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1

Evaluation of Microstructure and Tribological Properties of GX120Mn13 and GX120MnCr18-2 Cast Steels

Kalandyk B., Zapała R., Kasińska J., Madej M.

Archives of Foundry Engineering

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2021

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Vol. 21, iss. 4

77--81

EN

The results of microstructure examinations and hardness measurements carried out on two selected grades of high-manganese cast steel with an austenitic matrix, i.e. GX120Mn13 and GX120MnCr18-2, are presented. The examinations of the cast steel microstructure have revealed that the matrix of the GX120MnCr18-2 cast steel contains the precipitates of complex carbides enriched in Cr and Mn with two different morphologies. The presence of these precipitates leads to an increase in hardness by approx. 30 HB compared to the GX120Mn13 cast steel. Samples cut out from the tested materials were loaded (10 strokes) with an energy of 53 J, and then a ball-on-disc tribological test was performed. The test was carried out in reciprocating motion under technically dry friction conditions. While analyzing the obtained results of the microstructure, hardness, and abrasion tests, it was found that the presence of the hard carbide precipitates in the plastic matrix of the tested GX120MnCr18-2 cast steel promoted an increase in hardness, but also led to chipping of these particles from the alloy matrix, thus contributing to micro-cutting during friction.

2

The Effect of CaSiAl Modification on the Non-metallic Inclusions and Mechanical Properties of Low-carbon Microalloyed Cast Steel

Kalandyk B., Zapała R., Sobula S., Tęcza G.

Archives of Foundry Engineering

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2019

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iss. 1

47--52

EN

The effect of CaSiAl modification (43-49% Ca, 43-48% Si, 2% Al) on the non-metallic inclusions and mechanical properties of cast low-carbon steel is discussed. Tests were carried out on the cast steel with 0.2% C and micro-additives of V and Nb, used mainly for heavy steel castings (e.g. slag ladles). The modifier in an amount of 1.5 and 3 kg / Mg was introduced to the liquid steel before tapping the metal into a ladle. Test ingots of Y type and a weight of 10 kg were cast and then subjected to a normalizing heat treatment. Using light microscopy and scanning electron microscopy, qualitative and quantitative evaluation of the non-metallic inclusions present in as-cast samples was carried out. Additionally, tests of mechanical strength and impact strength were performed on cast steel with and without the different content of modifier. It was found that increasing the modifier addition affected impact strength but had no significant effect on tensile strength and yield strength. The material with high impact strength had the smallest area fraction of non-metallic inclusions in the microstructure (0.20%). The introduction of modifiers changed the morphology of non-metallic inclusions from dendritic to regular and nodular shapes.

3

Microstructure and Properties of 17Cr-0.8C Cast Steel

Kalandyk B., Zapała R., Pałka P., Wróbel M.

Archives of Metallurgy and Materials

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2018

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Vol. 63, iss. 1

113-117

EN

The results of studies of the microstructure and properties of cast high alloy steels containing 17% Cr and 0.8% C subjected to different variants of heat treatment are presented. For phase identification, the light microscopy and scanning electron microscopy as well as the X-ray diffraction analysis were used. The conducted studies revealed the presence of carbides in the microstructure, mainly of the M23C6 carbide, detected after both quenching and tempering at 200 and 600°C. The use of low and high tempering significantly reduced the test alloy hardness from 657.3 HV30 to 403.7 HV30. At the same time, hardness was observed to have an impact on the values of abrasion in the conducted Miller slurry test. Higher material hardness leads to lower wear expressed by mass loss.

4

Effect of Silicon Addition on the Microstructure of Cast 24Cr-5Ni-2.5Mo-xSi Duplex Steel

Kalandyk B., Zapała R., Witkowska M., Kowalska J.

Archives of Foundry Engineering

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2018

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Vol. 18, iss. 1

186--190

EN

Characteristics of the microstructure of corrosion-resistant cast 24Cr-5Ni-2.5Mo duplex steel after introduction of 0.98, 1.67 and 4.3% Si were described. Based on the test results it has been found that silicon addition introduced to the corrosion-resistant cast two-phase duplex steel significantly reduces austenite content in the alloy matrix. Increasing silicon content in the test alloy to 4.3% has resulted, in addition to the elimination of austenite, also in the precipitation of Si-containing intermetallic phases at the grain boundaries and inside the grains. The precipitates were characterized by varying content of Cr and Mo, indicating the presence in the structure of more than one type of the brittle phase characteristic for this group of materials. The simulation using Thermo-Calc software has confirmed the presence of ferrite in all tested alloys. In the material containing 4.3% Si, the Cr and Si enriched precipitates, such as G phase and Cr3Si were additionally observed to occur.

