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1

Enhancement of the corrosion resistance for stainless steel 316 by applying laser shock peening

Jasim Sarah A., Ayesh Ammar, Kadhim A., Abdullah Oday I.

Polish Journal of Chemical Technology

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2024

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Vol. 26, nr 1

1--7

EN

This research paper focuses on enhancing the surface characteristics of the 316 stainless steel (SS316) alloy, including roughness, microhardness, and corrosion resistance. Where the application of ND-YAG laser technology, a highly relevant and timely area, was investigated deeply. The Q-switching Nd: YAG Laser was used with varying laser energy levels within the context of the laser shock peening (LSP) technique. The corrosion resistance of the 316 ss alloy is evaluated in a corrosive environment of 500 mL of saliva (with a pH of 5.6) through electrochemical corrosion testing. Corrosion rate was determined based on the analysis of polarization curves. The outcomes of this research reveal that as the laser energy was increased, there was a noticeable enhancement in the mechanical properties of the 316 ss alloy’s surface. Importantly, the corrosion rate experiences a significant reduction, decreasing from 4.94 mm/yr to 3.59 mm/yr following laser shock peening (LSP) application.

2

Enhanced wear and corrosion performance of stainless steel 316L with addition of different weight percentages of GNP

Veeramallu Kalyanamanohar, Krishna Alluru Gopala

Composites Theory and Practice

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2024

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R. 24, nr 1

25--32

EN

The present study reports on the significant improvement in the wear and corrosion resistance of SS316L by adding Graphene nanoplatelets (GNP) of varying wt.% (0.25, 0.5, and 0.75), composites which were prepared by the pressureless sintering technique. The GNP addition can significantly improve the wear and corrosion resistance of SS316L. The wear and corrosion rates for the 0.5 wt.% GNP composite were reduced by 43% and 98%, respectively. The corrosion morphology showed that pitting corrosion was reduced by reinforcing 316L with 0.5 wt.% GNP. Moreover, the intergranular sites were more vulnerable to the corrosion medium when GNP was used at 0.75 wt.%. The worn surface morphology revealed that the tribofilm reduces the coefficient of friction and wear rate due to the lubricating nature of GNP. The presence of GNP was confirmed by Raman spectroscopy in terms of the tribofilm.

3

Pulse frequency density modulation full bridge for induction preheating application of stainless-steel welding

Chakkuchan P., Chudjuarjeen S., Phankong N.

Archives of Materials Science and Engineering

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2024

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Vol. 127, nr 1

23--31

EN

Purpose: The paper shows the problem of surface cracks from welding (TIG welding) to welding stainless steel pipe (heat-affected zone: HAZ). The study is an experiment of preparing welding with non-heating workpieces and preheating the workpiece using the principle of induction, heating with a fluid inverter circuit that can adjust power by frequency control, pulse frequency density modulation (PFDM) to maintain temperature for industrial. Design/methodology/approach: The control circuit is responsible for regulating the functioning of different devices and the speed of operation of the switch device. It divides the control into two closed loops: phase-angle feedback and current feedback. The phase-angle feedback loop ensures frequency tracking during the phase check angle, enabling the inverter to operate at frequencies higher than the resonant frequency throughout its operation. The process of arc welding was employed in the fusion of stainless-steel materials. Preheating is a crucial step in the welding process, as it serves to uphold the integrity of the weld and mitigate the occurrence of undesirable outcomes such as cracking and the subsequent requirement for rework. The Welding Process Specification (WPS) about the task at hand will delineate the lower and upper limits of preheating temperatures and the requisite period for preheating. High-quality products should be devoid of these imperfections and possess comprehensive welding reinforcement. Additional welding certifications encompassed a tensile testing procedure, a microhardness testing procedure, and a comprehensive microstructure analysis. Findings: Applying an alternating voltage to an induction coil generates an alternating current (AC) within the coil circuit. The induced currents exhibit a frequency identical to that of the coil current, although they possess an opposite direction to the coil current. These currents facilitate heat generation through the phenomenon known as the Joule effect. The temperature range of 250°C-400°C can be effectively regulated for preheating stainless steel by using high-frequency electric process heating in induction welding, hence achieving the desired welding preheat. There are two primary classifications for inverters: voltage-source inverters and current-source inverters. Research limitations/implications: The main research limitation is comparing preheat and non-preheat. The size of the heat-affected zones is influenced by the rate of heating and cooling brought on by machining processes. By influencing the microstructural changes in that area, precise control of the variables can impact the integrity of the weld zones. The microstructural characteristics of the metal are different from the rest of the subject because welding heats the metal. The topic is heated up beforehand to ensure smooth welding and structural integrity. Because there is less of a temperature difference between the weld zone and the base material, preheating during welding results in less shrinkage stress. Distortions and crack flaws might result from higher shrinkage stress. Practical implications: NDT, or non-destructive testing, is a weld integrity test to find defects that occur in the weld without damaging that welding line and continuing to use it safely. For the welding line to be strong according to the design of that welding line (conformance to design), the test will use the principles of physical properties, such as light, X or gamma rays, magnetic fields, and high-frequency sound waves. Originality/value: In the research, stainless steel was successfully welded to preheat using induction heating (IH).

