding behaviour of complex bi-material interfaces.

Qualitative surface roughness of lithium disilicate endo-crown for pulpotomized primary molars

Rehabilitation of pulpotomized primary molars with an appropriate restoration is essential for recovering function and safeguarding the durability of the treatment. This study aimed to assess and compare the surface roughness of stainless steel (ST) crowns, zirconia (ZR) crowns, fiberglass (FG) crowns, and lithium disilicate (LD) endo-crowns as a restoration for pulpotomized primary molars also, evaluating the surface roughness of their antagonists. Sixty pulpotomized primary mandibular first molars were used for qualitative surface roughness evaluation and divided into four groups (n = 15/group) according to the crown type (group-ST, group-ZR, group-FG, group-LD). While the other sixty sound, unprepared primary maxillary first molars were used for evaluation of their surface roughness against the tested crowns. Specimens’ preparation and cementation were carried out according to each crown type and manufacturer’s instructions. The surface roughness was done using a two-body wear test. The data were statistically analyzed. All tested crowns showed an increased change in surface roughness, except group-ZR, which had the least change in surface roughness after mechanical wear with no statistically significant difference(P = 0.681). All crown types significantly increased the surface roughness of their antagonists after mechanical wear, except group-ST which showed insignificant affection (p ≥ 0.05). Zirconia crowns and lithium disilicate endo-crowns had the least change in surface roughness compared to other groups while SSCs showed the least tooth loss in the antagonist enamel.

INFLUENCE OF PROCESS PARAMETERS ON ANODIC PLASMA ELECTROLYTIC POLISHING OF Q235 LOW-CARBON STEEL IN (NH4)2SO4 ELECTROLYTE

The plasma electrolytic polishing (PEP) process on Q235 low-carbon steel anode in [Formula: see text]SO4 electrolyte was investigated, and its surface properties under different PEP conditions were evaluated. The surface roughness of PEP samples under different electrolyte concentrations, initial roughness, voltages and treating times were measured. The surface morphologies and compositions of typical PEP samples were analyzed, and their wettability and surface free energy under different polishing times were evaluated. It was found that the near-surface temperature of the steel sample raised quickly with increasing the voltage, and then remained at about 100°C after 200[Formula: see text]V, which is beneficial to keep the microstructure and mechanical properties of Q235 low-carbon steel. Under the parameters of 3.0[Formula: see text]wt.% [Formula: see text]SO4 aqueous solution and applied voltage of 200[Formula: see text]V, the 8[Formula: see text]min PEP treatment could reduce the surface roughness of Q235 low-carbon steel from 2.100[Formula: see text][Formula: see text]m to 0.437[Formula: see text][Formula: see text]m. In addition, the polishing efficiency was the highest in the initial PEP stage, meanwhile, it also increased with the increase of initial roughness of the sample. After the PEP treatment, the contact angle of water on low-carbon steel decreased, and its surface free energy was slightly reduced. Moreover, the thickness of natural oxide film on Q235 low-carbon steel was reduced by about 30% after 8 min polishing treatment.

Gemini cationic surfactant of 1, 3-bis (dodecyl dimethyl ammonium chloride) propane as a novel excellent inhibitor for the corrosion of cold rolled steel in HCl solution

Gemini surfactants have become the research focus of novel excellent inhibitors because of their special structure (two amphiphilic moieties covalently connected at head group by a spacer) and excellent surface properties. It is proved by theoretical calculations that 1, 3-bis (dodecyl dimethyl ammonium chloride) propane (BDDACP) molecules can perform electron transfer with Fe (110). And it has a small fraction free volume, thus greatly reducing the diffusion and migration degree of corrosive particles. The potentiodynamic polarization curve showed that coefficients of cathodic and anodic reaction less than 1 and polarization resistance increased to 1602.9 Ω cm−2 after added BDDACP, confirming that BDDACP significantly inhibited the corrosion reaction by occupying the active site. The electrochemical impedance spectrum of imperfect semi-circle shows that the system resistance increases and double layer capacitance after added BDDACP. Weight loss tests also confirmed that BDDACP forms protective film by occupying the active sites on steel surface, and the maximum inhibition efficiency is 92 %. Comparison of the microscopic morphology showed that steel surface roughness was significantly reduced after added BDDACP. The results of time-of-flight secondary ion mass spectrometry show that steel surface contains some elements from BDDACP, which confirms the adsorption of BDDACP on steel surface.

