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1

Comparison of the performance properties of commercially produced roller cone bit coatings

Koczkodaj Sylwia, Mizera Jarosław, Moszczynska Dorota, Zdunek Joanna, Plocinska Magdalena, Szpyrka Jacek, Burkot Marek, Szpak Mateusz

Materials Science Poland

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2023

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Vol. 41, No. 1

110-123

EN

This paper studies the material aspects of roller cone bits with milled teeth. The research concerns the properties of commercial product overlays provided by the company Glinik Drilling Tools. The analyzed coatings were produced according to the company’s procedures using two surfacing methods: gas welding and plasma transferred arc (PTA) welding. Metallographic observations and chemical composition analyses were carried out. The evaluation criteria in the context of the surfacing application were mechanical properties: hardness, impact strength, and abrasion resistance. The overlays produced by gas welding were characterized by lower hardness, impact strength, and abrasion resistance. The study showed that it differed from the deposit made by the PTA method in the matrix material and in the average size of the tungsten carbides. The dissolution of primary carbides and formation of secondary carbides such as Fe3C and Ni17W3 were found to occur in both surfacing types. This contributes to the increased brittleness of the matrix and reduced wear resistance of the materials.

2

Effect of annealing on the microstructure and properties of IN 625 specimens manufactured by selective laser melting

Sitek Ryszard, Ciftci Jakub, Moszczyńska Dorota, Maj Piotr, Ura-Bińczyk Ewa, Warzybok Piotr, Cieślik Iwona, Wiśniewski Paweł, Mizera Jarosław

Archives of Civil and Mechanical Engineering

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2022

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Vol. 22, no. 4

art. no. e207, 2022

EN

The study examines the effect of the annealing on the microstructure, tensile strength (small flat dog-bone specimen size with 5 mm dimension of measuring base) and corrosion resistance of IN 625 nickel superalloy specimens manufactured by means of selective laser melting method (SLM). The annealing of such specimens was carried out in a chamber furnace in a protective atmosphere of argon at a temperature of 1038 °C for 1 h. The cooling process was carried out in an atmosphere of air at ambient temperature. The microstructure of the IN 625 nickel superalloy after the 3D printing process and after the post-process heat treatment (HT) was examined by means of scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD). The results showed a uniform microstructure after the SLM process with element microsegregation. The cooling rate in the heat treatment was not sufficient which caused precipitation at the grain boundaries, most probably carbides and resulted in only a partial increase in ductility much lower than that of the material in initial state despite the high temperature applied during the annealing. The strength in the HT was on a level comparable to as-build state, 852 MPa and 891 MPa, respectively. Additional corrosion resistance tests were performed by the potentiodynamic method in a 3.5% NaCl solution at room temperature. HT increased the current density variation from ipass due to the formed precipitates. Our studies show that the size effect is an important factor when assessing the properties of IN 625 obtained using SLM. Despite similar microstructure, the structure defects play a more significant role which translates into lower mechanical properties than in normal sized specimens defined by the standard ASTM E8.

3

Analysis of direct metal laser sintering - DMLS and heat treatment influence on the Inconel 713C nickel alloy structure

Ciftci Jakub, Sitek Ryszard, Mizera Jarosław

Welding Technology Review

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2021

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R. 93, nr 3

49--56

EN

The group of nickel-based superalloys produced in the DMLS (Direct Metal Laser Sintering) process is limited to materials, which produced conventionally do not have properties to allow to use them for rotating components of aircraft engines. This work attempts to optimize the technological parameters of the DMLS process for the Inconel 713C nickel superalloy. A heat treatment was performed for selected samples to investigate the effect on the morphology of the Ni3Al phase. The microstructure analysis and hardness tests were carried out. The material after the DMLS process was characterized by the presence of much smaller dendrites than the cast material and exceeded its hardness. Additionally, for the tested variants of heat treatment, the material was characterized by smaller sizes of the Ni3Al phase by more than half. In order to ensure the stability of the microstructure, further optimization of the dedicated heat treatment after the DMLS process is required, as the standard heat treatment for Inconel 713C cast nickel superalloy does not fully recrystallize the material.