4

Influence of L-PBF additive manufacturing parameters on the residual stresses and thermal distortions in AISI 316L stainless steel parts

Santos O., Batalha G.F., Farias V., Seriacop V., Bordinassi E.C., Adamiak M.

Archives of Materials Science and Engineering

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2024

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Vol. 127, nr 1

12--22

EN

Purpose: The work aimed to numerically model through the Finite Element Method (FEM) the distribution of residual stresses and thermal distortions in parts generated by Laser Powder Bed Fusion (L-PBF) in stainless steel AISI 316L and validate the results obtained through experimental measurements on previously manufactured parts. Design/methodology/approach: The design methodology followed a numerical approach through the Finite Element Method (FEM), the distribution of residual stresses and thermal distortions in parts generated by Selective Laser Powder Bed Fusion (L-PBF) in stainless steel AISI 316L and the FEM approach was validated trough the results obtained through experimental measurements on previously manufactured parts. The influence on three levels was verified through complete factorial planning of some manufacturing parameters, such as laser power, speed, and distance between scans (hatch), on the stress and distortion results of the samples and also on the samples simulated by FEM. Findings: When results were compared about the average diameters, a relative error of less than 2.5% was observed. The average diameter was influenced by power and speed. Increasing power decreased the average diameter of the samples, while increasing speed and hatch increased the average diameter. When results are compared to measure the residual stresses, it is observed that the relative error was less than 1%. Power, speed, and the hatch itself influenced the residual stress. Increasing power increases residual stress while increasing speed and hatch decreases residual stress. The cooling rate and the transient thermal history are the control factors that influence the residual stresses and are directly related to the process parameters. The computational modelling followed by measurements and calibrations carried out in the experimental stages proved to be efficient and enabled the reproduction of thermal distortion and residual stresses with statistical confidence. prediction of thermal distortions and residual stresses using the machine learning approach. Future research will study heating the building platform, which should also impact residual stresses. Practical implications: Based on the results obtained in this research, it will be possible to select better additive manufacturing parameters for manufacturing 316L stainless steel parts. The parameters evaluated in the work were laser power, scanning speed, and hatch. Originality/value: The innovation of the work lies in the robust simulation of the thermo-elastic behaviour of samples subjected to the additive manufacturing process, where it was possible to accurately relate the thermal distortions and residual stresses that appeared in the samples printed with the parts modelled by the FEM. The numerical-experimental validation makes it possible to extrapolate the studies to several other manufacturing parameters using only computational simulation and work with a more significant amount of data for a prediction study.

5

Microstructure, Mechanical Properties, and Heat Distribution ANSYS model of CP Copper and 316 Stainless Steel Torch Brazing

Abtan Auday Awad, Mohammed Mohammed S., Alshalal Iqbal

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no 1

167--183

EN

Using torch brazing techniques, 316 stainless steel was brazed to CP copper using flux-coated low silver content filler with 20% Ag. The brazing torch utilized a fuel mixture of propane gas with oxygen to produce the required heating amount due to the possibility of economic interest in employing low-silver-content filler. The brazing filler's braze ability with SUS304 and copper was scrutinized and deeply analyzed. A ferrite barrier layer was made on the stainless-steel side, and an excellent brazed joint was produced. Metallurgical studies using an optical microscope and a scanning electron microscope (SEM) confirmed the production of a ferrite layer. This layer's advantages were carefully examined with metallurgical testing, electron diffraction scanning (EDS), EDS mapping, and EDS line analyses, including preventing copper intergranular penetration into the stainless-steel grain boundary. The mechanical properties of the brazed joint and its usability were assessed through Vickers microhardness and tensile tests on the brazing seam and both base metals. The results of the brazing process showed that using flux-coated low-silver brazing techniques produced strong joints with satisfactory mechanical properties. These techniques are a cost-effective alternative to high-priced brazing fillers with high silver content. Geometrical models simulated the heat distribution using ANSYS and SOLIDWORKS software to analyze penetration depth, joint quality, surface cracks, and the relation between molten filler density variation and the wetting process.