5

Changes in Impact Strength and Abrasive Wear Resistance of Cast High Manganese Steel Due to the Formation of Primary Titanium Carbides

Tęcza G., Zapała R.

Archives of Foundry Engineering

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2018

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Vol. 18, iss. 1

119--122

EN

Cast high-manganese Hadfield steel is commonly used for machine components operating under dynamic load conditions. Their high fracture toughness and abrasive wear resistance is the result of an austenitic structure, which - while being ductile - at the same time tends to surface harden under the effect of cold work. Absence of dynamic loads (e.g. in the case of sand abrasion) causes rapid and premature wear of parts. In order to improve the abrasive wear resistance of cast high-manganese steel for operation under the conditions free from dynamic loads, primary titanium carbides are produced in this cast steel during melting process to obtain in castings, after melt solidification, the microstructure consisting of an austenitic matrix and primary carbides uniformly distributed therein. After heat treatment, the microhardness of the austenitic matrix of such cast steel is up to 580 μHV20 and the resulting carbides may reach even 4000 μHV20. The impact strength of this cast steel varies from 57 to 129 and it decreases with titanium content. Compared to common cast Hadfield steel, the abrasive wear resistance determined in Miller test is at least twice as high for the 0.4% Ti alloy and continues growing with titanium content.

6

Influence of Internal Scrap on Mechanical Properties of Selected Cobalt Alloys

Dęsoł B., Zapała R., Pałka P.

Journal of Casting & Materials Engineering

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2017

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Vol. 1, no. 3

59--63

EN

This paper presents the results of mechanical tests carried out on two different commercially available cobalt alloys applied in dental prosthetics for the production of frame dentures. The test samples were obtained by the method of investment casting using as a charge pure primary materials and pure primary materials mixed with various additions of process scrap (25, 50, and 75%). The tests showed that the alloys could not reach the mechanical properties reported by the manufacturer in either case. In the case of the alloy without the addition of tantalum, the general conclusion was that both the plastic and strength properties decreased with increasing amounts of the introduced process scrap. The mechanical properties (mainly elongation) of the alloy containing Ta reached the highest values in the samples containing 75% of the process scrap. Examinations of fractures carried out by SEM have revealed their varied character – ductile or transcrystalline. All of the samples tested showed the presence of dendrites and solidification areas, with shrinkage porosity occurring in the internal sample zones.

7

The Effect of Si and Mn on Microstructure and Selected Properties of Cr-Ni Stainless Steels

Kalandyk B., Zapała R., Starowicz M.

Archives of Foundry Engineering

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2017

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Vol. 17, iss. 1

192--196

EN

Cast stainless steel of the Cr-Ni duplex type is used, among others, for the cast parts of pumps and valves handling various chemically aggressive media. Therefore, the main problem discussed in this article is the problem of abrasion wear resistance in a mixture of SiC and water and resistance to electrochemical corrosion in a 3% NaCl- H2O solution of selected cast steel grades, i.e. typical duplex cast steel, high silicon and manganese duplex cast steel, and Cr-Ni austenitic cast steel (type AISI 316L). The study shows that the best abrasion wear resistance comparable to Ni-Hart cast iron was obtained in the cast duplex steel, where Ni was partially replaced with Mn and N. This cast steel was also characterized by the highest hardness and matrix microhardness among all the tested cast steel grades. The best resistance to electrochemical corrosion in 3% NaCl- H2O solution showed the cast duplex steel with high content of Cr, Mo and N. The addition of Ni plays rather insignificant role in the improvement of corrosion resistance of the materials tested.

8

Effect of Tempering Temperature on the Mechanical Properties of Cast L35HM Steel

Zapała R., Kalandyk B., Wawro P.

