A R C H I V E S of F O U N D R Y E N G I N E E R I N G Effect of Ti, Nb, Cr and B on Structure and Mechanical Properties of High Aluminium Cast Iron

Abstract In this work, a method was investigated to eliminate the presence of undesirable Al 4 C 3 phases in a high-aluminium alloys, and thus improve the production process. The melting conditions employed in this work enabled the formation of a Fe-Al-C liquid solution. Moreover, titanium additions into the liquid allowed the precipitation of TiC. According to this reaction, the extent of carbon removal from the melt is strongly influenced by the amount of Ti additions. Hence, proper titanium levels can result in total removal of carbon from the liquid. Notice from this figure that Ti additions above 4.5%, totally eliminate the undesirable Al 4 C 3 precipitates. Making Cr, Ti, B additions reduces size of FeAl alloys grains. In addition, this work indicates that the high-aluminium cast iron posses high oxidation resistance, exceeding that of high-chromium cast iron and chromium cast steels. Finally, the alloy ductility can be enhanced by additions of dopants such as B and Cr. Hence, additions of 0.03% B and 0.03%B-5% Cr combined with a heat treatment were implemented. As a result, the alloy ductility was significantly improved, where the strain of up to 5.3%, (B alone) or 15% (B-Cr) were obtained

Effect of Ti, Nb, Cr and B on structure and mechanical properties of high aluminium cast iron

In this work, a method was investigated to eliminate the presence of undesirable Al4C3 phases in a high-aluminium alloys, and thus improve the production process. The melting conditions employed in this work enabled the formation of a Fe-Al-C liquid solution. Moreover, titanium additions into the liquid allowed the precipitation of TiC. According to this reaction, the extent of carbon removal from the melt is strongly influenced by the amount of Ti additions. Hence, proper titanium levels can result in total removal of carbon from the liquid. Notice from this figure that Ti additions above 4.5%, totally eliminate the undesirable Al4C3 precipitates. Making Cr, Ti, B additions reduces size of FeAl alloys grains. In addition, this work indicates that the high-aluminium cast iron posses high oxidation resistance, exceeding that of high-chromium cast iron and chromium cast steels. Finally, the alloy ductility can be enhanced by additions of dopants such as B and Cr. Hence, additions of 0.03% B and 0.03%B-5% Cr combined with a heat treatment were implemented. As a result, the alloy ductility was significantly improved, where the strain of up to 5.3%, (B alone) or 15% (B-Cr) were obtained

Analysis of the structure of castings made from chromium white cast iron resistant to abrasive wear. Archives of Foundry Engineering

Abstract It has been proved that an addition of boron carbide and disintegrated steel scrap introduced as an inoculant to the chromium white cast iron changes the structure of castings. The said operation increases the number of crystallization nuclei for dendrites of the primary austenite. In this case, the iron particles act as substrates for the nucleation of primary austenite due to a similar crystallographic lattice. The more numerous are the dendrites of primary austenite and the structure more refined and the mechanical properties higher. Castings after B 4 C inoculation revealed a different structure of fine grained fracture. Primary precipitates of chromium carbide also appeared, reducing the mechanical properties of as-cast parts. Properly established heat treatment regime makes chromium iron castings regain their, originally high, mechanical properties

Effect of Ti, Nb, Cr and B on Structure and Mechanical Properties of High Aluminium Cast Iron

In this work, a method was investigated to eliminate the presence of undesirable Al4C3 phases in a high-aluminium alloys, and thusimprove the production process. The melting conditions employed in this work enabled the formation of a Fe-Al-C liquid solution.Moreover, titanium additions into the liquid allowed the precipitation of TiC. According to this reaction, the extent of carbon removal from the melt is strongly influenced by the amount of Ti additions. Hence, proper titanium levels can result in total removal of carbon from the liquid. Notice from this figure that Ti additions above 4.5%, totally eliminate the undesirable Al4C3 precipitates. Making Cr, Ti, B additions reduces size of FeAl alloys grains. In addition, this work indicates that the high-aluminium cast iron posses high oxidation resistance, exceeding that of high-chromium cast iron and chromium cast steels. Finally, the alloy ductility can be enhanced by additions of dopants such as B and Cr. Hence, additions of 0.03% B and 0.03%B-5% Cr combined with a heat treatment were implemented. As a result, the alloy ductility was significantly improved, where the strain of up to 5.3%, (B alone) or 15% (B-Cr) were obtained

Wpływ temperatury odlewania na strukturę i właściwości mechaniczne żeliwa wysokochromowego

