Ograniczanie wyników
Czasopisma help
Autorzy help
Lata help
Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 169

Liczba wyników na stronie
first rewind previous Strona / 9 next fast forward last
Wyniki wyszukiwania
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 9 next fast forward last
EN
The article presents the technology of layered casting with the use of 3D printing to make a frame insert. The insert was made of powdered titanium and then filled with liquid cast iron. The paper presents the results of research, including structure observation and hardness measurements, as well as abrasion resistance tests. The results indicate the possibility of creating a local reinforcement using a frame insert. The resulting casting is characterized by a local increase in hardness and, in addition, an increase in abrasion resistance of the entire surface layer. The quality of the obtained connection depends strongly on the casting parameters.
EN
The paper presents a method of producing a grey cast iron casting locally reinforced with a titanium insert printed using SLM method (Selective Laser Melting). This article attempts to examine the impact of the selected geometry of titanium spatial insert on the surface layer formation on grey cast iron. The scope of the research focuses on metallographic examination - observation and analysis of the structure of the reinforced surface layer on a light and scanning microscope and a hardness measurement of the titanium layer area. Based on the obtained results, it was concluded that the reaction between titanium insert and metal (grey cast iron) locally develops numerous carbides precipitation (mainly TiC particles), which increases the hardness of the reinforced surface layer and local strengthening of the material. The ratio between the thickness of the support part (grey cast iron) and the working part (titanium insert) affects the resulting layers connection structure. The properties of the obtained reinforced surface layer depend mainly on the geometry of the insert (primarily on the internal dimensions of the connector) and the volume of the casting affecting the re-melting of the insert. A more concentrated structure of carbides precipitation occurs in castings with a full connector insert.
EN
The paper presents selected granular ceramic materials available on the Polish market. Their characteristics have been determined in the aspect on application in the production of iron alloy-ceramic composite. The possibility of obtaining a composite layer by means of bulk grains in molds of plates were considered, which was the foundation for experimental molds to be used in service tests. On the basis of obtaining results was stated that the knowledge of the characteristics of bulk grains enables the calculation of their quantity necessary for the composite production. When using the bulk grains the thickness of the composite layer is restricted by the thermal relations (cooler) and the physical phenomena (buoyancy, metal static pressure). Increasing amount of grains above definite condition causes surface defects in the castings. Each casting, due to its weight, shape and place of composite layer production requires an individual approach, both at the stage of formation and that of calculation of the required quantity of ceramic grains.
EN
The paper presents an innovative method of creating the layered castings. The innovation relies on application the 3D printing insert obtaining in SLM (selective laser melting) method. This type of scaffold insert made from pure Ti powder, was placed into mould cavity directly before pouring by grey cast iron. In result of used method was obtained grey cast iron casting with surface layer reinforced by titanium carbides. In range of studies were carried out metallographic researches using light microscope and scanning electron microscope, microhardness measurements and abrasive wear resistance. On the basis of obtaining results was stated that there is a possibility of reinforcing surface layer of the grey cast iron casting by using 3D printing scaffold insert in the method of mould cavity preparation. Moreover there was a local increase in hardness and abrasive wear resistance in spite of the precipitation of titanium carbides in surface layer of grey cast iron. While the usable properties of composite surface layer obtained in result of use of the method presented in the paper, strongly depend of dimensions of scaffold insert, mainly parameters Re and Ri.
5
Content available Cast Iron Reinforced with Foaming Ceramic Insert
EN
This paper presents matters related to production of ceramic and cast iron composite. The composite was made with the use of a foam structured ceramic insert. The tests included measuring of hardness, impact strength and resistance to abrasive wear of the composite produced. On the basis of obtaining results was stated that the use of foamed ceramic filters provides good conditions of filling a ceramic framework with molten grey or chromium cast iron. The growth of hardness of the ceramic-grey cast iron composite is ca. 60% as compared to the grey cast iron hardness. The growth of hardness of the ceramic-chromium cast iron composite is slight and does not exceed 5 % in comparison to the chromium cast iron. Introduction of the ceramic inserts deteriorates the cast iron impact strength by ca. 20 - 30 %. The use of ceramic inserts increases the resistance to abrasive wear in case of grey cast iron by ca. 13% and in case of the chromium cast iron by ca. 10 %.