Archives of Foundry Engineering

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2017

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Vol. 17, iss. 2

151--156

EN

A possibility to control the strength, hardness and ductility of the L35HM low-alloy structural cast steel by the applied tempering temperature is discussed in the paper. Tests were carried out on samples taken from the two randomly selected industrial melts. Heat treatment of the cast samples included quenching at 900°C, cooling in an aqueous solution of polymer, and tempering at 600 and 650°C. The obtained results showed that the difference in the tempering temperature equal to 50°C can cause the difference of 121 MPa in the values of UTS and of 153 MPa in the values of 0.2%YS. For both melts tempered at 600 °C, the average values of UTS and 0.2%YS were equal to 995 MPa and 933 MPa, respectively. The values of EL and RA did not show any significant differences. Attention was drawn to large differences in strength and hardness observed between the melts tempered at 600 and 650°C. Despite differences in the mechanical properties of the examined cast steel, the obtained results were superior to those specified by the standard.

9

Microstructure Examinations in Corners of the Low-Carbon Steel Slabs from Continuos Caster Machine

Kwinta G., Kara S., Kalandyk B., Zapała R., Pałka P.

Archives of Metallurgy and Materials

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2016

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Vol. 61, iss. 4

2051--2056

EN

The exposed selvedge layers in slabs cast by the continuous process should be free from surface defects, which in most cases appear in the form of cracks on the casting surface and run to its interior. In addition to the parameters of the casting process, the occurrence of such defects depends on the chemical composition of cast steel, on the segregation of surface active elements and formation of the precipitates of carbides, nitrides and other phases. Due to the frequent occurrence of defects in corners of the slabs, non-destructive testing was performed on the mechanically cleaned surfaces of slabs. The test material was low-carbon API(American Petroleum Institute API 5L standard) steel micro alloyed with Nb and Ti designed for the production of pipes to handle gas, oil and other liquid and gaseous fuels. Despite the use of different methods of inspection, i.e. ultrasonic, magnetic particle and penetrant, cracks were not traced in the examined material. Then, from the corners of the examined slabs, specimens were cut out for metallographic examinations. The main purpose of these examinations was to disclose the presence of possible cracks and micro cracks on the surfaces transversal and longitudinal to the direction of casting. At the same time, studies were conducted to establish the number and morphology of non-metallic inclusions in selvedge layers of the slab corners and axis. Additionally, hardness of the slabs was measured. The conducted studies revealed only some minor differences in the slab hardness along its axis (130 ÷ 135 HB) and in selvedge layers (120 ÷ 123 HB).

10

High-temperature oxidation of cast steel in water vapour

Zapała R., Pach S., Górny M., Homa M., Siewiorek A.

Prace Instytutu Odlewnictwa

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2015

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T. 55, nr 3

61--70

EN

The article presents the results of studies of the oxidation process conducted at 900°C for 12 hours in an atmosphere of water vapour on cast heat-resistant steel with a diversified structure (ferritic-austenitic, austenitic, and austenitic with carbides). Based on the studies of oxidation kinetics, it was found that samples were oxidized in approximation with the rules of linear law. Depending on the chemical composition and structure of tested alloys, the scale formed on the alloy surface had different properties. In the tested material characterised by a ferritic-austenitic structure, the tendency of the scale to detach from the surface of the metallic substrate was observed. It was probably due to different coefficients of the thermal expansion of austenite and ferrite.

PL

Praca prezentuje wyniki badań utleniania w atmosferze pary wodnej staliwa żaroodpornego o różnej strukturze (ferrytyczno-austenitycznej, austenitycznej i austenitycznej z węglikami) w temperaturze 900°C w ciągu 12 godzin. Na podstawie badań kinetyki utleniania stwierdzono, że badane próbki utleniały się w przybliżeniu zgodnie z prawem liniowym. W zależności od składu chemicznego i struktury badanych stopów obserwowano odmienne właściwości powstałych zgorzelin. W przypadku materiału o strukturze ferrytyczno-austenitycznej stwierdzono odpadanie zgorzeliny od powierzchni rdzenia metalicznego związane prawdopodobnie z różnym współczynnikiem rozszerzalności cieplnej austenitu i ferrytu.

11

Microstructure and Mechanical Properties of High-Alloyed 23Cr-5Mn-2Ni-3Mo Cast Steel

Kalandyk B., Zapała R., Kasińska J., Wróbel M., Balicki M.

