Stainless Steel Type Research Articles

Influence of Compressive Strength and Steel-Tube Thickness on Axial Compression Performance of Ultra-High-Performance Concrete-Filled Stainless-Steel Tube Columns Containing Coarse Aggregates

With the increasing use of concrete-filled steel tubular (CFST) structures, exposed steel tubes are highly susceptible to corrosion, posing potential safety hazards. This study innovatively proposes the use of stainless-steel tubes instead of traditional carbon-steel ones and introduces coarse aggregates into ultra-high-performance concrete (UHPC), forming a coarse aggregate-incorporated ultra-high-performance concrete-filled stainless-steel tube (CA-UFSST). The inclusion of coarse aggregates not only compensates for the shortcomings of UHPC but also enhances the overall mechanical performance of the composite structure. Twenty sets of specimens were designed to analyze the influence of four parameters, including the coarse aggregate content, compressive strength, stainless-steel-tube thickness, and stainless-steel type on the axial compression performance of UHPC. The experimental results indicate that the failure mode of UHPC is related to the confinement ratio. As the confinement ratio increases, the failure mode transitions from shear failure to bulging failure. The addition of coarse aggregates enhances the stiffness of the specimens. Furthermore, this paper discusses the applicability of six current codes in predicting the bearing capacity of CA-UFSST and finds that the European code exhibits the best prediction performance. However, as the confinement ratio increases, the prediction accuracy becomes notably insufficient. Therefore, it is necessary to establish a more accurate calculation model for the axial compression bearing capacity.

Orthodontic Alloy Wires and Their Hypoallergenic Alternatives: Metal Ions Release in pH 6.6 and pH 5.5 Artificial Saliva.

Legislative framework addresses the issues of alloy corrosion, demanding the restricted use of probable carcinogenic, mutagenic, and toxic-for-human-reproduction (CMG) metals like nickel, cobalt, and chromium and demanding the development of new biomaterials. The aim of this research was to evaluate and compare the ion release of standard dental alloys and their hypoallergenic equivalents. Six types of orthodontic alloy wires (nickel-titanium (NiTi), coated NiTi, stainless steel (SS), Ni-free SS, and cobalt-chromium (CoCr) and titanium-molybdenum (TMA) were immersed into artificial saliva of pH 5.5 and 6.6. Release of metal ions was measured by inductively coupled plasma-mass spectrometry after 3, 7, 14 and 28 days. The data were analyzed using analysis of variance, and results with p < 0.05 were considered significant. NiTi released more Ti and Ni ions compared to the coated NiTi; SS released more iron, chromium, and nickel compared to the nickel-free SS. CoCr released cobalt in a high concentration and low amounts of chromium, nickel, and molybdenum compared to the molybdenum and titanium released by TMA. Release of metals from dental orthodontic alloys in vitro was overall lower at pH 6.6 and for the hypoallergenic equivalents when compared to standard dental alloys.

Experimental and numerical study of dissimilar fiber laser welding of martensitic AISI 1060 carbon steel with different configuration with austenitic 304 and ferritic 420 stainless steel

Welding with fiber laser for two distinct stainless steel types was performed to join with the martensitic carbon steel (AISI 1060) in order to assess the effect of laser welding operating parameters for two dissimilar materials on the weld characterization thorough experimental design method and numerical investigation. A full central composite design (CCD) matrix in accordance with the response surface methodology (RSM) was developed to represent the responses variations by equations including quadratic and nonlinear interaction terms. Different laser welding parameters were taken into account, such as laser power, linear speed of welding, focal distance of the beam, and beam deviation. The responses considered were the temperature field next to the melt pool border line, the maximum penetration depth of the fusion zone and the ultimate tensile strength of the dissimilar weld joint. Additionally, the variation of the microstructure fusion zone and adjacent areas and failure mechanism of the weld joint were evaluated. The experimental results indicate that the temperature field measured at the vicinity of the melt pool fusion line with both 304 and 420 stainless steel which primarily influenced by the incident power of the laser and linear velocity of beam, respectively. Additionally, the numerical simulation results are in good agreement with temperature experimental results at vicinity of fusion line where the temperature measured, experimentally. Apart from this, at the center of the fusion zone, the temperature clearly predicts via numerical simulation results which is not possible to assess experimentally. A clear comparison between the temperature distribution with different joint configuration illustrates that distinct relation between the temperature variation rate and different thermal conductivity coefficient of AISI 1060 with different AISI 304 and 420 joint configuration resulted different temperature distribution. The weld joint microstructure for 420 stainless steel–AISI 1060 steel joint at fusion boundary zone consists of columnar dendrites and skeletal columnar ferrite. At the center of fusion zone, a cellular-type structure is seen. For 304 stainless steel joint, the fusion zone has composed of a remarkable part of skeletal delta-ferrite and dendritic microstructure at austenite matrix microstructure. The fracture section of 304 steel has a ductile fracture and the depth of fracture dimples and cavities toward 304 stainless steel are higher than AISI 1060 steel.