EN
In this paper, we presented the technology of layered castings based on the founding method of layer coating directly in the cast process known as the method of mold cavity preparation by monolithic or granular material of insert. Prepared castings consist of two fundamental parts: the base part and working part (layer). The base part of a layered casting is usually typical foundry material (i.e., pearlitic grey cast iron with flake graphite or ferritic-pearlitic carbon cast steel), whereas the dependence of an insert type (i.e., monolithic or granular) working part (layer) is suitably plated with ferrit‑ ic and austenitic alloy steels or a layer from a Cr-base alloy. The ratio of thickness between the base and working part is between 8:1 and 10:1. The quality of the layered castings was evaluated on the basis of ultrasonic non-destructive test‑ ing, structure, and selected usable property research. According to work out technology, the prepared layered castings can work in conditions that require high heat resistance and/or corrosion resistance from the working surface layer of an element in a medium of industrial water, for example. Moreover, in the case of applying an insert based on Cr-base alloy powder on the working surface layer, it is possible to obtain high hardness and abrasive wear resistance.
EN
The aim of paper was determination of influence of the casting velocity in horizontal continuous casting process on solidification phenomenon and next primary structure of aluminum ingots. In the range of studies was conducted the experiment concerning continuous casting of Al ingots with diameter 30 mm at velocity from 30 to 80 mm/min. Moreover was developed adequate to the real the virtual model of cooled water continuous casting mould, which was used in simulation of solidification process of Al continuous ingot, made in ANSYS Fluent software. In result was determined the influence of casting velocity and temperature of cooling water on position of crystallization front inside the continuous casting mould. While the shape and size of grains in primary structure of Al continuous ingots were determined on the basis of metallographic macroscopic studies. On the basis of the results analysis was affirmed that increase of casting velocity strongly influences on position of crystallization front and causes increase of temperature of ingot leaving the continuous casting mould. In result the increase of casting velocity supposedly leads to decrease of temperature gradient on crystallization front what creates coarse grains in primary structure of aluminum continuous ingots and caused low usable properties i.e. suitability to plastic deformation.
8
Content available Reinforcing cast iron with composite insert
EN
The paper presents a proprietary method of making composite cast iron (eutectic) locally reinforced with ceramics. The research included making casts with a ceramic layer, its percentage of the surface was 30%. The research included abrasive wear resistance according to ASTM G 65-00. As a result of the research it has been found that the infiltration of the molten metal into the ceramic preform mainly affects the correct production of the cast with local reinforcement. The research results also have proven that the application of a lattice ceramic insert placed in the mould is the most appropriate option, due to the even distribution of the particles in the cast and obtaining a sound cast.
EN
The paper presents the research results of horizontal continuous casting of ingots of aluminium alloy containing 2% wt. silicon (AlSi2). Together with the casting velocity (velocity of ingot movement) we considered the influence of electromagnetic stirring in the area of the continuous casting mould on refinement of the ingot’s primary structure and their selected mechanical properties, i.e. tensile strength, yield strength, hardness and elongation. The effect of primary structure refinement and mechanical properties obtained by electromagnetic stirring was compared with refinement obtained by using traditional inoculation, which consists in introducing additives, i.e. Ti, B and Sr, to the metal bath. On the basis of the obtained results we confirmed that inoculation done by electromagnetic stirring in the range of the continuous casting mould guarantees improved mechanical properties and also decreases the negative influence of casting velocity, thus increasing the structure of AlSi2 continuous ingots.
PL
W pracy przedstawiono wyniki dotyczące modyfikacji metodą mieszania elektromagnetycznego wybranych podeutektycznych stopów aluminium z krzemem gatunku AlSi2 i AlSi7. Celem realizacji procesu modyfikacji zastosowano mieszadło zasilane prądem o podwyższonej częstotliwości, wytwarzające wirujące pole elektromagnetyczne. Skuteczność modyfikacji oceniono na podstawie wyników badań metalograficznych makro- i mikroskopowych. Ponadto przedstawiono możliwość aplikacji uzyskanych wyników badań w procesie poziomego odlewania ciągłego stopów Al-Si.
EN
In this research paper results concerning the inoculation method based on electromagnetic stirring of hypoeutectic aluminum with silicon alloys AlSi2 and AlSi7 grade are presented. The inoculation process used a stirrer supplied by current with a high frequency, generating a rotating electromagnetic field. The efficiency of inoculation was estimated in the results of the metallographic macro- and microscopic research. Moreover, the possibility of using the obtained results in horizontal continuous casting process of Al-Si alloys was presented.
EN
In the paper analysis of temperature gradient and parameters of structure on casting cross-section of abrasive wear resistant chromium cast iron at carbon content of 2,5%wt. and chromium 17%wt. with nickel and molybdenum additives are presented. The castings were made with use of special tester ϕ100mm (method of temperature gradient and derivative analysis) with temperature recording in many points from thermal centre to surface (to mould) of casting. Registered cooling curves were used to describe the temperature gradient on cross-section of analyzed casting. On the basis of determined curves of temperature gradient measurement fields were selected to make the quantitative studies of structure. The results of studies show significant influence of temperature gradient on quantitative parameters of chromium cast iron structure. Moreover was affirmed that exists a critical temperature gradient for which is present rapid change of quantitative parameters of chromium cast iron structure.