Archives of Metallurgy and Materials

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2015

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Vol. 60, iss. 4

2529--2534

EN

The article presents the microstructure and mechanical properties of cast duplex stainless steel type 23Cr-5Mn-2Ni-3Mo. It has been shown that the structure of the tested cast steel is composed of ferrite enriched in Cr, Mo and Si, and austenite enriched in Mn and Ni. In the initial state, at the interface, precipitates rich in Cr and Mo were present. A high carbon content (0.08%C) in this cast steel indicates that probably those were complex carbides of the M23C6 type and/or σ phase. Studies have proved that the solution annealing conducted at 1060°C was not sufficient for their full dissolution, while at the solutioning temperature of 1150°C, the structure of the tested material was composed of ferrite and austenite. Partial replacement of Ni by two other austenite-forming elements, which are Mn and N, has ensured obtaining mechanical properties comparable to cast duplex 24Cr-5Ni-3Mo steel of the second generation. Basing on the results of static tensile test, a twice higher yield strength was proved to be obtained, compared to the cast austenitic 18Cr-9Ni and 19Cr-11Ni-2Mo steel commonly used in the foundry industry. In addition to the high yield strength (YS = 547 ÷ 572 MPa), the tested cast steel was characterized by the following mechanical properties: UTS = 731 ÷ 750 MPa, EL = 21 ÷ 29.5%, R.A. = 43 ÷ 52%, hardness 256 ÷ 266 HB. Fractures formed in mechanical tests showed ductile-brittle character.

PL

W artykule przedstawiono mikrostrukturę i właściwości mechaniczne, kwasoodpornego staliwa ferrytyczno - austenitycznego 23Cr-5Mn-2Ni-3Mo typu duplex. Wykazano, że struktura badanego staliwa składa się z ferrytu δ wzbogaconego w C r, Mo i S i oraz austenitu wzbogaconego w Mn i Ni. W stanie wyjściowym na granicy międzyfazowej występują wydzielenia wzbogacone w C r i Mo. Wysoka zawartość C (0.08%) w tym staliwie wskazuje, że prawdopodobnie są to złożone węgliki M23C6 i/lub faza σ. Wykazano, że temperatura przesycania 1060°C nie jest wystarczająca do ich całkowitego rozpuszczenia. Natomiast w temperaturze przesycania 1150°C struktura badanego materiału składa się z ferrytu i austenitu. Częściowe zastąpienie Ni przez dwa inne pierwiastki austenitotwórcze jakimi są Mn i N zapewniło uzyskanie porównywalnych właściwości mechanicznych do staliwa duplex 24Cr-5Ni-3Mo drugiej generacji. Na podstawie przeprowadzonej statycznej próby rozciągania wykazano dwukrotnie wyższą granicę plastyczności w porównaniu do często stosowanego w przemyśle odlewniczym austenitycznego staliwa 18Cr-9Ni i 19Cr-11Ni-2Mo. Poza wysoką granicą plastyczności (Rp0,2 = 547 ÷ 572 MPa), badane staliwo charakteryzowało się następującymi właściwościami mechanicznymi: Rm = 731 ÷ 750 MPa, As = 21 ÷ 29,5%, Z = 43 ÷ 52%, HB = 256 ÷ 266. Przełomy po badaniach wytrzymałościowych wykazywały charakter ciagliwo-kruchy.

12

Odporność korozyjna dwufazowego staliwa 24Cr-5Mn-2Ni-3Mo

Kalandyk B., Starowicz M., Zapała R.

Archives of Foundry Engineering

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2015

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Vol. 15, iss. 4 spec.

53--56

PL

Przedmiotem badań było porównanie odporności na korozję elektrochemiczną dwóch gatunków kwasoodpornego staliwa ferrytyczno-austenitycznego (duplex): klasycznego zawierającego 24Cr-5Ni-2,5Mo-2,6Cu z nowym gatunkiem staliwa zawierającym 24Cr-5Mn-2Ni-3Mo, w którym Ni częściowo został zastąpiony przez Mn i N. Zawartość pierwiastków austenitotwórczych (Ni, Mn i N) została tak dobrana, aby udział ferrytu δ w staliwie wynosił 45÷50%. Na podstawie przeprowadzonych badań korozyjnych stwierdzono, że oba materiały ulegają samorzutnej pasywacji w 3% roztworze NaCl. Staliwo z podwyższoną zawartością Mn i N posiada znacznie wyższą wartość potencjału bezprądowego (Eo = -0,7 V), niż klasyczne staliwo duplex (Eo = -0,95V) oraz wykazuje zasadnicze różnice w gęstości prądu anodowego. Jest ono również bardziej odporne na korozję lokalną. Analiza mikrostrukturalna produktów korozji wskazuje na obecność nielicznych wżerów korozyjnych powstających głównie na wtrąceniach niemetalicznych.