Substrate and potential-driven surface morphology of bifunctional Ni-Fe electrode for efficient alkaline water electrolysis

Nickel-iron (Ni-Fe) alloy electrodes are synthesized using chronoamperometry. The influence of substrate type (copper, stainless steel, and nickel) and deposition potential on the structural, morphological, and electrocatalytic characteristics are systematically investigated. X-ray diffraction (XRD) analysis revealed the formation of a face-centered cubic (FCC) Ni-Fe alloy. Electrodeposition at higher potential (−1.45 V) forms well-defined nanoflakes, whereas electrodeposition at lower potential (−1.00 V) results aggregated Ni-Fe particles. The Ni-Fe alloy electrodes having well-defined nanoflakes demonstrated superior electrocatalytic performance, exhibiting a overpotential of −168 mV vs. RHE for the hydrogen evolution reaction (HER) and 236 mV vs. RHE for the oxygen evolution reaction (OER), at current density of 10 mA/cm2. The enhanced electrocatalytic activity of the nanoflakes based Ni-Fe alloy is attributed due to their larger catalytic surface area, porous morphology and higher Fe concentration. The Ni-Fe alloy electrodes displayed bifunctional electrocatalytic behavior, making them highly suitable for both HER and OER processes.

Electrochemical, gravimetric and surface studies of Phalaris canariensis oil extract as corrosion inhibitor for 316 L type stainless steel in H2O-LiCl mixtures

The corrosion inhibition action of Phalaris canariensis extract on 316 L stainless steel in the H2O-35 (wt%) LiCl mixture at different temperatures has been evaluated with the aid of weight loss, potentiodynamic polarization curves, linear polarization resistance and electrochemical impedance spectroscopy tests. These studies were complemented by Fourier Transformed Infrared spectroscopy, FTIR, gas/mass chromatography analytical techniques and detailed scanning electronic microscopy studies. Results have indicated that Phalaris canariensis extract is an efficient inhibitor, with an efficiency that increases with its concentration, but it decreases as the temperature increases. Phalaris canariensis extract is physically adsorbed onto stainless steel according to a Temkin type of adsorption isotherm. Phalaris canariensis extract affected both anodic and cathodic electrochemical reactions with a stronger effect on the anodic ones, acting, thus, as a mixed type of inhibitor. Main compounds contained in the Phalaris canariensis extract were palmitic and oleic acids, responsible for its inhibitory properties.

Mechanical effect of different patterns for preparation of orthodontic appliances: An experimental study.

Archwire bending is the key to orthodontic treatment, and multi-time bendings are inevitable during manual and robotic automated bending. The purpose of this paper is to quantitatively evaluate the mechanical effects of the different preparation modes and to compare the mechanical properties of the orthodontic loops in one and multiple bends. Three types of typical stainless steel orthodontic loops (vertical loop, T-loop, and L-loop) were used to quantify the mechanical effect of patterns for preparation by experimental comparison between loops with different bending times by using an orthodontic force tester (OFT). The results were statistically analyzed by t-test. The fracture test of the stainless steel archwire was also carried out, and the bending times at fracture were recorded. Results of the tests indicate that one-time and multi-time bending have a significant mechanical effect on orthodontic appliances. Multi-time bending causes significant mechanical decreases and can damage the appliances.

Assessment of Various Archwire Materials and Their Impact on Orthodontic Treatment Outcomes.