PL
W artykule przedstawiono analizę gradientu temperatury i parametrów struktury lanej na przekroju odlewu wykonanego z żeliwa chromowego odpornego na zużycie ścierne o zawartości węgla ok. 2.5% i chromu ok. 17% z dodatkami niklu i molibdenu. Odlew wykonano w specjalnym próbniku ϕ100mm (metoda analizy gradientu temperatury i derywacyjna) z pomiarem temperatury w wielu punktach odlewu od jego centrum cieplnego do powierzchni (do formy odlewniczej). Zarejestrowane krzywe stygnięcia wykorzystano do opisu gradientu temperatury na przekroju analizowanego odlewu. Badania ilościowe struktury wykonano na wybranych przekrojach odlewu. Analizowane przekroje wybrano na podstawie wyznaczonych krzywych gradientu temperatury. Badania wykazały istotny wpływ gradientu temperatury na parametry ilościowe struktury żeliwa chromowego. Stwierdzono występowanie krytycznego gradientu temperatury, dla którego następuje skokowa zmiana parametrów ilościowych struktury badanego żeliwa chromowego.
EN
In the article there are presented methods and results of investigation which main aim were determination of influence of melting technology (gas extraction, vacuum refining, slag refining and extraction, deoxidation and degassing) and type of used modifiers on the type and shape of non-metallic inclusions and the primary structure refining. Low alloy cast steel melted in laboratory conditions, in an inductive furnace was investigated. Additions of FeNb, FeV, FeTi and FeZr modifiers were applied. The contents of oxygen and nitrogen in obtained cast steel were determined. The most advantageous impact on refining of the primary structure of has been found for the modifiers FeTi+FeZr. In cast steel with the addition of Zr the conglomerates from a different non -metallic inclusions have been observed. Zirconium probably plays role of the nucleus - creating for other inclusions present in the conglomerates. Clusters of inclusions due to their size affect the crystallization and grain growth processes reducing grain size of the primary structure.
PL
W pracy przedstawiono założenia, metodykę i wyniki badań, których celem było określenie wpływu technologii wytopu (ekstrakcji gazowej, rafinacji próżniowej, rafinacji i ekstrakcji żużlowej, odtleniania i odgazowania) i rodzajów zastosowanych modyfikatorów na postać i rodzaj wtrąceń niemetalicznych oraz rozdrobnienie struktury pierwotnej. Analizie poddano nisko-stopowe staliwo wytopione w warunkach laboratoryjnych w piecu indukcyjnym. Zastosowano dodatek modyfikatorów FeNb, FeV, FeTi i FeZr. W uzyskanym staliwie określono zawartość O i N oraz jego skład chemiczny. Stwierdzono najkorzystniejsze, ze względu na rozdrobnienie struktury pierwotnej, oddziaływanie modyfikatora FeTi+FeZr. Zaobserwowano występowanie konglomeratów różnych wtrąceń niemetalicznych w staliwach z dodatkiem Zr, który prawdopodobnie działa zarodkotwórczo na pozostałe wtrącenia wchodzące w skład konglomeratów. Skupiska wtrąceń ze względu na swoje rozmiary wpływały na krystalizację i wzrost ziaren staliwa rozdrabniając jego strukturę pierwotną.
EN
A description of alloy layer formation on a steel substrate is presented. Two types of formation are considered: diffusion of carbon and chromium into the solid from the pad in the direction of the cast steel within the FeCrC (grains) and diffusion in a layer of liquid chromium cast iron formed in a preceding step. The influence of silicon in the pad on the pad’s transformation into the liquid is also examined. Solidus and liquidus temperatures of high carbon ferrochromium are determined. The larger the content of Si is used in the experiment, the lower the solidus temperature of the FeCrC alloy is observed. This results from the higher intensity of the elements’ diffusion and faster formation of the liquid.
PL
W pracy przedstawiono autorski opis procesu powstawania powierzchniowej warstwy stopowej, którego istota opiera się na dyfuzji w stanie stałym węgla i chromu z wkładki w stronę staliwa w obrębie ziaren FeCrC, jak również na dyfuzji w warstwie ciekłego żeliwa chromowego powstałego w wcześniejszych etapach tworzenia się warstwy w wyniku dyfuzji w stanie stałym. Zbadano również wpływ dodatku krzemu w materiale wkładki stopowej na proces przejścia jej w stan ciekły. Określono temperaturę likwidus i solidus żelazochromu wysokowęglowego mającą wpływ na ten proces. Stwierdzono, że zwiększona zawartość Si powoduje obniżenie temperatury solidus stopu FeCrC co jest powodem zwiększenia szybkości dyfundujących składników, co z kolei prowadzi do szybszego powstania fazy ciekłej.
