Stainless Steel Research Articles

Temperature and plastic strain dependent Chaboche model for 316 L used in simulation of cold pilgering

Cold pilgering is a complex forming process used to produce seamless tubes, posing significant challenges in material modeling due to its non-proportional loading history and extensive accumulated plastic strain. In this study, a temperature- and plastic strain-dependent Chaboche model for 316 L stainless steel was developed and calibrated. To simulate the complex loading conditions, unique alternating compression-compression tests were conducted, and the model parameters were optimized accordingly. The calibrated model was integrated into a thermo-mechanical finite element simulation of the cold pilgering process, resulting in improved accuracy in predicting stress-strain responses and yield stress evolution. Close agreement with experimental tensile tests of the final tube was demonstrated, illustrating the model’s capability to predict hardening behavior during cold pilgering. Valuable insights and a practical modeling approach for enhancing the simulation and optimization of cold pilgering processes are provided by this work.

Synthesis of Cu doped Ba(OH)2 thin film by SILAR method for supercapacitor electrode application

Abstract An economically suitable successive ionic layer adsorption and reaction (SILAR) method has been used to deposit 0.25, 0.50 and 0.75 wt% copper doped barium hydroxide on stainless steel (SS) substrate. X-ray diffraction analysis shows the orthorhombic crystal structure of Cu doped Ba(OH)2 electrode. FTIR analysis reveals the chemical bonds present in the sample. The energy-dispersive x-ray spectroscopy (EDAX) and x-ray photo electron spectroscopy (XPS) measurements have been performed to confirm Cu doping into Ba(OH)2. The electrochemical properties of Cu doped Ba(OH)2 electrode have been analysed by cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) techniques. The 0.50 wt% Cu doped barium hydroxide electrode exhibits the highest specific capacitance (Csp) of 356.12 F g−1 (59.55 mF cm−2) at 1 mV s−1 scan rate in 1 M Na2SO4 electrolyte solution. This electrode also shows ~ 85% capacitance retention up to 8000 cycles. A symmetric device has also been fabricated by using two electrodes. This device shows energy and power densities of 1.13 Wh Kg-1 and 279.7 W Kg-1 respectively. This cyclic retention and capacitive behaviour of Cu-doped Ba(OH)2 shows its utility as an energy storage material in the near future.

Optimization of machining parameters while turning AISI316 stainless steel using response surface methodology

The chromium-nickel alloy known as AISI 316 Stainless Steel is extensively used in various industries, such as the chemical industry, nuclear power plants, and medical devices, due to its exceptional mechanical properties and corrosion resistance. Compared to other stainless steels, AISI 316 resists corrosion from air and other corrosive conditions better. Determining the optimal selection of machining parameters is still a challenge for many researchers. The Box Behnken technique (L12 array) is used in this work to design the experiment set. Response surface methodology (RSM) is used to examine how the cutting velocity (100, 150, and 200 m/min), feed (0.10, 0.15, and 0.20 mm/rev), and depth of cut (02, 0.4, and 0.6 mm) affect the cutting force (Fc), surface roughness (SR), power consumption (Pw), and tool life (T). The ANOVA investigation shows that cutting force and surface roughness increase linearly with an increase in feed. Similarly, power consumption and tool life also increase linearly with an increase in cutting velocity. The best combination for the lowest Fc, SR, and Pw and the maximum T is cutting velocity at 122.37 mm/min, feed at 0.13176 mm/rev, and cut depth at 0.213337 mm. For cutting force, surface roughness, power consumption, and tool life, the actual and predicted values are (124.31, 129.45), (0.55, 0.57), (1.131, 1.154), and (2112, 2225), respectively. For the lowest feasible values of Fc, SR, Pw, and maximum T, the optimal settings are a cutting speed of 122.37 mm/min, feed of 0.13176 mm/rev, and depth of cut of 0.213337 mm.

