Journal of Casting & Materials Engineering
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ISSN 2543-9901
Issue Date
2020
Volume
Vol. 4
Number
No. 4
Description
Journal Volume
Journal of Casting & Materials Engineering
Vol. 4 (2020)
Projects
Pages
Articles
Structures for heat treatment assembled from cast elements
(AGH University of Science and Technology Press, 2020) Piekarski, Bogdan; Drotlew, Andrzej
Various types of technological equipment individually designed for operation in pit and elevator heat treatment furnaces are described in this article. A common characteristic of these structures is that they are composed of several or several dozen thin-walled elements of various shapes and sizes, gravity cast in sand moulds from creep-resistant alloys (austenitic Cr-Ni/Ni-Cr cast steel and cast nickel alloys). The design of the castings requires the development of a manufacturing technology that can effectively use the principle of the simultaneous solidification of all components. Properly designed equipment should have minimum weight, maximum strength, and maximum loading capacity combined with adequate durability and reliability. Two designs of the equipment for the heat treatment of steel parts were presented. Both designs, as well as their individual components, were described in detail and illustrated. The main task of the equipment is to form the charge in the furnace and transport this charge both inside and outside the furnace. The first design is the design of an equipment for the heat treatment of large ring-shaped parts. The second design is the design of an equipment, whose structure can be modified using various repeatable components. As a result of these modifications, different variants of the equipment are obtained, allowing for the heat treatment of five different types of the shafts characterized by different shapes and sizes. The study is of an application nature. It is addressed to engineering and technical staff dealing with both the design and operation of heat treatment furnaces.
An evaluation of the effect of ultrasonic degassing on components produced by high pressure die casting
(AGH University of Science and Technology Press, 2020) Silva López, Manel da; Bajusz, Attila; Pabel, Thomas; Petkov, Tose; Plantà, Xavier
Ultrasonic treatment is known to be efficient for aluminium melt degassing with the additional benefits of being both economical and environment friendly. This paper describes the effect of ultrasonic degassing on the preparation of an AlSi9Cu3(Fe) alloy for High Pressure Die Casting (HPDC). The degassing efficiency was assessed in terms of the indirect evaluation of the melt, by means of the reduced pressure test and the porosity evaluation of the cast parts. Additionally, the corresponding hydrogen content was estimated with an experimental equation reported in the literature. Ultrasonic degassing shows greater efficiency in terms of hydrogen removal from the melt than conventional N$_{2}$ + Ar lance bubbling. Components produced by HPDC without degassing, with ultrasonic degassing and with lance degassing, were analysed by computed tomography and by metallography. The results show that the components produced by HPDC after ultrasonic degassing have a similar porosity level to components degassed with conventional lance bubbling, both showing an important improvement over components produced without degassing treatment. Hardness values were similar for all different treatment conditions and well over the minimum value established for the alloy by the corresponding standard.