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1

Size‑dependent constitutive model incorporating grain refinement and martensitic transformation

Liu Shengqiang, Li Wei, Shen Jinxia, Yang Xiaoming, Wang Baoyu, Liu Jinping

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 1

art. no. e38, 2023

EN

The deformation behaviour of materials at the micro-scale level is different from that at the macro-scale level due to the effect of grain size (GS). The mechanism of the influence on martensitic transformation by GS is still unclear, and there are relatively few studies on the relationship between grain refinement and martensitic transformation, most of which focus on the relationship between the initial GS of the material and martensitic transformation. Therefore, in this study, the interaction between grain refinement and martensitic transformation was investigated using a dislocation density-based multiscale constitutive model that incorporated dislocation sliding, strain-induced martensitic transformation (SIMT) related to grain size, and grain refinement. The proposed model evaluated the GS-dependent deformation behaviour of 316L stainless steel (SS). Subsequently, a genetic algorithm was used to determine the parameters of the established model, and the calculated results were compared with that of the experimental data to verify the accuracy of the model. The developed multiscale constitutive model was implemented in Abaqus user subroutine to further investigate the deformation mechanism and validate its accuracy. The results demonstrated that the GS had a significant effect on the SIMT, with the volume fraction of martensite increasing with a rise in the initial austenite GS. In addition, grain refinement affected SIMT and the growth rate of martensite content decreased with the grain refinement caused by deformation. The formation of martensite led to grain refinement, with the refined grains producing negative feedback on the SIMT, thus inhibiting the occurrence of martensitic transformation. This study revealed the microscopic deformation mechanism of 316L SS and provided a constitutive model for micro-forming.

2

The influence of plasma-sprayed coatings on surface properties and corrosion resistance of 316L stainless steel for possible implant application

Woźniak Anna, Staszuk Marcin, Reimann Łukasz, Bialas Oktawian, Brytan Zbigniew, Voinarovych Sergii, Kyslytsia Oleksandr, Kaliuzhnyi Sergii, Basiaga Marcin, Adamiak Marcin

Archives of Civil and Mechanical Engineering

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2021

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Vol. 21, no. 4

223--243

EN

Herein, we analyzed the morphology of atmospheric plasma-sprayed (APS) coating on medical 316L stainless steel and its influence on the physical and electrochemical properties of implant application. Five types of coatings were examined: hydroxyapatite (HAp), titanium (Ti), zirconium (Zr), Ti/HAp and Zr/HAp. The base properties of the coatings were analyzed via chemical and phase composition, surface topography, surface wettability and in particular the corrosion resistance in Ringer solution in immersed conditions and potentiodynamic test, and EIS analysis. APS coating of pure HAp on 316L stainless steel showed poor cohesive bonding to the substrate material, whereas the application of Ti and Zr interlayer prior to HAp deposition improved surface morphology and coating properties. The beneficial effect of Ti and Zr interlayer under HAp layer on binding was demonstrated. HAp containing coatings (HAp, Ti/HAp and Zr/HAp) show Ca/P ratio greater than 1.8, which may positively influence the differentiation of osteogenic cells and good adhesion to bones. Among the studied materials, the composite coatings with Zr or Zr/HAp showed favorable physicochemical properties and the highest corrosion resistance in Ringer solution.

3

Analiza możliwości poprawy struktury stereometrycznej powierzchni elementów wykonanych w technologii DMLS

Palczak A.

Problemy Nauk Stosowanych

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2016

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T. 5

85--92

PL

Wstęp i cel: W artykule dokonano analizy struktury stereometrycznej powierzchni i opisano podjęte próby poprawy jej właściwości dla elementów wykonanych metodą wytwarzania przyrostowego. Materiał i metody: Przebadano strukturę stereometryczną powierzchni elementów wytworzonych poprzez selektywne spiekanie wiązką lasera sproszkowanej stali 316L. Podjęto również próbę poprawy parametrów powierzchni wytworzonych elementów poprzez obróbkę skrawaniem, szlifowanie, nagniatanie ślizgowe i toczne. Wyniki: W wyniku przeprowadzonych badań uzyskano znaczą poprawę parametrów względem powierzchni surowych, uzyskanych bezpośrednio w procesie wytwarzania przyrostowego. Jednocześnie parametry powierzchni uzyskanych konwencjonalnymi metodami nie różniły się w znaczący sposób. Wniosek: Warstwa wierzchnia elementów wykonanych metodą laserowego spiekania proszków metali cechuje się znaczną chropowatością. Dodatkowa obróbka tak wytworzonych detali poprzez zastosowanie konwencjonalnych metod takich jak skrawanie lub nagniatanie pozwala w istotny sposób zmniejszyć chropowatość.