Effect of Pulsed Current Treatment on Microstructure and Properties of 304 Stainless Steel Ultra-Thin Strip after Rolling

The annealing process is usually used to heat-treat cold-deformed 304 stainless steel to improve its microstructure and properties to a certain extent; however, it requires a high temperature and a long time. Because the thickness of the ultrathin strip reaches the micrometer level, it has only one or several layers of grains in the thickness direction, and the control of morphology and performance is complex. In this study, pulsed current loading was used to replace traditional annealing for treating ultrathin strips of cold-rolled 304 stainless steel. After loading a 25 W pulsed current treatment for 5 min on the cold-rolled sample, which had a thickness of 0.035 mm and width of 6 mm, complete recrystallization occurred, and the mechanical properties were significantly improved. At this point, the measured temperature was 540 °C. When annealing was used to treat the sample with the same temperature and for the same duration, the microstructure was still dominated by deformed crystals, and the mechanical properties were poor. When annealing was used to obtain a microstructure and properties similar to those obtained via 25 W electrical treatment, the required annealing temperature and time were 810 °C and 60 min, respectively. Pulsed current can increase the vacancy diffusion flux in the sample, accelerate the atomic movement, reduce the recrystallization activation energy, and make the cold-rolled 304 stainless steel ultrathin strip completely recrystallize at a lower temperature and in a shorter time. As the current power continued to increase, the recrystallized grains grew. When the pulsed current power was increased to 25 W, the recrystallized grains grew negligibly. Both recrystallization and grain growth have power thresholds. This study provides a novel approach for regulating the microstructure and mechanical properties of ultrathin cold-rolled 304 stainless steel strips.

Card-type Piezoelectric Energy Harvesters of Pb(Zr,Ti)O3 Thin Films on Stainless Steel Foils

Card-type Piezoelectric Energy Harvesters of Pb(Zr,Ti)O3 Thin Films on Stainless Steel Foils

Cleaning methods for biosafety cabinet to eliminate residual mycoplasmas, viruses, and endotoxins after changeover

IntroductionCell-processing operations can potentially contaminate biosafety cabinets, which should be maintained sterile. However, unintended contamination can occur owing to the presence of viruses, mycoplasmas, and bacteria in the raw materials. Moreover, although several methods for expunging these contaminants have been proposed, an optimal method has not yet been determined. Additionally, the effectiveness of conventional methods for eliminating these contaminants remains unclear owing to their unique characteristics and potential resistances to cleaning. Therefore, this paper proposes a risk-based approach to identify appropriate cleaning methods and reduce the likelihood of cross-contamination in biosafety cabinets by these contaminants. MethodsVarious cleaning methods for eliminating mycoplasmas, viruses, and endotoxins from biosafety cabinets were evaluated, including ultraviolet (UV) irradiation at 200 mJ/cm2 for 20 min and wiping with disinfectants such as distilled water, benzalkonium chloride (BKC), and 70 % ethanol (ETH). The effectiveness of each method was evaluated by applying the contaminants on stainless steel plates and cleaning them using each method. Mycoplasma orale was cultured for 2 weeks in a liquid medium after cleaning. Feline calicivirus (FCV) was used for evaluating the virus-cleaning effectiveness and its presence was tested using the TCID50 test, whereas endotoxins obtained from the dried extract of Escherichia coli were measured via endotoxin testing. ResultsUV irradiation and wiping with BKC inhibited the growth of mycoplasma and significant decreased their presence compared with the other cleaning methods. Notably, mycoplasma were detected after wiping all SUS304 plates with ETH, which is a widely used cleaning method. Additionally, the cleaning efficacy for virus showed that the TCID50 of the wet group was 132,000 TCID50/plate, whereas those after UV irradiation or cleaning with BKC or DW were below the detection limit. Finally, UV irradiation did not significantly reduce the endotoxin production compared with that in the dry group. Additionally, wiping with ETH did not significantly reduce endotoxins compared with the dry group and their residues were higher than those detected after wiping with BKC or DW. ConclusionsThe changeover protocols currently employed in most cell-processing facilities may be ineffective as pathogenic or nonpathogenic materials may remain even after ETH wiping, leading to unintended cross-contamination. To the best of our knowledge, this is the first study to provide reference data of different cleaning methods for mycoplasmas, viruses, and endotoxins in cell-product manufacturing facilities, and can potentially support the development of evidence-based management strategies for ensuring safe cell-product processing.