Aim Orthodontic treatment relies heavily on the mechanical properties and surface characteristics of archwire materials to achieve optimal outcomes. This study aimed to comprehensively evaluate the mechanical properties, including tensile strength, yield strength, and modulus of elasticity, as well as the surface characteristics, such as surface roughness and frictional properties, of different archwire materials. Methods Four types of archwire materials, stainless steel, nickel-titanium (NiTi), beta-titanium, and esthetic archwires, were subjected to mechanical testing and surface analysis, with 31 in each group. Tensile testing was conducted to determine the maximum tensile strength, yield strength, and elastic modulus of each material. Surface roughness analysis was performed using profilometry techniques, and frictional properties were evaluated using an orthodontic friction testing apparatus. Results Stainless steel exhibited the highest tensile strength (900 N), followed by beta-titanium (850 N), NiTi (800 N), and esthetic archwire (750 N). Stainless steel also demonstrated the highest yield strength (780 N), followed by beta-titanium (740 N), NiTi (710 N), and esthetic archwire (650 N). The modulus of elasticity was the highest for stainless steel (200 GPa), followed by beta-titanium (170 GPa), NiTi (150 GPa), and esthetic archwires (120 GPa). Surface roughness was lowest in stainless steel archwires (mean Ra value of 0.25 µm), leading to reduced frictional resistance, whereas esthetic archwires exhibited the highest surface roughness (mean Ra value of 0.40 µm) and frictional forces. Significant differences in the mechanical properties and surface characteristics were observed among the materials (p < 0.05). Conclusions The choice of archwire material significantly influences orthodontic treatment outcomes by affecting the efficiency and effectiveness of tooth movement. Stainless steel and beta-titanium wires are ideal for high-stress applications, providing the robust mechanical strength necessary for complex movements. In contrast, NiTi wires, with their superelasticity, offer consistent and gentle forces, enhancing patient comfort and accelerating the alignment phase. Esthetic archwires, while visually appealing, often compromise mechanical performance, potentially prolonging treatment duration.

Effect of Powder Reuse on Powder Characteristics and Properties of DED Laser Beam Metal Additive Manufacturing Process with Stellite® 21 and UNS S32750

In this work, the influence of powder reuse up to three times on directed energy deposition (DED) with laser processing has been studied. The work was carried out on two different gas atomized powders: a cobalt-based alloy type Stellite® 21, and a super duplex stainless steel type UNS S32750. One of the main findings is the influence of oxygen content of the reused powder particles on the final quality and densification of the deposited material and the powder catch efficiency of the laser deposition process. There is a direct relationship between a higher surface oxidation of the particles and the presence of oxygen content in the particles and in the as-built materials, as well as oxides, balance of phases (in the case of the super duplex alloy), pores and defects at the micro level in the laser-deposited material, as well as a decrease in the amount of material that actually melts, reducing powder catch efficiency (more than 12% in the worst case scenario) and the initial bead geometry (height and width) that was obtained for the same process parameters when the virgin powder was used (without oxidation and with original morphology of the powder particles). This causes some melting faults, oxides and formation of undesired oxide compounds in the microstructure, and un-balance of phases particularly in the super duplex stainless steel material, reducing the amount of ferrite from 50.1% to 37.4%, affecting in turn material soundness and its mechanical properties, particularly the hardness. However, the Stellite® 21 alloy type can be reused up to three times, while the super duplex can be reused only once without any major influence of the particles’ surface oxidation on the deposited material quality and hardness.

Study of the Effect of Initial Plate Temperature in Jet Impingement Cooling Process