EN

The aim of the studies was to compare the electrochemical corrosion resistance of the two grades of acid-resistant cast austenitic-ferritic (duplex) steel, i.e. the conventional grade containing 24Cr-5Ni-2.5Mo-2.6Cu and a cast steel grade containing 24Cr-5Mn-2Ni-3Mo, where Ni was partially replaced by a higher content of Mn and N. The content of austenite-forming elements (Ni, Mn and N) has been chosen in such a way as to keep the δ ferrite fraction in the cast steel at a level of 45 ÷ 50%. Based on the corrosion test results, it was found that both materials undergo a spontaneous passivation in the 3% NaCl solution. The cast steel with increased content of Mn and N has a much higher value of the electro less potential (Eo = -0.7 V) than the conventional cast duplex steel (Eo = -0,95V), and shows substantial differences in the anodic current density. It is also more resistant to local corrosion. Microstructural analysis of corrosion products indicates the presence of very few corrosion pits formed mainly on the non-metallic inclusions.

13

Cast High-Manganese Steel – the Effect of Microstructure on Abrasive Wear Behaviour in Miller Test

Kalandyk B., Tęcza G., Zapała R., Sobula S.

Archives of Foundry Engineering

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2015

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Vol. 15, iss. 2

35--38

EN

The results of the modification of austenitic matrix in cast high-manganese steel containing 11÷19% Mn with additions of Cr, Ni and Ti were discussed. The introduction of carbide-forming alloying elements to this cast steel leads to the formation in matrix of stable complex carbide phases, which effectively increase the abrasive wear resistance in a mixture of SiC and water. The starting material used in tests was a cast Hadfield steel containing 11% Mn and 1.34% C. The results presented in the article show significant improvement in abrasive wear resistance and hardness owing to the structure modification with additions of Cr and Ti.

14

Impact Strength of Austenitic and Ferritic-Austenitic Cr-Ni Stainless Cast Steel in -40 and +20°C Temperature

Kalandyk B., Zapała R., Boroń Ł., Solecka M.

Archives of Metallurgy and Materials

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2014

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Vol. 59, iss. 3

1103--1106

EN

Studies described in this paper relate to common grades of cast corrosion resistant Cr-Ni steel with different matrix. The test materials were subjected to heat treatment, which consisted in the solution annealing at 1060°C followed by cooling in water. The conducted investigations, besides the microstructural characteristics of selected cast steel grades, included the evaluation of hardness, toughness (at a temperature of -40 and +20°C) and type of fracture obtained after breaking the specimens on a Charpy impact testing machine. Based on the results of the measured volume fraction of ferrite, it has been found that the content of this phase in cast austenitic steel is 1.9%, while in the two-phase ferritic-austenitic grades it ranges from 50 to 58%. It has been demonstrated that within the scope of conducted studies, the cast steel of an austenitic structure is characterised by higher impact strength than the two-phase ferritic-austenitic (F-A) grade. The changing appearance of the fractures of the specimens reflected the impact strength values obtained in the tested materials. Fractures of the cast austenitic Cr-Ni steel obtained in these studies were of a ductile character, while fractures of the cast ferritic-austenitic grade were mostly of a mixed character with the predominance of brittle phase and well visible cleavage planes.

PL

Zaprezentowane w artykule badania dotyczą popularnych gatunków kwasoodpornego staliwa Cr-Ni o różnej osnowie. Zastosowane do badań materiały poddano obróbce cieplnej (przesycanie w temperaturze 1060°C i chłodzenie w wodzie). Przeprowadzone badania oprócz charakterystyki mikrostruktury wybranych gatunków staliwa obejmowały ocenę twardości, udarności (w temperaturze -40 i +20°C) oraz charakteru przełomów uzyskanych w wyniku złamania próbek na młocie Charpie'go. Na podstawie uzyskanych wyników udziału objętościowego ferrytu stwierdzono, że w staliwie austenitycznym występuje 1.9% tej fazy, natomiast w dwóch staliwach ferrytyczno-austenitycznych (F-A) udział ferrytu mieścił się w przedziale 50÷58%. Wykazano, że staliwo o strukturze austenitycznej charakteryzuje się wyższą udarnością w porównaniu do dwufazowego staliwa ferrytyczno-austenitycznego (F-A). Zmiany jakie zaszły w charakterze przełomów próbek były odzwierciedleniem uzyskanych wyników udarności badanych materiałów. W zakresie przeprowadzonych badań przełomy austenitycznego staliwa Cr-Ni wykazują charakter ciągliwo-kruchy, a przełomy staliwa F-A są przeważnie przełomami o charakterze mieszanym z przewagą przełomu kruchego z widocznymi płaszczyznami łupliwości.

