The objective of the research was to determine the influence of boron on the crystallization process and microstructure of ductile cast iron.
In the case of ductile cast iron it is a vital issue because even as little as trace presence of boron changes the properties of ductile cast iron
in a significant way. With the use of a new ATD-4 (TDA) tester and CRYSTALDIGRPAH converter it was possible to measure the
crystallization process parameters of the same alloy with four different contents of boron in one mould. Four samples with different boron
contents were extracted, their microhardness was measured and quantitative analysis of microstructure was conducted. Obtained results
allowed to state that with increasing content of boron the amount of graphite precipitates decreases, the amount of pearlite precipitates
increases, the shape of graphite precipitates deteriorates and hardness increases. It is also planned to perform additional testings with boron
contents between previously tested values.
The aim of presented studies was to develop a new geometry of the overflow part of standard ATD–C tester for derivative thermal analysis
in a way that it would allow to obtain samples for abrasion and mechanical properties tests in the same mould without the need of cutting
them from a block of material. The pattern of new ATD–P tester has parts reflecting implemented samples. Computer simulations
regarding initial verification of new tester were performed in NovaFlow software. Chromium cast iron melts were made for testing the
sampler in real conditions and TDA analysis for casting material were conducted. The sandmix was prepared on silica sand matrix per the
ALPHASET technology. This new solution greatly simplifies the preparations of materials difficult to machine.
Paper presents the results of studies on primary crystallization and wear resistance of high chromium cast iron inoculated with
ferrotitanium intended for work in abrasive conditions. Primary crystallization was examined with use of TDA method, wear tests of the
samples were conducted using the modified pin-on-disk method.
The article is a case study of the steel milling ring casting of about 6 tonnes net weight. The casting has been cast in the steel foundry the authors have been cooperating with. The aim was to analyse the influence of the shape of the chills and the material which was used to make them on the casting crystallization process. To optimally design the chills the set of the computer simulation has been carried out with 3 chills’ shape versions and 3 material’s versions and the results have been compared with the technology being in use (no chills). The proposed chills were of different thermal conductivity from low to high. Their shapes were obviously dependant on the adjacent casting surface geometry but were the result of the attempt to optimise their effect with the minimum weight, too. The chills working efficiency was analysed jointly with the previously designed top feeders system. The following parameters have been chosen to compare their effectiveness and the crystallization process: time to complete solidification and so-called fed volume describing the casting feeding efficiency. The computer simulations have been carried out with use of MagmaSoft v. 5.2 software. Finally, the optimisation has led to 15% better steel yield thanks to 60% top feeders weight reduction and 40% shorter solidification time. The steel ring cast with use of such technology fulfil all quality criteria.