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EN
The paper presents the problem which concerning the technology of bimetallic castings in materials configuration: high-chromium steel as the working layer and grey cast iron as the base part. The aim of the studies was integrate the process of manufacturing of bimetallic casting with the heat treatment of hardening type of X46Cr13 steel insert by applying the mould with sandmix on a matrix of chromite sand. Range of studies included the chemical composition analysis, non-destructive ultrasonic tests to examine the quality of the permanent bond between the working layer (steel insert) and the base part (grey cast iron) of the bimetallic castings, hardness measurements as well as metallographic examinations performed on the optical and scanning electron microscopes. On the basis of obtained results was concluded that the self-hardening process occurred in the X46Cr13 steel working layer and in result of this the hardness on its surface equalled approx. 45HRC in case of the bimetallic castings with full permanent bond between both parts.
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.
6
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.
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
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
In paper a method of improvement in utility properties of unalloyed cast steel casting in result of diffusion of C and Cr in process of creation of surface layer is presented. The aim of paper was determination of diffusion range of basic elements of alloyed surface layer. Moreover a quantitative analysis of carbides phase strengthens alloyed surface layer of casting was carried out. The results of studies shown that important factors of surface layer creation are maximal temperature Tmax on granular insert – cast steel boundary dependent of pouring temperature, granularity Zw of Fe-Cr-C alloy insert and thickness of casting wall gśo. On the basis of obtained results was affirmed that with increase of thickness of casting wall increases range of diffusion in solid state in Fe-Cr-C grains and in liquid state. Moreover the range of Tmax = 13001500°C favours creation of the proper alloyed surface layers on cast steel.
PL
W pracy przedstawiono metodę poprawy własności użytkowych odlewów ze staliwa niestopowego w wyniku dyfuzji C i Cr występującej w procesie wytwarzania warstwy wierzchniej. Zasadniczym celem badań było określenie zasięgu dyfuzji podstawowych składników wierzchniej warstwy stopowej. Badania obejmowały również analizę ilościową powstałej fazy węglikowej umacniającej warstwę wierzchnią odlewu. Wyniki badań oraz ich analiza wykazały, że istotnymi zmiennymi czynnikami procesu powstawania warstwy są maksymalna temperatura Tmax osiągana na granicy ziarnista wkładka – staliwo zależna od temperatury zalewania, ziarnistość Zw wkładki z stopu Fe-Cr-C i grubość ścianki odlewu gśo. Na podstawie uzyskanych wyników stwierdzono, że wraz ze wzrostem grubości ścianki odlewu rośnie zasięg procesów dyfuzyjnych zarówno w stanie stałym w ziarnach Fe-Cr-C jak i w stanie ciekłym. Ponadto zakres Tmax = 13001500°C sprzyja powstaniu prawidłowej powierzchniowej warstwy stopowej na staliwie.
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