15

Structure and properties of the centrifugally cast high-alloyed (25Cr35NiNbTi) steel after long-time operation in steam reforming

Mikułowski B., Zapała R., Głownia J., Wilk P.

Archives of Metallurgy and Materials

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2013

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Vol. 58, iss. 3

785--790

EN

The paper presents the influence of performance conditions of high-alloyed nickel-chromium cast steel intended for use in steam reforming plants on the morphology and number of phases present in centrifugally cast tubes. Structure identification was done by the methods of light and scanning microscopy. It was found that the main components of the tested cast steel microstructures are carbides of, among others, chromium, iron, and niobium. The structure has also been reported to contain the sigma phase. Additionally, at three test temperatures (20, 820 and 945°), the mechanical properties of the cast steel were determined after years of operation under industrial conditions. The tested material was characterised by low, compared with standard requirements, mechanical properties. A relationship between the content of phases (primary and secondary carbides), measured by the methods of quantitative metallography, and the yield strength of the tested material was determined. The yield strength determined at room temperature, and at 820° and 945° assumed higher values in samples characterised by a relatively large volume content of phases.

PL

W pracy przedstawiono wpływ warunków eksploatacji wysokostopowego staliwa niklowo-chromowego przeznaczonego do pracy w instalacjach reformingu parowego na morfologię oraz ilość faz występujących w materiale rur odlewanych odśrodkowo. Do identyfikacji struktury wykorzystano metody mikroskopii świetlnej i skaningowej. Ponadto w trzech temperaturach badań (20, 820 i 945°) określono własności mechaniczne staliwa po eksploatacji w warunkach przemysłowych. Wyznaczono związek pomiędzy ilością faz (węglików pierwotnych i wtórnych), określona przy wykorzystaniu metody metalografii ilościowej, a umowną granicą plastyczności badanego materiału.

16

Microstructure and corrosion resistance characteristics of Cr-Co-Mo alloys designed for prosthetic materials

Augustyn-Pieniążek J., Łukaszczyk A., Zapała R.

Archives of Metallurgy and Materials

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2013

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Vol. 58, iss. 4

1281--1285

EN

The work presents the results of microscopic tests of two alloys: Co-Cr-Mo and Co-Cr-W-Mo, together with a quantitative local analysis of the chemical composition, with the use of an electron microprobe X-ray analyzer EDS. Corrosion resistance tests were also performed on the alloys, in the artificial saliva environment. The microstructure of the examined alloys was of the dendrite type. An eutectic consisting of alloy carbides and a cobalt austenite was observed in the interdendritic spaces. The dendritic matrix was a solid solution of chromium, molybdenum and carbon in cobalt (γCo), and the precipitates present in the interdendritic spaces were rich with Cr and Mo - in the case of Co-Cr-Mo - and with W and Mo - in the case of Co-Cr-W-Mo. The analyzed materials exhibited a similar progress of polarization curves. The obtained currentless potential values and the wide passivation area of those alloys made it possible to conclude their high corrosion resistance in the examined environment.

PL

W pracy przedstawiono wyniki badań mikroskopowych dwóch stopów: Co-Cr-Mo i Co-Cr-W-Mo wraz z ilościową analizą punktową składu chemicznego przy wykorzystaniu mikroanalizatora rentgenowskiego EDS. W ramach pracy wykonano również badania odporności korozyjnej stopów w środowisku sztucznej śliny. Mikrostruktura badanych stopów miała budowę dendrytyczną. W przestrzeniach międzydendrytycznych występowała eutektyka składająca się z węglików stopowych i austenitu kobaltowego. Osnowę dendrytyczną stanowił roztwór stały chromu, molibdenu i węgla w kobalcie (γCo), zaś wydzielenia występujące w obszarach międzydendrytycznych były bogate w Cr i Mo - w przypadku stopu Co-Cr-Mo oraz W i Mo - w przypadku stopu Co-Cr-W-Mo. Analizowane materiały wykazywały zbliżone przebiegi krzywych polaryzacji. Z otrzymanych wartości potencjału bezprądowego oraz na podstawie szerokiego obszaru pasywacji tych stopów można wnioskować o ich wysokiej odporności korozyjnej w badanym środowisku.