6

Effect of floating-plug drawing process parameters on surface finish of inner and outer surfaces of AISI 321 stainless steel thin-walled tubes

Żaba Krzysztof, Szpunar Marcin

Advances in Mechanical and Materials Engineering

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2024

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Vol. 41, nr 1

27-37

EN

This article presents the results of the analysis of changes in the surface topography of AISI 321 (1.4541) thin-walled stainless steel tubes in single-pass Floating-Plug Drawing (FPD) process. Experimental tests were carried out with variable drawing speed (1, 2, 3, 4, 6, and 10 m/min) and different angles of floating plug (11.3°, 13° and 14°). Wisura DSO7010 (Fuchs Oil) lubricant was used in the experiments. Mean roughness Ra and ten point height of irregularities Rz were adopted as surface quality indicators. Roughness parameters were measured independently on the inner and outer surfaces of thin-walled tubes. Analysis of variance was used to analyse the relationship between process parameters (drawing speed and angle of floating plug) and surface roughness of tubes. A decrease in the values of both analyzed roughness parameters was observed as a result of the drawing process. The FPD process significantly improves the inner surface quality of AISI 321 thin-walled stainless steel tubes. The mean roughness value tends to increase with increasing drawing speed, while the angle of the floating-plug has no significant effect on the mean roughness Ra.

PL

W artykule przedstawiono wyniki analizy zmian topografii powierzchni rur cienkościennych ze stali nierdzewnej AISI 321 po procesie ciągnienia na korku swobodnym. Badania eksperymentalne przeprowadzono w jednym przejściu, ze zmienną prędkością ciągnienia (1, 2, 3, 4, 6, and 10 m/min) oraz różnymi kątami β korka swobodnego (11.3°, 13° and 14°). W badaniach eksperymentalnych wykorzystano smar Wisura DSO7010 (Fuchs Oil). Jako wskaźniki jakości powierzchni przyjęto średnie arytmetyczne odchylenie rzędnych profilu Ra oraz wysokość chropowatości według 10 punktów Rz. Parametry chropowatości mierzono niezależnie na wewnętrznej i zewnętrznej powierzchni rur cienkościennych. Do analizy związków pomiędzy parametrami procesu ciągnienia (prędkość ciągnienia i kąt korka swobodnego) wykorzystano analizę wariancji. Zaobserwowano zmniejszenie wartości obydwu analizowanych parametrów chropowatości w wyniku procesu ciągnienia. Proces ciągnienia na korku swobodnym znacznie poprawia jakość wewnętrznej powierzchni cienkościennych rur ze stali nierdzewnej AISI 321. Zaobserwowano tendencję do zwiększania się parametru Ra wraz ze wzrostem prędkości ciągnienia, podczas gdy kąt β korka swobodnego nie miał znaczącego wpływu na średnią chropowatość Ra.

7

Study of the Mechanical and Antibacterial Properties of Surface Modified Steel for Medical Applications

Taratuta Anna, Lisoń-Kubica Julia, Kazek-Kęsik Alicja, Antonowicz Magdalena, Basiaga Marcin

Tribologia

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2023

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nr 2

85--95

EN

Various types of metal implants, both in Poland and worldwide, are mainly manufactured from stainless steel due to their biocompatibility, strength, and relatively low price. However, any such procedure involves the risk of peri-implant infection, stimulated, among other things, by the formation of a bacterial biofilm on the surface of the implant. In this paper, several methods of modifying the surface of steel for medical applications were proposed, such as mechanical polishing, electropolishing, sandblasting, and the application of a thin surface layer. This was followed by a series of physicochemical and biological tests. The results indicate that the titanium nitride coating improved corrosion resistance and reduced bacterial adhesion on the surface. No significant improvement in abrasion was observed, and the adhesion of the coating closely depended on the method of preparation.