A Comparison of Localized Corrosion Behavior of Hastelloy X and Stainless Steel 316 in Persian Gulf Costal Water

A Comparison of Localized Corrosion Behavior of Hastelloy X and Stainless Steel 316 in Persian Gulf Costal Water

Finite Element Simulation and Experimental Analysis of the Thermo-Mechanical Properties of Dissimilar S275 and 316L Austenite Stainless Steels using the RFW Process

This research examines the effect of thermomechanical and microstructural constituents on welding of AISI 316L (austenite stainless steel) and S275 steel. A Finite Element Model (FEM) was constructed using ANSYS 19.1, and an experimental study was conducted using the Rotary Friction Welding (RFW) process. It was determined that there is a genuine correlation between the simulation FEM and the experimental procedure with regard to the thermal profile and ultimate yield strength, particularly when a welding speed of 2,000 rev/min is employed. At that speed, the higher temperature recorded and calculated was 1,450 oC. The discrepancy between the numerical FEM and the experimental temperature profile for the peak temperature calculation was determined to be 2.78%. The mechanical analysis was conducted through tensile force calculations and experiments, the results of which indicated an estimated error of 12%. The calculated error for the ultimate yield strength of the various samples is less than 6% for tensile strength. Upon tensile testing, failure occurred in the S275 sample. The microstructure exhibited increases in Cr and Ni of 1.2% and 1.01%, respectively, in comparison to the base metal of 316L stainless steel.

Development of ZrO2-Coated SPME Fibers for Detecting Benzotriazole Ultraviolet Filters in Water Samples

In this study, the zirconium dioxide nanoparticles (ZrO2NPs) were coated on the surface of stainless steel (SS) by cyclic voltammetry (CV) as solid phase microextraction fiber coating for detection of the benzotriazole ultraviolet filters (BUvFs) in different real water samples. The composition and images of the new SS@ZrO2NPs fiber were characterized by scanning electron microscopy (SEM). The extraction capability of SS@ZrO2NPs fiber was investigated for the enrichment and detection of benzotriazole ultraviolet filters (BUvFs) phthalate acid esters (PAEs) and polycyclic aromatic hydrocarbons (PAHs) coupled with HPLC. The fabricated SS@ZrO2NPs fiber showed excellent extraction selectivity and good extraction capability for BUvFs. Under the optimized conditions, the SS@ZrO2NPs-SPME method presented linear ranging from 0.15 to 200 µg/L with correlation coefficients of higher than 0.9982. Moreover the limits of detection (LODs) varied from 0.020 µg/L to 0.138 µg/L. Relative standard deviations (RSDs) with single fiber were below 7.78% and 8.91% for intra-day and inter-day measurements, respectively. The developed method was used to the detection of trace BUvFs in different real water samples.

Characterization of Particle Fluidization in a New Type of Fluidized Bed Flotation Unit

ABSTRACTUnderstanding the hydrodynamics of the bed layer in a fluidized bed is essential for optimizing and improving fluidized bed flotation units. This study proposes a fluidized bed flotation column that incorporates auxiliary particles into the gas–liquid two‐phase system to address the shortcomings of traditional flotation units. Stainless steel particles (glass beads), tap water, and compressed air were used as the solid, liquid, and gas phases, respectively. Key factors affecting the bed hydrodynamics (such as bed fluctuation, minimum fluidization velocity, bed expansion, and porosity) in the fluidized column include gas and liquid flow rates as well as the initial bed height. Experimental results show that selecting appropriate filling particles can effectively enhance the fluidization performance of the bed, while appropriately increasing the gas flow rate can achieve fluidization at lower liquid velocities, thus reducing energy consumption during the flotation mineralization process. Theoretical analysis combined with extensive data reveals that the expansion characteristics of the fluidized bed and the use of high‐density filling particles can effectively mitigate bed layer fluctuations and stabilize the flow field environment. Additionally, based on a wide range of data, this study employs model factor analysis, dimensionless analysis, and multiple linear regression analysis to propose a standard dimensionless parameter model for the fluidized bed flotation column, which can effectively predict bed layer fluctuations and expansion characteristics.

Cyclic and torsional fatigue resistance of two replicalike and original brand reciprocating system

