Search Results

You are looking at 1 - 10 of 25 items for

  • Author: D. Kopyciński x
Clear All Modify Search
Open access

D. Kopyciński and S. Piasny

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.

Open access

E. Guzik, D. Kopyciński and D. Wierzchowski

Abstract

The use of two cored wire injection methods (2PE- 9) and the unique application of a drum ladle as a treatment, transport and casting one, instead of a vertical treatment ladle are presented. Optimization parameters, like: length of nodulariser wire, treatment and pouring temperature have been shown. The influence of various treatment temperatures on magnesium recovery is demonstrated. The typical microstructure, mechanical properties and cost calculation of the ferritic ductile cast iron (type SiMo - EN-GJS-SiMo40-6 Grade) production according to EN 16124:2011 (E) are presented. Injection of two Ø 9 mm as well wires; cored in FeSi + Mg nodulariser mixture and inoculant master alloy into a drum ladle is a treatment method that can be used for the production of ferritic ductile cast iron (SiMo) melted in a coreless induction furnace.

Open access

D. Kopyciński

Abstract

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.

Open access

D. Kopyciński, E. Guzik and A. Szczęsny

Abstract

It has been proved that an addition of boron carbide and shredded steel scrap introduced as an inoculants to the chromium white cast iron changes the microstructure of castings. The operation increases the number of crystallization nuclei of M7C3 carbides. In this case the B4C carbides act as substrates for the nucleation of M7C3 (chromium carbides). Castings after B4C inoculation have fine grain fracture surface. Primary precipitates of chromium carbide also appeared, lowering the mechanical properties of as-cast parts. Additionally, in order to increase the mechanical properties of chromium cast iron, unidirectional solidification was used. In this case, 0.3 wt. % cerium was used as inoculant.

Open access

D. Kopyciński, D. Siekaniec, A. Szczęsny, E. Guzik and A. Nowak

Abstract

The results of studies of the effect of different amounts of the Fe-Ti inoculant on structure and selected mechanical properties of High Chromium Cast Iron (conventionally abbreviated as HCCI) are presented. The main purpose of the inoculation is structure refinement and hence the improvement of casting properties. Generally considered a strong carbide-forming element, titanium is an effective inoculant for the high chromium cast iron. However, there is an optimal amount of titanium addition beyond which the mechanical properties begin to deteriorate. The studies enabled determining the amount of Fe-Ti inoculant optimal for the cast iron of a given chemical composition.

Open access

D. Kopyciński, E. Guzik, A. Nowak, M. Ronduda and M. Sokolnicki

Preparation Vermicular Graphite in Thin and Thick Wall Iron Castings

The results of studies on the use of magnesium alloy in modern Tundish for production of vermicular graphite cast irons were described. This paper describes the results of using a low-magnesium ferrosilicon alloy for the production of vermicular graphite cast irons. The paper presents a vermicular (and nodular) graphite in different walled castings. The results of trials have shown that the magnesium Tundish process can produce high quality vermicular graphite irons under the specific industrial conditions of Foundries - Odlewnie Polskie S.A. in Starachowice. In this work describes too preliminary studies on the oxygen state in cast iron and their effect on graphite crystallization.

Open access

D. Kopyciński, E. Guzik and A. Szczęsny

Abstract

Studies were conducted on a zinc coating produced on the surface of ductile iron grade EN-GJS-500-7 to determine the eutectic grain effect. For this purpose, castings with a wall thickness of 5 to 30 mm were made and the resulting structure was examined. To obtain a homogeneous metal matrix, samples were subjected to a ferritising annealing treatment. To enlarge the reaction surface, the top layer was removed from casting by machining. Then hot dip galvanising treatment was performed at 450°C to capture the kinetics of growth of the zinc coating (in the period from 60 to 600 seconds). Analysing the test results it was found that within the same time of hot dip galvanising, the differences in the resulting zinc coating thickness on samples taken from castings with different wall cross-sections were small but could, particularly for shorter times of treatment, reduce the continuity of the alloyed layer of the zinc coating.

Open access

D. Kopyciński and E. Guzik

Abstract

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.

Open access

A. Szczęsny, D. Kopyciński and E. Guzik

Abstract

Studies have demonstrated that in the process of hot dip galvanizing the decisive influence on the mechanism of zinc coating formation and properties has the quality of the mechanically untreated (raw) surface layer of the galvanized product. The terms “casting surface layer” denote various parameters of the microstructure, including the type of metal matrix, the number of grains and the size of graphite nodules, possible presence of hard spots (the precipitates of eutectic cementite) and parameters of the surface condition. The completed research has allowed linking the manufacturing technology of ductile iron castings with the process of hot dip galvanizing.

Open access

D. Kopyciński, E. Guzik and A. Szczęsny

Abstract

The completed research presented in the first part of the article has allowed linking the manufacturing technology of ductile iron castings with the process of hot dip galvanizing. On the basis of these data simulations were carried out to examine the behaviour of zinc diffusion coefficient D in the galvanized coating. The adopted model of zinc coating growth helped to explain the cases of excessive growth of the intermetallic phases in this type of coating. The paper analyzes covered the relationship between the roughness and phase composition of the top layer of product and the thickness and kinetics of zinc coating growth referred to individual sub-layers of the intermetallic phases.Roughness and phase composition in the surface layer of product were next related to the diffusion coefficient D examined in respective sublayers of the intermetallic phases.