PL

Implanty metalowe, zarówno w Polsce, jak i na świecie, produkowane są głównie ze stali nierdzewnej ze względu na jej biokompatybilność, wytrzymałość i stosunkowo niską cenę. Jednak każdy tego rodzaju zabieg wiąże się z ryzykiem powstania zakażenia okołowszczepowego, stymulowanego m.in. powstawaniem biofilmu bakteryjnego na powierzchni implantu. W pracy zaproponowano kilka metod modyfikacji powierzchni stali do zastosowań medycznych, takich jak polerowanie mechaniczne, elektropolerowanie, piaskowanie oraz nałożenie cienkiej warstwy powierzchniowej. Następnie przeprowadzono szereg badań fizykochemicznych i biologicznych. Wyniki wskazują, że powłoka azotku tytanu poprawiła odporność na korozję oraz ograniczyła adhezję bakterii na powierzchni. Nie zaobserwowano znaczącej poprawy ścieralności, a adhezja powłoki ściśle zależała od metody jej przygotowania.

8

Dynamic Behaviour of Selective Laser Melted 316L Steel : Mechanical Properties and Microstructure Changes

Białobrzewski Paweł, Sienkiewicz Judyta, Janiszewski Jacek, Kluczyński Janusz

Problemy Mechatroniki : uzbrojenie, lotnictwo, inżynieria bezpieczeństwa

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2023

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Vol. 14, Nr 2 (52)

51--72

EN

316L steel specimens with three different shear zones made by SLM (Selective Laser Melting) were subjected to dynamic tests using the Split Hopkinson Pressure Bar method. The effect of high-speed deformation on changes in microstructure was analyzed. In addition, the stress-strain relationship was determined from the SHPB results. To visualize the deformation process of the specimens during the tests, a camera with a high frame rate was used. It was shown that as the plastic deformation increases, the hardness of the material increases. Microstructural analysis of dynamically loaded areas revealed numerous defects. Twinning was found to be the main deformation mechanism. Large plastic deformation and many other microstructural changes such as shear bands, cracks and martensite nucleation were also observed.

PL

Próbki ze stali 316L z trzema różnymi strefami ścinania wykonane metodą SLM (Selective Laser Melting) poddano testom dynamicznym wykorzystując do tego metodę dzielonego pręta Hopkinsona (Split Hopkinson Pressure Bar). Przeanalizowano wpływ odkształceń o dużej szybkości na zmiany w mikrostrukturze. Ponadto na podstawie wyników badań SHPB wyznaczono zależność naprężenie- odkształcenie. W celu zobrazowania procesu odkształcania próbek podczas badań zastosowano kamerę o dużej częstości klatkowania. Wykazano, że wraz ze wzrostem odkształcenia plastycznego wzrasta twardość materiału. Analiza mikrostrukturalna obszarów obciążonych dynamicznie ujawniła liczne defekty. Stwierdzono, że głównym mechanizmem deformacji jest bliźniakowanie. Zaobserwowano również duże odkształcenia plastyczne i wiele innych zmian mikrostruktury, takich jak pasma ścinania, pęknięcia i zarodkowanie martenzytu.

9

Material Production and the Effect of the System on Biocompatibility in the Modified Metal Injection Method

Çiçek Bünyamin, Sun Yavuz

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 1

195--204

EN

In this study, the bio state of the alloy produced in the modified metal injection system was monitored after sintering. A new system operating with high gas pressure, far from the traditional injection model, has been established for material production. In this system, 316L stainless steel powders were molded using a PEG/PMMA/SA polymer recipe. During molding, approximately 60% 316L and 40% binder by volume were used. The samples obtained were sintered at different temperatures (1100-1300°C) after de-binding. Density measurement (Archimedes) and hardness tests (HV1) of the samples were measured as 6.74 g/cm3 and ~285 HV1, respectively. A potentiodynamic corrosion test was applied to monitor the effect of the amount of oxide in the structure of the 316L stainless steel produced. Corrosion tests were carried out in artificial body solutions. The corrosion rate was measured at the level of 17.08×10-3 mm/y. In terms of biocompatibility, a cytotoxicity test was applied to the samples and the life course of the bacteria was monitored. For the 316L alloys produced, the % vitality reached approximately 103%.