The microstructure characteristics and the properties of rolled steels are significantly affected by the heat transfer and boiling phenomena occurring during the jet impingement cooling on run‐out tables (ROT). In this study, experiments are conducted using a full industrial‐scale ROT facility with rectangular plates made of low‐carbon stainless steel (type 316L). The plate is heated up to a temperature ranging from to , then rapidly impinged using a single circular water jet, and the temperature drop is captured using an infrared thermal camera (FLIR A615 25°–50 Hz type). The dissipated heat flux, estimated experimentally using a 2D inverse heat conduction analysis, ranges from 6.1 to 3.4 MW m−2 across different zones along the plate surface. The impact of different initial plate temperature on the boiling behavior is studied by developing a 2D‐computational fluid dynamics (CFD) model, and the results are closely aligned with the experimental findings. The results reveal that when estimating the heat flux from CFD simulations, the best accuracy is obtained when considering fluid temperature at a point close to the plate surface (about 1 μm above the surface). Furthermore, the maximum extracted heat flux (MHF) is significantly influenced by the initial temperature of the plate. Increasing the initial plate temperature from 500 to 900 °C led to an increase of 82% in the MHF in stagnation zone, and 137% increase in the parallel‐flow region. The CFD model presented in this study and the full calculation of the boiling curves numerically will pave the road for investigating various practical parameters in jet impingement cooling.

Solid‐State Bonding of Iron or Steel with Stainless Steels by Spark Plasma Sintering Bonding

In this study, pure iron, S45C carbon steel (Fe–0.45mass%C), carburized iron, and nitrided iron are bonded with two types of stainless steels, i.e., SUS304 austenitic stainless steel (Fe–18mass%Cr–8mass%Ni) with face center cubic structure or SUS430 ferritic stainless steel (Fe–18mass%Cr) with body center cubic structure by a spark plasma sintering (SPS) machine. Bonding experiments are carried out by SPS bonding. It is found that the bonding temperature of the S45C/SUS samples is lower than that of Fe/SUS samples, and carbon atoms in the S45C play important role on the bonding performance. The bonding temperature for SUS304/SUS430 sample is more than 30 °C higher than those for the Fe/SUS and S45C/SUS samples. The presence of thin chromium oxides on both stainless steels reduces the bonding performance of SUS304/SUS430 sample. Better bonding performance is found for the carburized and nitrided iron for bonding with stainless steels. However, continuous single‐phase layer on the surface leads to reduce the bonding performance. It is concluded that not only the concentration of carbon and nitrogen but also the phase configuration in the iron at interface strongly influences the bonding performance between iron alloys and stainless steels by SPS bonding.

Hydrogen Embrittlement Properties of Austenitic Stainless Steel Type 316L Welded Joint

Hydrogen Embrittlement Properties of Austenitic Stainless Steel Type 316L Welded Joint

Influence of gamma radiation on self-assembled molecular layers developed on different metals

In this work, self-assembled molecular layers (SAMs), developed from special amphiphilic molecules (undecenyl phosphonic acid) on the top of two types of stainless steels (1.4571 and 1.4841) were in focus. The metal surface was modified by a self-assembled molecular layer with a double bond at the end of the carbon chain. The modification of the structure of the unsaturated hydrophobic chain was done by gamma irradiation to produce a more compact layer. We were interested in the influence of the metal composition on the layer formation. To give answers to these questions SAM layers were deposited on the top of the stainless steels and then the nanolayers were modified by post-treatment (gamma irradiation). The thickness of the surface films was characterized by ellipsometry and the composition of the amphiphilic SAM layers by infrared spectroscopy. Atomic Force Microscope (AFM) visualized the morphological changes due to the layer deposition and the post-treatment; the surfaces were numerically characterized by roughness parameters; contact angle values proved the change in the wettability caused by the metal surface and the gamma irradiation.

Experimental study on compressive capacity of stainless steel S35657 columns with welded box section and I-section under axial compression

Compared with conventional stainless steel, a new type of stainless steel, S35657, has broad application prospects owing to its advantages of high strength and low production costs. In this study, the compressive capacity of stainless steel S35657 columns was investigated. A total of 13 specimens were designed and tested, including 4 box section specimens and 9 I-section specimens (4 buckling around the major axis and 5 buckling around the minor axis). Complementary chemical composition analyses, material tensile tests, residual stress measurements, and initial geometric imperfection measurements were also conducted. The mechanical properties of the material, as well as its residual stress distribution model, failure mode, load-displacement curve, and compressive capacity, were reported and analyzed. For box section columns, when the slenderness ratio increased from 29 to 55.2, the compressive capacity of the column decreased by 27.6 %. The accuracy and safety of design methods specified in European standard EN 1993–1–4, American specification ASCE-8–02, and Chinese specification CECS 410 were assessed based on the test results. The result shows that EN 1993–1–4 is overly conservative in its compressive capacity calculations, whereas ASCE-8–02 overestimates the compressive capacity with a higher level of scatter exhibited. The methods of CECS 410 for predicting the compressive capacity of welded stainless steel S35657 columns are more accurate compared with the methods of EN 1993–1–4 and ASCE-8–02.