EN

Introduction and aim: The article shows the analyze of the surface texture and describes attempts to improve surface parameters for the components made with the use of additive manufacturing technology. Material and methods: The surface texture of the elements made of powdered 316L stainless steel with the use of direct metal laser sintering technology were studied. Also an attempt was made to improve the parameters of the surface of those elements by machining or grinding and after that by roller or slide burnishing. Results: During the studies a significant improvement was achieved, relative to the surface parameters obtained directly in the DMLS process. Surface parameters obtained by conventional methods did not differ significantly. Conclusion: The outer layer of elements made out of metal powders with the laser sintering technology is characterized by a high roughness. Additional mechanical treatment of these parts with the use of conventional methods like turning or grinding and than roller or slide burnishing can significantly reduce the roughness.

4

Wpływ temperatury spiekania na zużycie tribologiczne spieków 316L i 316L-HAp otrzymanych metodą iskrowego spiekania plazmowego

Mróz A., Garbiec D., Wiśniewski T., Gierzyńska-Dolna M., Magda J.

Tribologia

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2015

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nr 2

75--86

PL

Stosowanie bezniklowej stali austenitycznej 316L na implanty układu kostno-stawowego wiąże się z wieloma problemami eksploatacyjnymi. Jednym ze sposobów radzenia sobie z tymi ograniczeniami może być opracowanie nowych materiałów, w tym kompozytów, z zastosowaniem metalurgii proszków. W artykule przedstawiono wyniki badań tribologicznych spieków 316L i 316LHAp (hydroksyapatyt, HAp) otrzymanych metodą iskrowego spiekania plazmowego z zastosowaniem różnej temperatury spiekania. Dla stali 316L zwiększenie temperatury spiekania z 1000 do 1100°C skutkowało pogorszeniem odporności na zużycie. Niemniej w porównaniu z litą stalą 316L odporność na zużycie tych materiałów była znacząco większa. Dla kompozytów 316L-HAp zwiększenie temperatury spiekania skutkowało polepszeniem odporności na zużycie. Zużycie kompozytu spiekanego w niższej temperaturze było porównywalne ze zużyciem materiału referencyjnego.

EN

The use of 316L stainless steel in osteoarticular system implants is associated with many operational problems. One of the methods that deal with these restrictions may be the development of new materials, including composites, using powder metallurgy. This paper presents the results obtained during tribological tests of 316L and 316L-HAp sintered materials produced with the use of the spark plasma sintering method applying various sintering temperature. The increase of the sintering temperature from 1000 to 1100°C resulted in the deterioration of the wear resistance of 316L. However, compared to solid 316L, the wear resistance of these materials was several dozen times higher. The increase of the sintering temperature resulted in the improvement of the wear resistance of 316L-HAp. The wear resistance of the composites that had been sintered at lower temperatures was comparable to the reference material.

5

Oxide Formation In Metal Injection Molding Of 316L Stainless Steel

Jang J. M., Lee W., Ko S.-H., Han C., Choi H.

Archives of Metallurgy and Materials

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2015

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Vol. 60, iss. 2B

1281--1285

EN

The effects of sintering condition and powder size on the microstructure of MIMed parts were investigated using water-atomized 316L stainless steel powder. The 316L stainless steel feedstock was injected into micro mold with micro features of various shapes and dimensions. The green parts were debound and pre-sintered at 800°C in hydrogen atmosphere and then sintered at 1300°C and 1350°C in argon atmosphere of 5torr and 760torr, respectively. The oxide particles were formed and distributed homogeneously inside the sample except for the outermost region regardless of sintering condition and powder size. The width of layer without oxide particles are increased with decrease of sintering atmosphere pressure and powder size. The fine oxides act as the obstacle on grain growth and the high sintering temperature causes severe grain growth in micro features due to larger amount of heat gain than that in macro ones.

6

Double Step Sintering Behavior Of 316L Nanoparticle Dispersed Micro-Sphere Powder

Jeon B., Sohn S. H., Lee W., Han C., Kim Y. D., Choi H.

Archives of Metallurgy and Materials

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2015

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Vol. 60, iss. 2B

1155--1158

EN

316L stainless steel is a well-established engineering material and lots of components are fabricated by either ingot metallurgy or powder metallurgy. From the viewpoints of material properties and process versatility, powder metallurgy has been widely applied in industries. Generally, stainless steel powders are prepared by atomization processes and powder characteristics, compaction ability, and sinterability are quite different according to the powder preparation process. In the present study, a nanoparticle dispersed micro-sphere powder is synthesized by pulse wire explosion of 316L stainless steel wire in order to facilitate compaction ability and sintering ability. Nanoparticles which are deposited on the surface of micro-powder are advantageous for a rigid die compaction while spherical micro-powder is not to be compacted. Additionally, double step sintering behavior is observed for the powder in the dilatometry of cylindrical compact body. Earlier shrinkage peak comes from the sintering of nanoparticle and later one results from the micro-powder sintering. Microstructure as well as phase composition of the sintered body is investigated.

7

Application of X-ray CT method for discontinuity and porosity detection in 316L stainless steel parts produced with SLM technology

Ziółkowski G., Chlebus E., Szymczyk P., Kurzac J.