Melt Pool characteristics on surface roughness and printability of 316L stainless steel in laser powder bed fusion

Purpose Surface quality and porosity significantly influence the structural and functional properties of the final product. This study aims to establish and explain the underlying relationships among processing parameters, top surface roughness and porosity level in additively manufactured 316L stainless steel. Design/methodology/approach A systematic variation of printing process parameters was conducted to print cubic samples based on laser power, speed and their combinations of energy density. Melt pool morphologies and dimensions, surface roughness quantified by arithmetic mean height (Sa) and porosity levels were characterized via optical confocal microscopy. Findings The study reveals that the laser power required to achieve optimal top surface quality increases with the volumetric energy density (VED) levels. A smooth top surface (Sa < 15 µm) or a rough surface with humps at high VEDs (VED > 133.3 J/mm3) can serve as indicators for fully dense bulk samples, while rough top surfaces resulting from melt pool discontinuity correlate with high porosity levels. Under insufficient VED, melt pool discontinuity dominates the top surface. At high VEDs, surface quality improves with increased power as mitigation of melt pool discontinuity, followed by the deterioration with hump formation. Originality/value This study reveals and summarizes the formation mechanism of dominant features on top surface features and offers a potential method to predict the porosity by observing the top surface features with consideration of processing conditions.

An Experimental Study in Laser-Assisted Machining of AerMet100 Steel.

To solve the problems of poor surface quality and low tool life in conventional machining (CM) of AerMet100 steel, an experimental study was conducted in laser-assisted machining (LAM) of AerMet100 steel. The effects of laser power, cutting speed, feed rate, and depth of cut on the surface roughness of AerMet100 steel were studied based on a single-factor experiment. The degree of influence of each factor on the surface roughness was evaluated by analyses of variance and range in the orthogonal experiment, and the combination of process parameters for the optimal surface roughness was obtained. The order of influence was as follows: laser power > cutting speed > depth of cut > feed rate; the optimal combination of process parameters was laser power 200 W, cutting speed 56.5 m/min, feed rate 0.018 mm/rev, and depth of cut 0.3 mm. Compared to CM, the surface morphology of the workpiece under the optimization of LAM was relatively smooth and flat, the surface roughness Ra was 0.402 μm, which was reduced by 62.11%, the flank wear was reduced from 208.69 μm to 52.17 μm, there were no tipping or notches, and the tool life was significantly improved. The study shows that the LAM of AerMet100 steel has obvious advantages in improving surface quality and reducing tool wear.

Nucleation bubble boundary layer theory for ultra-fast electrochemical polishing of additive manufacturing components

The application of electrochemical-based polishing techniques, including electrochemical polishing (ECP) and plasma electrolytic polishing (PEP), to improve the surface quality of additive manufacturing (AM) components is challenged by the high amplitudes and long spatial wavelengths of roughness, which cause pre-polishing procedures to be indispensable. In this study, a nucleation bubble boundary layer (NBBL) mechanism for enhanced electrochemical-based polishing performance is revealed to solve this problem, namely nucleation bubble electrochemical polishing (NBEP). The NBBL is constructed on the anode surface via electrolytic oxygen evolution and nucleate boiling, and is activated by regulating the temperature and electric potential. The experiments verify a model of NBBL consisting of an inner adherent layer and outer diffusion layer (ODL). Simulations and experiments demonstrate that the polishing mechanism is based on the combined current-limiting effect of individual adherent bubbles and the ODL, which differentiates the anodic dissolution rates at the peaks and valleys of a wide range of spatial wavelengths with their electrical resistance. The bubble dynamics also enhance mass transfer, further improving the polishing efficiency. The experimental results show that NBEP is capable of reducing the surface roughness of AM stainless steel 316 L from Ra of 10.22 μm to 0.71 μm, and eliminating the spatial wavelengths of 200–400 μm in 8 min, which cannot be achieved by either ECP or PEP. The polishing current density also increased from 0.25 (ECP) and 0.48 (PEP) to 2 A/cm2 in NBEP. Finally, a prediction model that accurately describes the ultimate roughness achieved by NBEP as a function of the minimum cavity size is established. The NBEP can be directly followed by PEP or ECP to achieve an optimal surface finish of Ra <70 nm for AM parts. The NBEP method considerably enhances the polishing performance of electrochemical-based systems for AM components, as well as expands the application range of electrochemical-based polishing techniques.