EN
The paper presents the problem of obtaining a permanent diffusional joint between the working surface layer and the base part in a bimetallic casting. The studied bimetallic casting was obtained as a result of using the founding method of layer coating directly in the cast process. The casting prepared using this method consists of two fundamental parts, i.e., the grey cast iron base and the working surface layer which constitutes of X6Cr 13 high-chromium stainless steels plate. Based on the obtained results it was confirmed that the decisive phenomena that are needed to create a permanent joint between the two components of the bimetallic casting are carbon and heat transport from the high-carbon and hot base material which was poured into the mould in the form of liquid metal to the low-carbon and cold material of the working layer which was placed in the mould cavity in the form of a monolithic insert.
PL
W pracy przedstawiono problematykę uzyskiwania trwałego połączenia pomiędzy warstwą roboczą a częścią nośną w odlewie bimetalowym, który został wykonany przy użyciu metody nakładania warstw bezpośrednio w procesie odlewania. Wykonane tą metodą odlewy złożone są z dwóch zasadniczych elementów tj. części nośnej z żeliwa szarego oraz warstwy roboczej, którą stanowi blacha ze stali ferrytycznej odpornej na korozję gatunku X6Cr 13. Stwierdzono, że zjawiskami decydującymi o utworzeniu trwałego połączenia pomiędzy łączonymi tworzywami składowymi bimetalicznego odlewu warstwowego jest transport węgla i ciepła w kierunku od wysokowęglowego i gorącego materiału części nośnej wlewanego do formy w postaci ciekłego metalu do niskowęglowego i zimnego materiału warstwy roboczej umieszczanego w postaci wkładki monolitycznej we wnęce formy.
EN
Silicon cast iron with high chemical resistance, which is the biggest advantage of this material, did not have any competition for a long time. It was popular on the market of metal materials because of its low price. However, the production of this material requires special attention and precautions, which is a barrier for foundry. The article presents the results of research of high silicon cast iron crystallization based on thermal derivative analysis (which has identified characteristic temperatures of the investigated alloy crystallization process basis on the part of Fe–Si phase diagram and process analysis using calculations made in Thermo–Calc software) and metallographic analysis of the structure.
EN
In paper is presented results of studies concerning ingot of Al with a purity of 99.5% cast with use of stand of horizontal continuous casting. Mainly together with casting velocity was considered influence of electromagnetic stirrer, which was placed in continuous casting mould on refinement of ingots structure and theirs usability to plastic deformation. Effect of structure refinement and usability to plastic deformation obtained by influence of electromagnetic stirring was compared with refinement obtained by use of traditional inoculation, which consists in introducing of additives i.e. Ti and B to metal bath. On the basis of obtained results was affirmed that inoculation realized by electromagnetic stirring in range of continuous casting mould guarantees improvement in structure refinement and usability to rolling of pure Al continuous ingots.
EN
The results of research on stereological parameters of carbides in modified hypoeutectic chromium cast iron were shown in the paper. The effect of distance the casting heat centre of casting to the carbide phase morphology was examined. The samples for metallographic examination were taken from various locations of the model casting prepared in a special tester. This model casting was designed to simulate the solidification of heavy castings. Using the proposed methodology the relation of the distance from the model mould and the size, perimeter, length, width and the shape factor of carbides was examined. During the analysis, the values of stereological parameters of carbides changed on various sections of the model casting.
EN
The article shows results of studies of primary crystallization and wear resistance of Cr-Ni-Mo cast steel intended for work in corrosive and abrasive conditions. The studies of primary crystallization were conducted with use of TDA method and modified tester allowing measurement casting cooling time influence on the cooling and crystallization curves of studied alloys. After heat treatment of examined cast steel wear tests of the samples were conducted on pin-on-disc type device.
EN
In the paper the results and analysis of corrosion tests were presented for low-alloyed cast steel in as-cast state and after heat treatment operations. Such alloys are applied for heavy loaded parts manufacturing, especially for mining industry. The corrosion test were performed in conditions of high salinity, similar to those occurring during the coal mining. The results have shown, that small changes in chemical composition and the heat treatment influence significantly the corrosion behaviour of studied low-alloyed cast steels.
EN
In the paper the results and analysis of abrasive wear studies were shown for two grades of cast steels: low-alloyed cast steel applied for heavy machinery parts such as housing, covers etc. and chromium cast steels applied for kinetic nodes of pin-sleeve type. Studies were performed using the modified in Department of Foundry pin-on-disc method.
first rewind previous Strona / 9 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.