EVALUATING ACETONE AND METHANOL FOR ELECTROPHORETIC DEPOSITION OF SS 316L COATED WITH HYDROXYAPATITE/MULTIWALLED CARBON NANOTUBES DENTAL IMPLANTS: A FOCUS ON CORROSION RESISTANCE

Dental implants offer a reliable solution for replacing damaged tooth roots. This research investigates the comparative performance of acetone and methanol as suspension media in the fabrication of stainless steel type 316L-based dental implants using the Electrophoretic Deposition (EPD) method, a technique known for its simplicity and cost-effectiveness. Voltage variations of 20V, 30V, and 40V were applied to both acetone and methanol suspensions for a duration of 20 minutes. The morphology of the Hydroxyapatite/Multiwalled Carbon Nanotube (HA/MWCNT) coatings was meticulously characterized using Scanning Electron Microscopy (SEM). Corrosion resistance was evaluated through Potentiodynamic Polarization (PDP) and Electrochemical Impedance Spectroscopy (EIS) techniques. Remarkably, at 30V, a homogeneous and crack-free coating was achieved, demonstrating superior corrosion resistance. This was further corroborated by the resistance values of 23.891 Ω and 114.990 Ω for the acetone and methanol samples, respectively. Additionally, the corrosion rates of 0.075 (mmpy) and 0.0004 (mmpy) for the acetone and methanol samples further emphasized the superiority of methanol as a suspension medium. These findings unequivocally establish methanol as the optimal choice for achieving superior deposition quality and corrosion resistance in the context of the EPD method for stainless steel type 316L-based dental implants.

Mengoptimalkan Analisis Sifat Mekanik Material Berbasis Data Dengan Pandas Profiling

The analysis of mechanical properties based on data is a method used to analyze the mechanical properties of a material using data, typically obtained from a material database. This process encounters several challenges, such as large volume of data, complexity in data processing, as well as difficulties in data visualization and interpretation. In this study, Pandas Profiling, a Python library designed specifically for automated dataset analysis, was employed. The dataset used consisted of tensile test results for various austenitic stainless steel types such as SUS 304, SUS 316, SUS 321, SUS 347, and NCF 800H. This dataset comprised 1916 samples with attributes related to mechanical properties and factors influencing them. The analysis results using Pandas Profiling indicated a strong negative correlation between heat treatment temperature and Yield Strength (YS) and Ultimate Tensile Strength (UTS). Additionally, a positive correlation was found between chemical elements such as Copper (Cu) and Nickel (Ni) with Elongation (EL). Furthermore, the analysis results revealed that stainless steel treated with water cooling exhibited a higher average UTS value, measuring at 493 MPa, compared to air cooling, which only reached 403 MPa. Pandas Profiling offers an effective solution to overcome common challenges in data-based mechanical property analysis, including dealing with large data volumes, complex data processing, as well as challenges in data visualization and interpretation. By utilizing Pandas Profiling, researchers can easily comprehend the dataset comprehensively, identify patterns, trends, and relationships among variables, and optimize the analysis process of data-based material mechanical properties.

Experimental Study on Corrosion of Stainless Steel in Low Temperature Multi effect Seawater Desalination

Starting from the corrosion mechanism, this paper analyzes the characteristics of various types of stainless steel and selects the best performance composite plate composite plate stainless steel. Analyze and select the most suitable corrosion detection method based on specific practical multi working conditions, discuss the interference factors that affect metal corrosion during experimental simulation, and the advantages of newly developed sheet metal. The new development of composite board panels, with the substrate and composite materials applying their respective capabilities for MED, will bring breakthrough progress to the scientific research and engineering application of composite boards.