PL

Grupa nadstopów niklu wytwarzanych w procesie DMLS (ang. Direct Metal Laser Sintering) ogranicza się do materiałów, które wytwarzane konwencjonalnie nie posiadają właściwości, pozwalających zastosować je na elementy wirujące silników lotniczych. W pracy podjęto próbę optymalizacji parametrów technologicznych procesu DMLS dla nadstopu niklu Inconel 713C. Dla wybranych próbek przeprowadzono obróbkę cieplną w celu zbadania jej wpływu na morfologię fazy Ni3Al. Przeprowadzono analizę mikrostruktury oraz badania twardości. Materiał po procesie DMLS charakteryzował się obecnością znacznie mniejszych dendrytów niż materiał odlewany oraz przewyższał jego twardość. Dodatkowo dla zbadanych wariantów obróbki cieplnej materiał charakteryzował się mniejszymi rozmiarami fazy Ni3Al o ponad połowę. W celu zapewnienia stabilności mikrostruktury, wymagana jest dalsza optymalizacja obróbki cieplnej dedykowanej po procesie DMLS, ponieważ standardowa obróbka cieplna dla odlewanego nadstopu niklu Inconel 713C nie zapewnia pełnej rekrystalizacji materiału.

4

A critical review of corrosion rate calculations of Mg-Al-Li alloys using traditional mass loss measurements

Dobkowska Anna, Adamczyk-Cieślak Bogusława, Mizera Jarosław

Ochrona przed Korozją

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2020

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nr 2

38--41

EN

The corrosion rate (CR) calculations were performed for AZ31, AZ31-4Li, AZ31-7.5Li and AZ31-15Li Mg alloys after extrusion, and after extrusion with subsequent heat treatment. CR was obtained using three different mass loss (ML) measurements: i) traditional ML measurements where weighing before and after immersion was being implied, ii) by atomic absorption spectroscopy, where number of Mg2+ ions were calculated from the solution after immersion, and iii) by ML measurements in an artificial atmosphere. As results show, there are many differences in CR results obtained by these techniques. When CR is being calculated for multi-alloying materials, all possible anodic reactions which can take place during dissolution of immersed samples in the solution, should be considered.

PL

W pracy porównano szybkość korozji mierzoną trzema różnymi metodami dla stopów Mg-Li-Al. Szybkość korozji została obliczona w oparciu o i) grawimetryczne pomiary ubytku masy po zanurzeniu w roztworze, ii) analizę stężenia jonów Mg2+ w roztworze po zanurzenie próbek, iii) na podstawie pomiarów ubytku masy po ekspozycji próbek w komorze solnej. Na podstawie wykonanych pomiarów wskazano wady i zalety metod służących do oceny szybkości korozji stopów magnezu zawierających różne dodatki stopowe, w tym Al i Li. Wykazano, że dobór metody służącej do oceny szybkości korozji wieloskładnikowych stopów magnezu jest ściśle uzależniony od rodzaju i ilości reakcji anodowych zachodzących w trakcie ekspozycji materiału w środowisku korozyjnym.

5

Texture, residual stresses and mechanical properties analysis in the commercial 1.4462 duplex stainless steel subjected to hydrostatic extrusion

Zdunek Joanna, Maj Piotr, Kulczyk Mariusz, Mizera Jarosław

Archives of Civil and Mechanical Engineering

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2019

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Vol. 19, no. 2

525--534

EN

In the current research the hydrostatic extrusion (as one of the most common method of grain refinement) of the commercial 1.4462 duplex stainless steel was carried out using several reduction stages leading to a cumulative deformation strain ɛ = 1.4, and then ɛ = 3.8. The extrusion process has led to a change of microstructure and texture of the investigated material as was expected. Moreover, these changes were accompanied by improvements in mechanical properties measured by the nanohardness. The aim of this research was the characterization of the texture, residual stress and mechanical properties after subsequent stages of deformation.