Optimizing the Gating System for Steel Castings

Jezierski, J.; Dojka, Rafał; Janerka, K.

doi:10.3390/met8040266

Cited by 25 publications

(14 citation statements)

References 29 publications

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“…The simulations and experimental casting confirmed the effectiveness of the foam filter and vortex element on the melt velocity which corresponds with previous works [19,28,29].…”

supporting

confidence: 88%

Numerical Simulation and Experimental Validation of Melt Flow in the Naturally Pressurized Gating System

2021

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The main problem during the production of castings from aluminium alloys is the presence of the reoxidation, which negatively affects the final casting quality. Liquid metal surface reacts with the surrounding atmosphere and oxide layer of Al2O3 is formed on its surface. The problem occurs when the oxide layer is entrained to the internal volume of the melt by turbulence and double oxide layers are formed, also known as “bifilms”. Its formation is related to the melt velocity and gating system design. In paper, naturally pressurized gating system was calculated and designed. Effect of the filter media and vortex element on the melt velocity, amount of oxides, mechanical properties, and porosity were observed. Designs with 10 ppi and 20 ppi foam filters and vortex element were compared with design without filters to prove the positive (or negative) effect of filter media on melt velocity and thus on final casting quality. The melt velocity and amount of oxides were observed with the aid of simulation software. Mechanical properties, quantity of pores, bifilm index and EDX analysis were evaluated after experimental casts. It was proven that by using 20 ppi foam filter in combination with vortex element, the best results were achieved.

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“…The simulations and experimental casting confirmed the effectiveness of the foam filter and vortex element on the melt velocity which corresponds with previous works [19,28,29].…”

supporting

confidence: 88%

Numerical Simulation and Experimental Validation of Melt Flow in the Naturally Pressurized Gating System

2021

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“…Nevertheless, if manufacturers decide to use high inoculant levels to create crystallization underlays and hard phases to increase the wear resistance, they should consider quality casting technology. The design of a proper gating system could help to eliminate bifilm defects [ 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ], which generate TiC agglomeration. This may improve the TiC distribution, providing more even wear properties in the entire casting.…”

Section: Resultsmentioning

confidence: 99%

Bifilm Defects in Ti-Inoculated Chromium White Cast Iron

Dojka

Stawarz

2020

Materials

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In recent years, white chromium cast iron has gained a well-settled position among wear-resistant materials. In recent times, chromium cast iron samples containing titanium have attracted attention. In cast iron samples, titanium combines with carbon and forms TiC particles, which may be form a crystallization underlay for eutectic M7C3 carbides and austenite. Accordingly, the inoculation process occurring in the crystallizing alloy should result in the proper, regular distribution of fine eutectic chromium carbides in the austenitic matrix. The presented research was conducted on 20% Cr hypoeutectic white cast iron with the addition of 0.5, 1, and 2% of Ti. Ti inoculation and the presence of TiC allowed for superior wear properties to be obtained. However, the conducted study revealed a significant decrease in the impact strength of examined alloys, especially for the cast iron samples with a high amount of Ti, in which the TiC compounds agglomerated. Titanium compounds accumulate in clusters and their distribution is irregular. Most of the TiC compounds were transported by the crystallization front into the center of the castings, where micropores were formed, meaning they were no longer effective crystallization underlays. In the authors’ opinion, the agglomerate formation is strictly connected with the appearance of bifilm defects in the casting microstructure. The conducted research shows how an incorrect volume of an additive may have negative influences on the properties of the casting. This is a vital issue not only from a technological point of view, but also for economic reasons.

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“…Continuing with the design of the metal feeding system in a near-net-shape casting process, the article presents an attempt to optimize a gating system for a steel casting. The approach adopted in the study by Jezierski et al [6] is based on John Campbell's theory and presents the original results of computer modeling of a typical gating system and an optimized system for cast steel components. The current state-of-the-art in a foundry was compared with several proposals for an optimized gating system.…”

Section: Contributions To the Special Issuementioning

confidence: 99%