17

Effect of high-manganese cast steel strain hardening on the abrasion wear resistance in a mixture of SiC and water

Kalandyk B., Zapała R.

Archives of Foundry Engineering

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2013

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Vol. 13, iss. 4

63--66

EN

The study attempts to determine the impact of the high-manganese cast steel strain hardening on its abrasion wear resistance in a mixture of SiC and water prepared in accordance with ASTM G75. For tests, the high-manganese cast steel containing 10.7, 17.9 and 20.02% Mn was selected. The results of microstructure examinations and abrasion wear resistance tests carried out on the material in non-hardened condition and after strain hardening with a force of 539.55kN were disclosed. Additionally, the surface of samples after a 16-hour cycle of abrasion tests was examined. Moreover, based on the obtained results, the effect of different contents of Mn in cast steel was studied, mainly in terms of its impact on the abrasion wear resistance. The results obtained on the tested materials were compared with the results obtained on the low-alloyed abrasion wear-resistant cast steel L35GSM.

18

Charakterystyka warstw tlenkowych powstałych na staliwie Cr-Ni modyfikowanym Ce podczas wysokotemperaturowego utleniania

Zapała R., Augustyn-Pieniążek J., Kalandyk B.

Inżynieria Materiałowa

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2012

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Vol. 33, nr 1

37--41

PL

W pracy badano wpływ Ce w staliwie chromowo-niklowym na korozję wysokotemperaturową. W artykule przedstawiono wyniki badań kinetyki utleniania stopu w temperaturze: 820, 930 i 1000°C oraz charakterystykę morfologii powierzchni zgorzeliny utworzonej na staliwie Cr-Ni. Badania warstwy produktów korozji powstałych podczas izotermicznego utleniania obejmowały obserwacje mikroskopowe (SEM), mikroanalizę rentgenowską (EDS) oraz pomiary rentgenograficzne za pomocą rentgenowskiej dyfrakcyjnej analizy fazowej z zastosowaniem dyfrakcji w geometrii Bragg-Brentano. Stwierdzono, że materiał dla wszystkich wartości temperatury badań utleniał się w przybliżeniu zgodnie z prawem parabolicznym. Powstała zgorzelina była zwarta i ciągła dla niższej temperatury utleniania. W badanych zgorzelinach za pomocą dyfrakcyjnej analizy fazowej zidentyfikowano następujące fazy: Cr2O3, MnCr2O4, (Cr, Fe)2O3, SiO2 i CrNbO4.

EN

The effect of Ce on the behaviour of cast chromium-nickel steel subjected to high temperature corrosion was investigated. The work also includes studies of the kinetics of oxidation of the alloy at temperatures of 820, 930 and 1000°C and the characteristics of the surface morphology of the scale formed on the Cr-Ni cast steel. Examinations of the layer of corrosion products formed during isothermal oxidation included microscopic observations (SEM), X-ray microanalysis (EDS), and X-ray diffraction phase analysis in Bragg-Brentano geometry. It was found that for all the test temperatures, the material was oxidized roughly in accordance with parabolic law. The resulting scale was compact and continuous at lower oxidation temperatures. The analysis of the recorded diffraction patterns allowed detection in the examined scale the presence of the following phases: Cr2O3 MnCr2O4, (Cr, Fe)2O3, SiO2 and CrNbO4.

19

Kalibracja instalacji różnicowania ciśnienia. Wybrane problemy w kontekście prowadzenia prób odbiorowych

Zapała R., Szumski M.

Chłodnictwo i Klimatyzacja

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2012

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nr 3

38-40

20

The studies of scale surface produced on outer diffusion layers

Augustyn-Pieniążek J., Zapała R.

Archives of Foundry Engineering

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2011

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Vol. 11, iss. 2 spec.

5--8

EN

In this study at attempt was made to examine the scale formed on ferritic-austenitic duplex type steel subjected to previous thermo-chemical treatment. The treatment consisted in diffusion aluminising in a metallising mixture composed of Fe-Al powder. As an activator, ammonium chloride (NH4Cl) added in an amount of 2 wt.% was used. Then, both the base material and samples with the diffusion-deposited surface layers were oxidised at 1000°C in the air. Thus formed scales were identified by light microscopy, SEM and X-ray phase analysis. The aim of the oxidation tests carried out under isothermal conditions was to compare the scale morphology when obtained on untreated substrate material and on the surface layers rich in aluminium.