10

Acoustic Emission and Infrared Thermography Study of Low Strain Tensile Behaviour of AISI 304L Stainless Steel

Sapietová Alžbeta, Raček Marek, Dekýš Vladimir, Sapieta Milan, Sága Milan, Šofer Pavel

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 2

463--468

EN

In-situ study of deformation behaviour and mechanisms occurring during early stages of deformation is of a great practical importance. Low stacking fault energy materials, as is the case of AISI 304L, show non-linear deformation characteristics way below the bulk yield point. Shockley partial dislocations, formation of stacking faults respectively, resulting in creation of shear bands and ε-martensite transformation are the mechanisms occurring in the low strains in the studied steel. Acoustic emission and infrared thermography have been used in this study to investigate the deformation kinetics at the low strain stages of slow strain rate tensile tests. Acoustic emission cumulative energy together with the tracking of specimen maximum temperature have been found to be very useful in-situ techniques both supplementing each other in the sense of the sensitivity to different mechanisms. Mechanical, acoustic emission and infrared thermography results are discussed in detail with respect to potential occurred mechanism.

11

Effect of surfactant concentration in modifying solution on corrosion properties of the coatings based on vinyltrimethoxysilane (VTMS) and poly(3,4-ethylenedioxythiophene) (PEDOT)

Kucharczyk A., Adamczyk Lidia, Miecznikowski K.

Archives of Materials Science and Engineering

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2023

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Vol. 121, nr 1

5--17

EN

Purpose: This paper presents an analysis of the structure and physicochemical properties of coatings based on an organofunctional silane (VTMS), a conductive polymer (PEDOT), and a surfactant (polyoxyethylene glycol monolauryl ether BRIJ). Design/methodology/approach The coatings were deposited on X20Cr13 stainless steel and glassy carbon specimens using sol-gel immersion. The obtained coatings were characterised in terms of topography, microstructure, roughness, adhesion to the steel substrate, thickness, and corrosion resistance. Corrosion tests were conducted in sulfate environments with pH = 2 without or with the addition of Cl- ions. Findings: The use of different surfactant concentrations in the modifying solution is intended to improve the deposition efficiency and increase the degree of dispersion of silane and conducting polymer. Research limitations/implications The tested coatings were found to slow down the corrosion of the steel substrate, thus effectively protecting it from this phenomenon. The use of a surfactant compound is intended to increase the degree of dispersion of silane and polymer in the modifying solution to improve deposition efficiency. Practical implications: Test carried out in corrosive media have shown that the coatings proposed in the above work, based on VTMS silane, PEDOT polymer and BRIJ surfactant, significantly increase the corrosion resistance of the tested materials, which confirms their effectiveness and possibility of application in various industries. Originality/value: The novelty of this paper is the use of silane (VTMS), polymer (PEDOT) and surfactant (BRIJ) as components of the anticorrosion coating.

12

Additive manufacturing of metallic biomaterials: a concise review

Mahajan Amit, Singh Gurcharan, Devgan Sandeep

Archives of Civil and Mechanical Engineering

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2023

|

Vol. 23, no. 3

art. no. e187, 2023

EN

Additive manufacturing (AM) is one of the critical techniques of novel medical devices which is capable of processing complicated or customized structures to best match the human’s bones and tissues. AM allows for the fabrication of devices with optimal architectures, complicated morphologies, surface integrity, and regulated porosity and chemical composition. Various AM methods can now consistently fabricate dense products for a range of metallic, nonmetallic, composites, and nanocomposites. Different studies are available that describe the microstructure and various properties of 3D-printed biomedical alloys. However, there are limited research on the wear characteristics, corrosion resistance, and biocompatibility of 3D-printed technology-constructed biomedical alloys. In this article, AM metallic biomaterials such as stainless steel, magnesium, cobalt–chromium, and titanium are reviewed along with their alloys. The helicopter view of essential characteristics of these additively manufactured biomaterials is comprised. The review will have a significant impact on fabricating metallic surgical equipment and its sturdiness in the biomedical field.

13

Surface Characteristics and Wear Resistance of 316L Stainless Steel after Different Shot Peening Parameters

Walczak Mariusz

Advances in Science and Technology. Research Journal

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2023

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Vol. 17, no 3

124--132

EN

The study was conducted to evaluate the effect of ZrO2-based ceramic beads shot peening on the performance properties of AISI 316L austenitic steel. The results obtained in the roughness and microhardness measurements, the state of the surface layer, and the tribological properties (ball-on-disc) of the specimens after the peening process were compared to the results obtained for the reference specimen. The tests were carried out with varying parameters of pressure (0.3 MPa, 0.4MPa) and time (30s, 60s). The lowest values of COF (µ=0.576) and wear factor (K=3.95*10-4 mm3N-1m-1) were observed for the surface peened using parameters: 0.4 MPa and 60s. By increasing the time twice, a much lower wear factor can be achieved unlike when increasing the shot peening by 0.1 MPa. Observations of wear traces indicate that abrasive wear is predominant and the transfer of specimen material by countersample is also observed.