Melt pool control-assisted additive manufacturing of thin-walled parts

Thin-walled aerospace components manufactured by laser directed energy deposition are susceptible to thermal accumulation effects owing to their deposition path and efficiency, further leading to the edge collapse. The melt pool width, as the carrier of thermal input, is an important geometric factor reflecting the state of the melt pool. Therefore, an in-situ melt pool control technique was proposed. The melt pool width as the control target was monitored using a coaxial camera, and the laser power was adjusted in real time based on the proportional-integral-derivative algorithm. A thermal accumulation model in conventional mode and a thermal suppression model in control mode were derived. The surface roughness, porosity, microstructure, and tensile properties of AISI 316 L stainless steel were compared between two modes. The results demonstrated that the roughness and porosity of thin-walled parts were respectively reduced by 45.3% and 82.7% after control. The periodic evolution of interlayer columnar and equiaxed crystals, and the increase in deformation twins contributed to a simultaneous increase in tensile strength and toughness, with a maximum increase of 35.7% in elongation.

Effect of corrosion on bond slipping between steel and concrete in SRC structures

Corrosion critically impacts bond performance in steel-reinforced concrete (SRC) structures. In this study, we investigate the impact of corrosion on bond-slipping between steel components and concrete within SRC structures. Initially, SRC specimens were subjected to electrochemical corrosion tests to induce varying corrosion rates. Then, pull-out tests were conducted to study the specimens' failure modes, bond stress–slip curves, and displacement distribution. The experimental results indicate that lower corrosion rates can increase bond strength due to enhanced steel surface roughness. As the corrosion rate increased from 0% to 5%, the initial bond stress, peak bond stress, and residual bond stress increased by 133%, 101%, and 102%, respectively. However, when the corrosion rate increased from 5% to 15%, these stresses decreased by 57.1%, 49.6%, and 49.6%, respectively. Furthermore, with an increase in corrosion rate from 15% to 20%, the initial, peak, and residual bond stresses decreased by 100%, 67.6%, and 69.0%, respectively. Corrosion considerably affected the initial and peak slipping observed between the steel components and the concrete, yet its impact on residual slip was relatively minor. In addition, a nonlinear finite element model for characterising the corrosion and pull-out tests was developed and validated according to the experimental results. The numerical results showed that the four shear transfer mechanisms, including chemical bonding, micromechanical interlocking, macromechanical interlocking, and rust interface bonding, exhibited distinct behaviours at different loading stages. Finally, a parametric study was conducted using a finite element model. With variations in corrosion rates, four modes of cracking patterns on the concrete surface were observed.

Machining characteristics and optimization of 10CrNi3Mo alloy steel by WEDM

ABSTRACT 10CrNi3Mo alloy steel has the characteristics of high hardness and wear resistance, and is widely used in aircraft and spacecraft, shipbuilding and so on. However, its conventional processing method has high tool loss. Wire Electrical Discharge Machining (WEDM) technology is based on electrode pulse discharge to corrode materials. There is no direct contact between the tool and the workpiece, so it is suitable for processing materials with complex shapes, such as high hardness and high brittleness. The focus of this study is to investigate the effects of different electrical parameters such as pulse width, pulse gap, current, and wire feeding speed on the recast layer thickness (RCL) and surface roughness (SR) of 10CrNi3Mo alloy steel processed by wire discharge machining using orthogonal experiments. The gray correlation method was used to optimize the above two process indicators, and seeking optimal processing parameters. The optimized recast layer thickness was 8.65 μ m. The surface roughness is 1.932 μ m. Achieve expected goals.

A study on Effect of Surface Finishing Processes on Surface Roughness of AISI D2 Tool Steel

According to recent studies, dry hard turning is more beneficial practical process compared to a grindingoperation, it increases quality, reduces cost and lead-time formachined parts. In this study, effects of workpiece hardness,feed rate, depth of cut and cutting speed on surface roughnesswere studied using chamfered and honed CBN inserts. Fourfactors (hardness, depth of cut, feed rate and cutting speed)were considered and - two level fractional experiments wereconducted and analysis of the variance was performed.Furthermore this study shows that the effects of grinding ofheat treated AISI D2 specimens on surface roughness wereconducted and a comparison took place with hard turning. To investigate the effect temperature increase on bothtechniques, the machined surface of workpieces is examinedusing optical and scanning electron microscopy SEM.Practical results shows the lower workpiece hardness andlower cutting conditions resulted in a better surface roughness. Finally results showed that in hard machining not only themachining parameters have an influence on the surfaceroughness but also the material hardness found effective factorin finishing process.