Effect of high-temperature molten salt corrosion on the mechanical properties of stainless steel

The corrosivity of molten salt can be detrimental to the safe operation and longevity of concentrated solar thermal power generation equipment. Additionally, the presence of impurity Cl− can increase corrosion on metal materials, leading to mechanical property degradation. To assess the extent of this effect, the corrosion behaviour of three types of stainless steel (304, 316L, and 347H) in molten salt at high temperatures was studied using the loss-in-weight method and tensile tests. According to the findings, the Rdepths of 304, 316L, and 347H stainless steels are 0.0018 mm/a, 0.0016 mm/a, and 0.0019 mm/a, respectively, resulting in a decrease in elongation of 12.2%, 7.0%, and 3.7% after 720 h of corrosion at 600°C. Furthermore, at a higher temperature of 680°C, the Rdepths of all stainless steels increased, and the elongation decreased by 25.4%, 18.9%, and 13.5%, respectively. Similar corrosion behaviour was observed in 347H stainless steel with increased chloride ion concentration. However, the yield strength and tensile strength of stainless steel did not exhibit significant changes under different experimental conditions. The corrosion mechanism of metal alloys in molten salt is mainly due to the selective corrosion of Cr and its dissolution into molten salt in the form of ions.

Enhanced Spectroscopic Insight into Acceptor-Modified Barium Strontium Titanate Thin Films Deposited via the Sol-Gel Method.

In the present paper, composite thin films of barium strontium titanate (BaxSr1-xTiO3) with an acceptor modifier (magnesium oxide-MgO) were deposited on metal substrates (stainless steel type) using the sol-gel method. The composite thin films feature BaxSr1-xTiO3 ferroelectric solid solution as the matrix and MgO linear dielectric as the reinforcement, with MgO concentrations ranging from 1 to 5 mol%. Following thermal treatment at 650 °C, the films were analyzed for their impedance response. Experimental impedance spectra were modeled using the Kohlrausch-Williams-Watts function, revealing stretching parameters (β) in the range of approximately 0.78 to 0.89 and 0.56 to 0.90 for impedance and electric modulus formalisms, respectively. Notably, films modified with 3 mol% MgO exhibited the least stretched relaxation function. Employing the electric equivalent circuit method for data analysis, the "circle fit" analysis demonstrated an increase in capacitance from 2.97 × 10-12 F to 5.78 × 10-10 F with the incorporation of 3 mol% MgO into BST-based thin films. Further analysis based on Voigt, Maxwell, and ladder circuits revealed trends in resistance and capacitance components with varying MgO contents, suggesting non-Debye-type relaxation phenomena across all tested samples.

Effect of high-strength and stainless steel reinforcement on the flexural behavior of UHPC beams

Ultra-high performance concrete (UHPC) is an advanced cement-based composite which shows remarkable properties including very high compressive strength, increased tensile resistance, impressive toughness and excellent durability. One promising application of UHPC is in heavily-loaded beams and slabs where its use can allow for increased design efficiency and improved durability. Conversely, the high bond capacity of UHPC can lead to early bar fracture failures, especially when using low amounts of ordinary steel reinforcement. This paper examines the influence of reinforcement grade on the flexural ductility of UHPC beams. As part of the study, three beams built with either Grade 400 MPa ordinary steel reinforcement, Grade 690 MPa high-strength reinforcement or Grade 520 MPa stainless steel reinforcement, are tested under flexural loading. The key test parameters include the influence of concrete type (UHPC vs. conventional high-strength concrete) and steel type (high-strength or stainless steel vs. ordinary steel). The results show that the flexural strength and ductility of the UHPC beams is influenced by the steel grade/type. The beam with ordinary steel shows a well-defined yield point but fails by bar rupture. Increased resistance by 47% is observed when using high-strength bars, however bar rupture occurs owing to the low strain-capacity of this steel type. Combining UHPC with higher ductility stainless steel does not increase capacity, but leads to remarkable ductility by 75%. As part of the numerical study the behaviour of the beams is predicted using FE modelling and the effects of tension steel ratio, UHPC tensile strength and high-strength or stainless steel type are investigated.

Damages in the Type-316 Stainless Steel Loading Device Used for SCC Tests in the Simulated Nuclear Power Water

Damages in the Type-316 Stainless Steel Loading Device Used for SCC Tests in the Simulated Nuclear Power Water