14

Corrosion behavior of austenitic stainless steels in road salt solutions

Zatkalíková Viera, Markovičová Lenka, Valčuhová Daniela

Zeszyty Naukowe Akademii Morskiej w Szczecinie

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2022

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nr 71 (143)

72--77

EN

Stainless steels are widely used for various automotive components. Some of them (e.g., parts of the exhaust system) are exposed to the external environment. In winter conditions, they are affected by chloride containing road salt solutions, which can lead to the local corrosion of these stainless steel parts. The presented paper is focused on the pitting corrosion resistance of two austenitic stainless steels (AISI 304 and AISI 316L) in 5 wt% and 10 wt% road salt solutions. The evaluation and comparison are based on the potentiodynamic polarization test method carried out at the temperature of 20 ± 2°C. The pitting potentials were determined from the polarization curves. Local corrosion damage of exposed surfaces caused by potentiodynamic polarization in the used solutions was observed by optical microscope. Experimental results confirmed a worse pitting corrosion resistance case, especially for AISI 304 stainless steel in 10 wt% road salt solution.

15

Modeling and optimization of friction stir stitching of AISI 201 stainless steel via Box-Behnken design methodology

Ojo Olatunji Oladimeji, Obasha Isaac Ojo

Production Engineering Archives

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2022

|

Vol. 28, Iss. 2

132--140

EN

The paper investigates the modelling and optimization of the notch-repaired/friction stir stitched AISI 201 stainless steel welds via the use of a non-consumable tool-based repair process. The repair process employs a sequential hopping-stitching approach. This approach involves the application of two intercepted and completely overlapped plunging actions of a probe-less titanium carbide tool to create an effective refilling and repair of the notched zone. Box-Behnken design (BBD) was employed for the experimental planning, modelling, and optimization of the notch-repair process. Tool rotational speed, penetration depth and dwell time of the tool were the studied process parameters while tensile strength was the response variable. A quadratic model was identified as the best model for the notch-repaired welds based on the combination of a low sequential P-value of 0.008216, a high lack of fit P-value of 0.931366, and a close to unity adjusted and predicted R-square values. The process parameter and their interaction effects on the tensile strength of the repaired notch were identified via the ANOVA analysis. Plunge depth (main effect) and interaction effect of tool rotational speed and dwell time had significant influences on the notch-repair process and the resultant tensile strength of the AISI 201 stainless steel. The visual representations of these effects were shown through the 2D elliptical contour and 3D response surface plots. The optimized process parameters were identified as 1215.9795 rpm, 0.40262212 mm, and 5.98706376 s while the resultant notch-repaired joint yielded a tensile strength of 886 MPa, which is close to the predicted value.

16

Wpływ stężenia BRJI na właściwości ochronne powłok silanowych na bazie winylotrójmetoksysilanu wytworzonych na stalach X20Cr13 i 41Cr4

Kucharczyk Aleksandra, Adamczyk Lidia

Ochrona przed Korozją

|

2022

|

nr 3

83--87

PL

W niniejszej pracy zbadano właściwości ochronne powłok silanowych na bazie winylotrójmetoksysilanu VTMS i niejonowego środka powierzchniowo - czynnego BRJI. Jako rozpuszczalnik organosilanu i surfaktantu zastosowano etanol, natomiast kwas octowy zastosowano w celu ustalenia środowiska kwasowego (pH roztworów między 3−4). Powłoki naniesiono na próbki stali nierdzewnej X20Cr13 oraz stali stopowej konstrukcyjnej 41Cr4 metodą zanurzeniową w procesie sol-gel przy użyciu różnych stężeń surfaktantu. Otrzymane powłoki scharakteryzowano pod względem odporności korozyjnej, przyczepności do podłoża stalowego oraz grubości. Badania korozyjne przeprowadzono w kwaśnych środowiskach siarczanowych o pH = 2 bez lub z jonami Cl-. Zastosowanie związków powierzchnio–czynnych ma za zadanie zwiększenie stopnia zdyspergowania silanu w roztworze modyfikującym, celem poprawy efektywności procesu osadzania.