Archives of Civil and Mechanical Engineering

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2014

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Vol. 14, no. 4

608--614

EN

Industrial tomography (XCT) is a nondestructive test method that provides information about spatial distribution of X-ray absorption in the analyzed structures. The aim of this paper was to examine the possibility and accuracy of application of XCT method for discontinuity and porosity detection in parts made of 316L stainless steel powder produced by Selective Laser Melting technology. Analysis conducted on three produced test samples showed that the application of XCT as a method of quality control of specimens produced with an additive manufacturing technology offers a wide range of possibilities to detect porosity within materials. Parameters such as the amount of porosity, pore size and pore shape are presented. Accuracy of XCT method strongly depends on the size of the samples analyzed, but the possibility of obtaining information in 3D nondestructively shows considerable advantages of XCT method over traditional metallographic cross-sectional analysis.

8

Inhibition of corrosion of AISI 316L steel in concentrated acetic acid containing NaCl additions

Bala H., Adamczyk L., Owczarek E., Gruetzner T., Seyfang B. C.

Ochrona przed Korozją

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2012

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nr 11

460-463

EN

The effect of Akolidine-10 additions (0.001-0.1%) into deaerated, 5M acetic acid solution on corrosion behaviour of 316L (X2CrNiMo 18-14-3) stainless steel has been investigated in the absence and in presence of NaCl addition. It can be postulated that Akolidine-10 decreases the hydrogen activity on the steel corroding surface. Additions of Akolidine-10 into the test solution is particularly advantageous in passive region because it protects steel surface against local corrosion attack.

PL

Badano wpływ dodatków Akolidyny-10 (0,001-0,1%) do odpowietrzonego roztworu 5M kwasu octowego na zachowanie korozyjne stali kwasoodpornej 316L (X2CrNiMo 18-14-3) w nieobecności - i w obecności dodatków NaCl. Uzyskane wyniki pozwalają przyjąć, że Akolidyna-10 zmniejsza aktywność wodoru na korodującej powierzchni stali. Dodatki Akolidyny-10 do roztworu roboczego są szczególnie korzystne w warunkach pasywacji stali, gdyż chronią jej powierzchnię przed lokalnym atakiem korozyjnym.

9

Characterizations and evaluations on the bonding quality of molybdenum disilicides

Lu L. W., Qin W. G.

Archives of Metallurgy and Materials

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2011

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Vol. 56, iss. 4

1271-1271

EN

In this study, we proposed a new method using the spark plasma sintering technique to bond ceramics to alloys. MoSi2 and 316L stainless steel were chosen as sample materials and can be welded well with graded interlayers. We found that dense uniformed bondings were achieved because of the comparable coefficient of thermal expansion of the interlayers. Furthermore, such a compatibility between the graded interlayers prevented MoSi2 with low toughness from the occurrence of microcracks resulted from the residual stresses formed during cooling of the bondings.

PL

W pracy zaproponowano nowa metodę łączenia ceramiki i stopów metodą spiekania iskrowo plazmowego SPS (spark plasma sintering). MoSi2 i stal nierdzewna 316L zostały wybrane jako przykładowe materiały i moga byc łaczone poprzez gradientowe warstwy pośrednie. Okazało się, że zwarte, jednorodne połączenia zostały uzyskane dzieki porównywalnemu współczynnikowi rozszerzalności cieplnej warstw pośrednich. Ponadto, tego rodzaju zgodnosc pomiedzy warstwami pośrednimi zapobiegła wystapieniu mikropęknięć w MoSi2, który jest materiałem o niskiej twardości, będacych wynikiem naprezen powstałych podczas chłodzenia połączeń.

10

Study of hydroxyapatite behaviour during sintering of 316L steel

Szewczyk-Nykiel A., Nykiel M.

Archives of Foundry Engineering

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2010

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Vol. 10, iss. 3 spec.

235--240

EN

316L stainless steel – hydroxyapatite composite biomaterials with different hydroxyapatite weight fraction in the composite were investigated. Hydroxyapatite (HAp – Ca10(PO4)6(OH)2) is well known biomaterial. HAp reveals excellent chemical and biological affinity with bony tissues. On the other hand hydroxyapatite shows low mechanical properties. The combination of very good biocompatibility of hydroxyapatite and high mechanical properties of stainless steel seems to be a good solution. In presented research natural origin hydroxyapatite and 316L austenitic stainless steel were used. In this work, metal-ceramics composites were fabricated by the powder metallurgy technology (involving pressing and sintering process). Sintering was carried out at 1250oC in hydrogen atmosphere. The density, porosity and hardness were investigated. Metallographic microscope and SEM were carried out in order to investigate the microstructure. The horizontal NETZSCH DIL 402E dilatometer was used to evaluate the dimensional changes and phenomena occurring during sintering. The research displayed that physical properties of sintered 316L-HAp composites decrease with increase of hydroxyapatite content. Microstructure of investigated composites consists of austenitic and probably inclusions of hydroxyapatite and heterogeneous eutectic occurring on the grain boundaries. It was shown that amount of hydroxyapatite in the powder mixtures influence the dimensional changes occurring during sintering.