Corrosion protection of mild steel by superhydrophobic magnetite coating

Corrosion-resistant hydrophobic magnetite coatings on mild steel surfaces were developed by immersion method. The effect of steel surface roughness (Ra) on its hydrophobicity was systematically studied using contact angle measurement (CAM), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The corrosion resistance of hydrophobic magnetite coatings was evaluated using a potentiodynamic polarization test. The durability of the coatings was assessed in air, tap water, and 3.5 wt% NaCl environments. Hydrophobic magnetite coating with a water contact angle of 146-152° showed excellent resistance to corrosion, longevity in atmospheric air, and significant self-cleaning properties. The primary focus of this study was to develop a quick and simple immersion technique to create hydrophobic surfaces on mild steel. Results suggest that surface roughness plays a significant role in surface hydrophobicity, and enhancing the hydrophobicity of mild steel improves its corrosion resistance.

The effects of deposited layer thickness on the material and geometrical properties of L-DED processed AISI D2 tool steel

ABSTRACT This research focuses on the influences of the deposited layer thickness upon the material characteristics, dimensional accuracy, and also the surface roughness of AISI D2 tool steel processed by laser directed energy deposition (L-DED); while layer thickness was varied, the remaining L-DED system parameters were retained at fixed values. After laser deposition, the D2 specimens were assessed without applying any subsequent machining steps. Sample dimensional accuracy was assessed through both manual measurement and computational methods, with the latter using confocal laser scanning microscopy (CLSM). It was shown that increasing the layer thickness decreases the extent of sample overbuilding. The use of lower layer thicknesses reduced the top surface roughness. However, a monotonic effect was not observed for side surface roughness in relation to the deposited layer thickness. In addition, the microstructures of the L-DED samples were evaluated using a combination of scanning electron microscopy (SEM) with associated energy dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). It is shown that a dendritic morphology is formed for the L-DED processed samples, with a columnar grain structure. Furthermore, the primary crystalline phase generated with the dendritic structure was found to be austenite. The indentation hardness values for the L-DED fabricated parts were noted to be larger for thinner deposited layer thicknesses.

Examining the impact of slide burnishing parameters on the 3D surface features of medium carbon steel

Burnishing is a non-cutting finishing technique in which pressure is applied to plastically deform the irregularly distributed surface materials. In this process, the peaks of the surface are pressed into the valleys with a hard tool, resulting in a smoother surface with improved properties. The influence of brunishing parameters such as brunishing force, feed rate and number of passes on the 3D surface roughness of medium carbon steel was analyzed. An orthogonal L9 array Taguchi design was used to create a robust experiment. A CNC milling machine and a confocal microscope were used to grind and measure the workpiece surface. The topography roughness responses Sq, Sv, Sz and Sa were used to evaluate the roughness changes. The optimal parameters for brunishing were a feed rate of 0.05 m/min, 2 passes and a force of 80N for Sq and Sa and a force of 100N for Sv and Sz. This research is expected to provide insights into optimizing mass finishing processes to improve surface integrity, contributing to advances in manufacturing and materials science.

Synergistic mixture of Camellia Oleifera shell extract and KI as an eco-friendly and highly efficient composite inhibitor for steel corrosion in H2SO4 media

To address the severe corrosion problems faced by steel, a natural corrosion inhibitor derived from Camellia Oleifera shell extract (COSE) was developed. The effectiveness of COSE as well as its synergistic mixture of COSE/KI in inhibiting the corrosion of steel in H2SO4 was investigated using weightlessness and electrochemical techniques. The results show that the maximum inhibition efficiency of individual COSE is 77.28 % at 20 °C, and is increased to 93.08 % for the mixture of COSE/KI. The adsorption of COSE, KI and COSE/KI on steel surface conform to Langmuir adsorption isotherm. COSE/KI has a stronger adsorption than either COSE or KI. Electrochemical analysis indicates that COSE/KI is a hybrid inhibitor primarily focusing on the cathodic inhibition. Mixing COSE with KI shows considerably larger charge transfer resistance and smaller double-layer capacitance than individual COSE and KI. Characterization tests such as metallurgical microscopy, SEM, AFM and contact angle confirm that the addition of COSE/KI could reduce the roughness of steel surface, while increase the hydrophobicity, then effectively alleviate the corrosion on the steel surface. XPS analyses demonstrated that the corrosion inhibition layer on the steel surface was induced by the adsorption of the polar groups in COSE. The components responsible for COSE’s effectiveness were thoroughly examined using FTIR and liquid chromatography-mass spectrometry (LC-MS), which identified the presence of compounds such as flavonoids and phenylpropanoids. The synergistic effect of the active ingredients (rutin, quercetin, tea saponin, tea polyphenols, et al.) with KI was also confirmed. Finally, theoretical calculations were conducted to analyze properties of rutin, quercetin and tea polyphenols on the iron layer. The results show all these molecules exhibit efficient inhibition, with quercetin showing better inhibitive ability by parallel adsorption.