EN

In this study, the protective properties of silane coatings based on VTMS vinyltrimethoxysilane and BRJI non-ionic surfactant were investigated. Ethanol was used as the solvent for organosilane and surfactant, while acetic acid was used to adjust the acidic environment (pH of the solutions between 3-4). The coatings were applied to samples of X20Cr13 stainless steel and 41Cr4 structural alloy steel by dip method in the sol-gel process using various surfactant concentrations. The obtained coatings were characterized in terms of corrosion resistance, adhesion to the steel substrate and thickness. Corrosion tests were carried out in acidic sulphate media with pH = 2 without or with Cl- ions. The purpose of the use of surfactants is to increase the degree of silane dispersion in the modifying solution in order to improve the efficiency of the deposition process.

17

Initial comparative studies of the anodic polarization of 304 austenitic steel in eutectic solvents containing propylene or ethylene glycol

Marczewski Marek, Frąckowiak Sandra, Winiarski Juliusz

Ochrona przed Korozją

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2022

|

nr 4

103--106

EN

This work presents preliminary comparative studies on the process of electrochemical polishing of austenitic 304 steel in two deep eutectic solvents (DES), based on polyols as hydrogen bond donors. The first is the choline chloride and ethylene glycol solvent, known before in the literature, and the second is the rarely discussed choline chloride and propylene glycol solvent. The analyzes showed that in the latter liquid it is possible to achieve similar results as in the first solvent, but without obtaining a full-fledged effect of electrochemical polishing. The process of anodic polarization in each range of current density for each liquid led to an increase in surface roughness and a simultaneous smoothing of the steel microstructure in the case of tested high current densities. For samples subjected to anodic polarization at medium and high current densities, a slight increase in corrosion resistance was observed compared to the chemically etched steel sample.

PL

W pracy zaprezentowano wstępne badania porównawcze nad procesem polerowania elektrochemicznego stali austenitycznej 304 w dwóch rozpuszczalnikach eutektycznych (deep eutectic solvents, DES) opartych na poliolach jako donorach wiązania wodorowego. Pierwszym z rozpuszczalników był znany w literaturze przedmiotu układ złożony z chlorku choliny i glikolu etylenowego, a drugim – rzadko omawiany układ złożony z chlorku choliny i glikolu propylenowego. Wykazano, że w wypadku ostatniej cieczy można osiągnąć podobne wyniki co w tej na bazie glikolu etylenowego, nie uzyskując jednak wyraźnego efektu polerowania elektrochemicznego. Proces polaryzacji anodowej w każdym zakresie gęstości prądu dla każdej cieczy doprowadził do zwiększenia się chropowatości powierzchni przy jednoczesnym wygładzeniu mikrostruktury stali w wypadku ustalonych wysokich gęstości prądu. Stwierdzono drobny wzrost odporności na korozję próbek poddanych polaryzacji anodowej przy średnich i wysokich gęstościach prądu w porównaniu z próbką stalową trawioną chemicznie.

18

Enhancement of corrosion resistance of stainless steel with Zn doped silane coatings

Owczarek Edyta

Ochrona przed Korozją

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2022

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nr 12

373--377

EN

Blank silane films are not able to provide long-term corrosion protection. As is known, dopants with corrosion inhibiting properties can be added to the silane sol-gel network in order to increase their corrosion resistance. The present work investigates the protective properties of air-aged films obtained from a solution of isobutyltriethoxysilane (IBTES) doped with 0.01 mol/l and 0.1 mol/l zinc nitrate Zn(NO3)2 ∙ 6H2O prepared on an X20Cr13 stainless steel substrate. The surface morphologies, adhesion to the substrate and the corrosion resistance of the obtained films in an 0.5 M Cl− solution were examined. The experimental results showed that IBTES films doped with 0.01 mol/l zinc nitrate deposited on the surface of stainless steel had better protective properties, while those doped with 0.1 mol/l of the inhibitor had worse protective properties against local corrosion compared to blank IBTES film.