The article presents the results of the influence of pouring temperature on the structure and selected properties of high-chromium cast iron. The study was performed on two different pouring temperatures 1490°C and 1460°C for cast iron of the same chemical composition. Melts were performed in the induction furnace crucible capacity of 15 kg located in the Department of Engineering Alloys and Composites in Foundry Engineering Faculty of AGH. For each temperature cast 2 sets of rollers with dimensions ø30mm, ø20mm, ø15mm x 250mm. During the heats poured cup with installed S type thermocouple to record the cooling curves. Rollers put to the static bending strength test. Samples were cut from the rollers for the test microstructure. The study shown that the pouring temperature has a significant impact on the way of crystallization of high-chromium cast iron and consequently, on the microstructure and mechanical properties. It follows that, by appropriate selection of the pouring temperature can control certain properties of the casting.W pracy przedstawiono wyniki badań wpływu temperatury odlewania na strukturę i wybrane właściwości wytrzymałościowe żeliwa wysokochromowego. W ramach badań wykonano dwa wytopy z różną wartością temperatury odlewania 1490 °C i 1460 °C, dla żeliwa o tym samym składzie chemicznym. Wytopy wykonano w piecu indukcyjnym o pojemności tygla 15 kg znajdującym się w Katedrze Inżynierii Stopów i Kompozytów Odlewanych na Wydziale Odlewnictwa AGH. Dla każdej temperatury odlano 2 zestawy wałków o wymiarach ø30 mm, ø20 mm, ø15 mm x 250 mm. Podczas wytopów zalano kubki pomiarowe z termoelementem typu S do rejestracji krzywej krystalizacji i stygnięcia. Wałki poddano statycznej próbie wytrzymałości na zginanie. Następnie z wałków wycięto próbki do badania mikrostruktury. Z przeprowadzonych badań wynika, że temperatura odlewania ma istotny wpływ na sposób krystalizacji odlewu z żeliwa wysokochromowego, a w konsekwencji na mikrostrukturę i właściwości wytrzymałościowe. Wynika z tego, że przez odpowiedni dobór temperatury odlewania można sterować niektórymi właściwościami mechanicznymi odlewu

Phase Analysis and Crystallographic Orientation of High Chromium Cast Iron Grain Using EBSD Technique

Grain orientation, properties, microstructure borders, and types and sizes of phases have had a major impact on the traits of modern engineering materials. Therefore, it is important to study, analyze, and (further) control the method of crystallizing alloys. One of the methods used to assess the orientation of grain growth is the EBSD technique. EBSD (Electron Backscatter Diffraction Analysis) enables us to perform quantitative analyses on the microstructure of materials (on a scale of millimetres to nanometres) in a scanning electron microscope. Using the EBSD technique can help us gain valuable information about the following properties of crystalline materials: crystal orientation, disorientation, grain boundaries, global and local texture, fractions recrystallization/deformation, stress analysis, characterization of intergranular boundaries, identification of phases, phase distribution, and so on. In this paper, we present the results of phase analysis and crystallographic orientation of the grains of high chromium cast iron via EBSD. These were preliminary studies to determine the possibility of using the EBSD technique for analyzing high chromium cast iron. Castings were produced under industrial conditions, then samples were cut out and testing using the EBSD technique. This method proved to be effective for this type of material

Influence of tungsten and titanium on the structure of chromium cast iron

The paper analyses the as-cast state structure of chromium cast iron designed for operation under harsh impact-abrasive conditions. In the process of chromium iron castings manufacture, very strong influence on the structure of this material have the parameters of the technological process. Among others, adding to the Fe-Cr-C alloy the alloying elements like tungsten and titanium leads to the formation of additional carbides in the structure of this cast iron, which may favourably affect the casting properties, including the resistance to abrasive wear

Wpływ topnika na wzrost faz perytektycznych w powłoce cynkowej

A model of the (Zn) – coating formation on the iron/steel substrate is proposed. The model assumes the phases’ sub-layers creation in a sequence. This sequence is referred to the Fe-Zn phase diagram. However, this sequence of phases’ appearance is perturbed by the flux presence in the zinc bath. The flux effect on the coating morphology and appearance/disappearing of some sub-layers is analysed. The phases’ formation is treated as the result of the peritectic reaction accompanying the coating solidification. A comparison of the coating formations before and after flux decay is delivered. Thus, a function which describes the flux decay is also analysed. Additionally, a ternary Fe-Zn-F(flux) phase diagram is considered. The varying zinc concentration across the phases sub-layers is described with the use of the function which determines the flux decay. The behaviour of the solidification path before and after flux decay is discussed due to the adequate equations formulated in frame of the current model.Zaproponowany został model kształtowania się powłoki (Zn) na podłożu ze stali/żelaza. Model zakłada powstawanie podwarstw faz w pewnej sekwencji. Sekwencja ta odniesiona jest do diagramu równowagowego. Jednak, sekwencja ta zakłócona jest obecnością topnika w kąpieli. Wpływ topnika na morfologię powłoki oraz na pojawianie się/zanik niektórych podwarstw jest analizowany. Powstawanie faz traktowane jest jako rezultat reakcji perytektycznych towarzyszących krystalizacji powłoki. Pokazane jest porównanie kształtowania się powłoki przed i po zaniku topnika. Stąd, analizowana jest również funkcja, która opisuje zanik topnika. Dodatkowo, rozważany jest potrójny diagram fazowy Fe-Zn-topnik. Zmienne stężenie cynku na grubości podwarstw opisane jest z użyciem funkcji, która opisuje zanik topnika. Zachowanie się ścieżki krystalizacji przed i po zaniku topnika jest dyskutowane w odniesieniu do stosownych równań sformułowanych w proponowanym modelu