The aim of this study was to evaluate the cyclic and torsional fatigue resistance of two replicalike in comparison of the original brand reciprocating system. Material and methods: A total of 60 reciprocating instruments were used to perform the cyclic and torsional fatigue test of following systems: Reciproc Blue 25.08 (RB 25.08), Only One File Blue (OFB 25.08) and RC Blue 25.08 (RCB 25.08) (n=20). The cyclic fatigue test was performed using an artificial stainless steel canal with 60º angle of curvature and a 5-mm radius of curvature. The instruments were activated until failure occurred. The time to failure (TF) and number of Cycles to failure (NCF) were evaluated. The torsional test was performed following the ISO 3630-1. Three millimeters of the instrument tip was fastened to a small load cell and the maximum torsional strength and angular deflection were recorded using the torsion testing machine software. The fractured surface of each instrument was assessed by scanning electron microscopy (SEM). The data were analyzed using one-way analysis of variance ANOVA and Tukey’s test for Multiple comparisons at a significance level of 5%. Results: The cyclic fatigue tests demonstrated that OFB 25.08 had the highest TF and NCF than among the groups (P<0.05). RCB 25.08 exhibited lowest TF and NCF (P>0.05). Regarding the torsional test, the RCB 25.08 and OFB 25.08 had the highest torque than the other groups (P<0.05). Additionally, RB 25.08 and OFB 25.08 exhibited highest angular deflection values than the other groups (P><0.05). Conclusion: The OFB 25.08 demonstrated highest TF and NCF than the instruments tested. The RCB 25.08 exhibited lowest cyclic fatigue resistance and angular deflection.> P<0.05). RCB 25.08 exhibited lowest TF and NCF (P>0.05). Regarding the torsional test, the RCB 25.08 and OFB 25.08 had the highest torque than the other groups (P<0.05). Additionally, RB 25.08 and OFB 25.08 exhibited highest angular deflection values than the other groups (P><0.05). Conclusion: The OFB 25.08 demonstrated highest TF and NCF than the instruments tested. The RCB 25.08 exhibited lowest cyclic fatigue resistance and angular deflection.> P<0.05). Conclusion: The OFB 25.08 demonstrated highest TF and NCF than the instruments tested. The RCB 25.08 exhibited lowest cyclic fatigue resistance and angular deflection.

Laser surface cladding of stainless steel to substitute environmentally hazardous hard chrome plating

Laser surface cladding of stainless steel to substitute environmentally hazardous hard chrome plating

In Situ Synchrotron X-ray Diffraction Analysis During Post-Weld Heat Treatments of Supermartensitic Stainless Steel Weld Metal

In Situ Synchrotron X-ray Diffraction Analysis During Post-Weld Heat Treatments of Supermartensitic Stainless Steel Weld Metal

Comparative analysis of the effectiveness of instrumentation with manual stainless steel and NiTi files in the endodontic treatment

The aim of this study was to assess the effectiveness in instrumentation and the main differences between the manual systems K and M. Material and methods: Forty Type IV Vertucci standardized lower molars, considering the degree of curvature, were divided into 2 groups (n=10): M Files and K-File Files. After biomechanical preparation, the teeth were filled using the Tagger Hybrid technique. Digital radiographs were taken in the buccolingual and mesiodistal directions, and the quality of the filling was determined by three calibrated and blinded evaluators using a 4-point scoring system. The instrument fracture index was also recorded. The obtained data were subjected to Mann-Whitney tests (p<0.05). Results: In the analysis conducted by experienced professionals, a higher radiographic quality of obturation was observed in the M file group compared to the K-file group (p<0.05). Regarding the perception of undergraduate students regarding the difficulty of procedures, a greater difficulty was observed in preparing molars with K-Files compared to M Files (p<0.05). A higher percentage of fractured K-Files was observed compared to M Files. Conclusion: M Files provided less difficulty in preparing molars for undergraduate students, had a lower incidence of fracture, and favored better radiographic quality of obturation.

The ability of austenitic stainless steel (Alloy-28) to withstand corrosion when exposed to a combination of industrial phosphoric acid and an oxidizing agent

The ability of austenitic stainless steel (Alloy-28) to withstand corrosion when exposed to a combination of industrial phosphoric acid and an oxidizing agent

A comparative analysis of different surface tribological and electrochemical properties of TiAlN, TiAlSiN, and CrAlN thin film coatings in seawater

Abstract To reveal the wear mechanisms of TiAlN, TiAlSiN, and CrAlN coatings in a seawater environment, the changes in frictional surfaces and the electrochemical characteristics of these coatings were compared and analyzed in this paper. The coatings were deposited on 316L stainless steel surfaces. Tribological tests were investigated using a ball-on-disk tribometer with Si3N4 ceramic balls as the counter material. Although the friction coefficient of 316L stainless steel was the lowest at 0.34, the order of wear rates was 316L stainless steel (7.38×10-5)>TiAlN(5.31×10-6)>TiAlSiN(4.23×10-6)>CrAlN(1.10×10-6) and the electrochemical protective efficiencies of TiAlSiN and CrAlN were both greater than 97%. Seawater penetrated through the grain boundaries of the TiAlN coating, which led to corrosion and delamination failure. Conversely, the grain refinement in TiAlSiN and CrAlN coatings can significantly slow down the penetration of seawater into the coating under frictional pressure, and the oxide lubricating layer formed during the friction process can become an effective barrier to isolate seawater. Therefore, mechanical wear was the main wear form of these two coatings. Additionally, among the oxides formed in the friction, Cr2O3 showed the strongest corrosion resistance, making the CrAlN coating exhibit superior wear resistance and the lowest wear rate in seawater.

