Wyniki wyszukiwania - BazTech

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Thermal Deformation of Moulding and Core Sands with an Inorganic Binder Containing a Relaxation Additive

Bobrowski A., Drożyński D., Jakubski J., Szumera M., Kaczmarska K., Grabowska B.

Archives of Foundry Engineering

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2018

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Vol. 18, iss. 4

93--98

EN

The paper presents the results of an investigation of the thermal deformation of moulding sands with an inorganic (geopolymer) binder with a relaxation additive, whose main task is to reduce the final (residual) strength and improves knocking-out properties of moulding sand. The moulding sand without a relaxation additive was the reference point. The research was carried out using the hot-distortion method (DMA apparatus from Multiserw-Morek). The results were combined with linear deformation studies with determination of the linear expansion factor (Netzsch DIL 402C dilatometer). The study showed that the introduction of relaxation additive has a positive effect on the thermal stability of moulding sand by limiting the measured deformation value, in relation to the moulding sand without additive. In addition, a relaxation additive slightly changes the course of the dilatometric curve. Change in the linear dimension of the moulding sand sample with the relaxation additive differs by only 0.05%, in comparison to the moulding sand without additive.

2

Influence of Pre-heat Treatment on Mechanical Properties of Austempered Ductile Cast Iron

Nawrocki P., Wasiluk K., Łukasik K., Myszka D.

Archives of Foundry Engineering

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2018

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Vol. 18, iss. 1

176--180

EN

The paper presents the effect of pre-heat treatment on the mechanical properties of ductile cast iron with elevated content of Cu and Mo elements. Austempered Ductile Iron is a material with non-standard properties, combining high tensile strength and abrasion resistance with very good plasticity. In addition, it is prone to strain hardening and have good machining abilities. The study was conducted for five designed heat treatment cycles. The variables were the time and temperature of the pre-heat treatment, followed by one of two standard heat treatments for ADI cast iron. The aim of the authors was fragmentation of the grains of perlite during the initial heat treatment. It is presumed, that subsequent heat treatment will cause further refinement of the microstructure than would be the case without initial heat treatment. Diffusion is much faster than in case of ferritic matrix of cast iron. The results will be used to evaluate material for the production of parts of equipment that must operate under extreme load conditions.

3

The Microstructure and Phase Composition of 35CrSiMN5-5-4 Steel After Quenching and Partitioning Heat Treatment

Skołek E., Wasiak K., Świątnicki W. A.

Archives of Metallurgy and Materials

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2016

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Vol. 61, iss. 3

1683--1688

EN

The aim of the study was to characterise the microstructure of 35CrSiMn5-5-4 steel which was subjected to a new heat treatment technology of quenching and partitioning (Q&P). The parameters of the treatment were chosen on the basis of computer simulations and dilatometric studies of phase transformations occurring in steel. The transmission electron microscopy (TEM) observations of steel microstructure after the Q&P treatment revealed the presence of martensite as well as significant amount of retained austenite in form of layers between the martensite laths. The rod-like carbides in the ferritic areas were also observed, which indicates the presence of lower bainite in steel. It was found that the retained austenite content measured by means of TEM was about 28% for partitioning at 400°C and 25% for partitioning at 260°C. These results are in good agreement with the phase composition calculated theoretically as well as those determined experimentally by use of dilatometric tests.

4

Wpływ parametrów procesu spiekania na strukturę materiałów żelazo-brąz.

Frydrych H., Konstanty J., Sowa M., Olszewska I., Goleń R.

Rudy i Metale Nieżelazne

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1999

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R. 44, nr 7

355-360

PL

Wykonano szczegółową analizę wyników badań dylatometrycznych. Prześledzono również zmiany struktury zachodzące podczas procesu spiekania. Określono także metodami metalografii ilościowej udział objętościowy brązu penetrującego pomiędzy cząstkami żelaza, powierzchnię względną granic brąz-żelazo i powierzchnię właściwą ziarn brązu.

EN

A detailed analysis of the results of dilatometric studies is presented. The changes of the structure during sintering process were studied too. The quantitative participation of the penetrative bronze between the iron particles, the relative surface of the bronze grains were stated too by the methods of quantitative metallography.