PL

Powłoki silanowe nie są w stanie zapewnić długotrwałej ochrony przed korozją. Jak wiadomo, do sieci zol-żel silanu można dodawać domieszki o właściwościach hamujących korozję w celu zwiększenia ich odporności na korozję. W pracy zbadano właściwości ochronne starzonych w powietrzu powłok otrzymanych z roztworu izobutylo- trietoksysilanu (IBTES) domieszkowanych 0,01 mol/l i 0,1 mol/l azotanu cynku Zn(NO3)2 ∙ 6H2O wytworzonych na podłożu ze stali nie- rdzewnej X20Cr13. Zbadano morfologię powierzchni, przyczepność do podłoża oraz odporność korozyjną otrzymanych filmów w 0,5M roztworze Cl−. Badania eksperymentalne wykazały, że powłoki IBTES domieszkowane 0,01 mol/l azotanu cynku osadzone na powierzchni stali nierdzewnej miały lepsze właściwości ochronne przed korozją lokalną w porównaniu z powłoką IBTES, natomiast domieszkowane 0,1mol/l inhibitora – gorsze.

19

Effect of shot peening on corrosion resistance of additive manufactured 17-4PH steel

Świetlicki Aleksander, Walczak Mariusz, Szala Mirosław

Materials Science Poland

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2022

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Vol. 40, No. 3

135--151

EN

Components produced by additive manufacturing (AM) via direct metal laser sintering (DMLS) have typical as-fabricated surface defects. As a result, surface properties of AM products should be modified to increase their strength, anti-wear behavior, and at the same time ensure their high corrosion resistance. Surface modification via shot peening (SP) is considered suitable for AM of engineering devices made of 17-4PH (X5CrNiCuNb16-4) stainless steel. The objective of this study was to determine the effect of three types of peening media (CrNi steel shot, glass, and ceramic beads) on the corrosion resistance of specimens of DMLS 17-4PH stainless steel. Results demonstrated that SP caused steel microstructure refinement and induced both martensite (α) formation and retained austenite (γ) reduction. 17-4PH specimens peened showed the increase in surface hardness of 255, 281, and 260 HV0.2 for ceramic, glass, and steel, respectively. DMLS 17-4PH specimens modified by SP exhibited different surface morphology, hardness, and microstructure and thus, these properties affect corrosion performance. The results implied that steel shot peened with steel shot showed the highest resistance to corrosion processes (Icorr= 0.019μA/cm2), slightly worse with glass (Icorr= 0.227μA/cm2) and ceramics (Icorr= 0.660μA/cm2) peened. In the case of ceramic and glass beads, it was possible to confirm the presence of the above-mentioned particles in the surface layer after SP.

20

Preparation of composite steel with using of hot rolling

Kawulok Rostislav, Pasečný Daniel, Kawulok Petr, Rusz Stanislav, Opěla Petr, Schindler Ivo

Journal of Metallic Materials

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2022

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Vol. 74, no. 1

21--27

EN

The paper deals with the unconventional issue of composite steel preparation by hot rolling. Various production possibilities of multilayer composite from austenitic stainless steel AISI 304 and tool high carbon steel AISI D2 were investigated. Samples with 5, 15 and 45 layers were prepared. Optical microstructural analysis were subsequently performed on these samples with the focus on the details of joint and evaluation of the thicknesses of individual layers. In addition, hardness measurements were performed on the prepared samples, including its comparison with the individual steels used. It was confirmed that the hardness increased with increasing number of layers, however in this case, the difference between 15 and 45 layers was only 8 HBW. In addition it was found that the hardness of the prepared 45-layer packet without quenching was higher than that of the base (used) steels.

PL

Niniejszy artykuł poświęcono niekonwencjonalnemu zagadnieniu przygotowania kompozytu stalowego metodą walcowania na gorąco. Zbadano różne możliwości i metody wytwarzania wielowarstwowego kompozytu stalowego z austenitycznej stali nierdzewnej AISI 304 i wysokowęglowej stali narzędziowej AISI D2. W pracy opisano technologię przygotowania pakietów z tych stali złożonych z 5, 15 i 45 warstw. Następnie przeprowadzono na tych próbkach optyczne analizy mikrostrukturalne, skupiając się na szczegółach łączenia i ocenie grubości poszczególnych warstw. Ponadto na przygotowanych próbkach wykonano pomiary twardości, a wyniki porównano z poszczególnymi zastosowanymi stalami. Potwierdzono, że twardość wzrastała wraz ze wzrostem liczby warstw, jednak w przypadku różnicy między 15 a 45 warstwami różnica twardości to zaledwie 8 HBW. Ponadto stwierdzono, że twardość przygotowanego 45-warstwowego pakietu bez hartowania była wyższa niż (użytych) stali podstawowych.