Deposition Strategy on Microstructure Development and Mechanical Properties of Wire Arc Additively Manufactured Austenitic Stainless Steel

Deposition Strategy on Microstructure Development and Mechanical Properties of Wire Arc Additively Manufactured Austenitic Stainless Steel

A novel late-stage oscillating discharge current for plasma regulation and its effect in material removal in electrical discharge machining

Abstract Improving the material removal rate (MRR) has recently become one of the most important issues in electrical discharge machining. During the discharge process, a large portion of molten material cannot be sufficiently expelled from the molten pool but re-solidifies, ultimately resulting in low energy utilization and machining efficiency. Unlike existing methods that primarily focus on optimizing general discharge parameters, this study aims to enhance molten material expulsion and MRR through discharge plasma regulation by employing a redesigned late-stage oscillating discharge current. During a single-pulse discharge process, this kind of discharge current firstly remains constant to ensure stable heat transfer from the plasma to the workpiece, then transitions to periodic oscillations to enhance plasma movement and facilitate molten material expulsion. High-speed plasma observations and heat-flow coupling simulations are conducted to analyze the effects of the discharge currents on material removal, and the optimal oscillation start time is obtained. Experimental results in machining stainless steel demonstrate that the use of the late-stage oscillating discharge current, in comparison to the conventional rectangular discharge current, results in a 74% increase in material removal volume per unit of energy and a 56% in average recast layer thickness.

Performance prediction of 304 L stainless steel based on machine learning

With the development of testing technology and data mining methodologies, machine learning (ML) has been widely applied for predicting the performance of materials in various systems including stainless steel with improved performance. To address the limitations of traditional experimental and statistical methods in predicting the thermal deformation of materials, a predictive machine learning model was developed based on the data obtained from thermal simulation compression tests. Specifically, the Arrhenius and the Modified Johnson-Cook (J-C) Constitutive Model were developed utilizing experimental data to initially predict the rheological behavior of 1.52% Cu-304L stainless steel. Then, a physical metallurgy (PM)-guided Back Propagation (BP) model was developed, and Genetic Algorithm (GA), Whale Optimization Algorithm (WOA), and Mind Evolutionary Algorithm (MEA) were incorporated into the model for optimization purposes, respectively. Finally, the results indicate that the PM-MEA-BP model exhibits superior predictive performance, accurately forecasting the texture evolution of 304L stainless steel with random crystal orientation under rolling deformation conditions. Additionally, the present work also clearly demonstrated that the model not only satisfies precision requirement but also has certain guiding significance for optimizing process parameters and forecasting the microstructure and properties of stainless steel.

Effects of Beads and Shot Peening Intensity on the Surface Integrity and Fatigue Performance of a Stainless Gear Steel

Shot peening was performed on stainless gear steel using multiple kinds of beads at multiple intensities. The effects of shot peening on surface integrity and the rotational bending fatigue performance were tested with the crack origin location observed. The results showed that the average surface roughness increases from Sa0.408 μm to Sa1.165 μm as the shot peening intensity increases, which does not necessarily lead to an increase in surface stress concentration coefficient. The compressive residual stress profile and the depth of the hardened layer increase with the increase of shot peening intensity. During ceramic bead peening, the fatigue improvement, with a maximum of 25 times, increases with the raise of intensity (0.06–0.20 mmA), while the fatigue improvement decreases when intensity (0.2–0.30 mmA) increases using cast steel shot. Based on ceramic shot peening, a method was proposed to predict the origin location of rotational bending fatigue cracks of gear stainless steel, in which the effects of surface stress concentration, compressive residual stress, and external load introduced were all considered. By using the superposition method of external load and residual stress, the maximum actual stress corresponding depth is obtained, which is the origin position of the rotational bending fatigue crack.