Unveiling the effect of electron beam shock on the microstructure and wear resistance of Cr12MoV steel

Enhancing wear resistance is the core factor that prolonged the life of the Cr12MoV mold and elevates the quality of the components produced. Hence, Cr12MoV mold steel was shocked by scanning electron beam (SEB) to improve wear resistance. Results revealed that the segregation eutectic carbides in the surface structure of Cr12MoV steel were dissolved during the shock process of various beam electron beams, and the small particles of carbides produced are helpful in reducing wear. With an energy density of 20 J/mm2, surface roughness of Cr12MoV steel decreases from 2.9 μm to 1.2 μm, the friction coefficient decreases from 0.85 to 0.52. Additionally, the wear capacity also decreases from 0.036 mm3 to 0.011 mm3, and surface wear resistance increases by over 3 times. Grain refinement-induced surface hardening is the primary cause underlying performance improvement. This study provides ideas for improving the surface quality of Cr12MoV steel.

Synergistic effect of ZnO nanocomposite of Dodonea viscosa for corrosion inhibition in saline media

Abstract Dodonea viscosa-zinc oxide (DV-ZnO) nanocomposite was synthesized and characterized using Fourier transform infrared (FTIR), thermal gravimetric method (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). The most abundant compounds in the plant extract were explored using gas chromatography-mass spectrometry (GC-MS). FTIR indicated the existence of the different functional groups, XRD showed that the nanocomposite has the hexagonal wurtzite shape of ZnO nanoparticles, SEM-EDS showed a size of 50 nm, and elemental analysis depicts the existence of the different elements in the extract, which confirms, along with TGA results, the formation of DV-ZnO nanocomposite. The nanocomposite synergistic effect was examined for anticorrosion capabilities using gravimetric, electrochemical, and surface analysis methods. Both the plant extract and the nanocomposite exhibited corrosion inhibition abilities. However, the incorporation of the plant extract with ZnO increased the inhibition efficiency by 20 %. Weight loss and electrochemical methods concluded an inhibition efficiency of 80 % for DV-ZnO nanocomposite. The inhibition of the nanocomposite is due to the adsorption of the inhibitor on the carbon steel surface, which was verified using X-ray photoelectron spectroscopy and scanning electron microscopy (SEM). The adsorption was found to follow both Langmuir and Temkin isotherms. Surface examination using atomic force microscopy (AFM) found that the carbon steel surface roughness was decreased from the sample submerged in an uninhibited medium (Sa = 121.20 nm) when adding DV-ZnO nanocomposite (Sa = 22.95 nm) and DV plant extract inhibitor (Sa = 54.73 nm).

Comparative study of surface roughness between electropolishing process and traditional sanding for low carbon steel

Steel is a versatile material utilized across various sectors, encompassing both industrial and decorative applications. AISI (American Iron and Steel Institute) 1005 steel, recognized for its low carbon content (approximately 0.05% carbon), is commonly referred to as mild steel and finds extensive use in society. This study aims to investigate the influence of electropolishing parameters, specifically current density, and time, on the surface roughness of steel. The methodology involved the preparation of samples for electropolishing tests, systematic variation of the parameters, and subsequent analysis of the resulting surface finish through roughness measurements. Samples subjected to higher current densities for shorter durations exhibited substantial reductions in roughness, while longer durations resulted in minimal or negligible changes in roughness regardless of the current density employed. This comparative analysis between electropolishing and tradi-tional sanding techniques provides valuable insights into optimizing surface finishing processes for low carbon steel applications.