Simultaneous thermal and contraction / expansion curves analysis for solidification control of cast irons

Abstract

T he final control of the iron castings' quality involves different techniques, including chemical analysis, microstructure evaluation, physical and mechanical properties measurements, castings' surface parameters and casting soundness control, etc. It is important to forecast the final castings' characteristics before mould filling, by iron melt solidification control, applying techniques able to illustrate the eutectic undercooling values referring to the stable and metastable equilibrium temperatures, carbide or graphite formation tendency, a specific graphite morphology occurrence, metal matrix make-up, shrinkage and microshrinkage sensitivity, etc.Thermal (cooling curve) analysis has a wide application in the worldwide foundry industry to quickly control the solidification behaviour of foundry metallic alloys, especially for cast irons and non-ferrous alloys. At first, cooling curve analysis (CCA) *Iulian RiposanBorn in 1948, Ph.D, Professor. His research interests mainly focus on processing and complex characterization of lamellar, nodular, compacted/vermicular and coral graphite irons, austempered cast irons with lamellar, nodular, compacted or coral graphite, cast iron matrix composites, cupola and electric furnaces operations. To date, he has published more than 300 technical papers and 3 technical books, and holds 35 patents. He is the honorary member of Technical Sciences Academy of Romania, the Past President of Romanian Foundry Technical Association (ATTR) (1996 -2014), and an international member of American Foundry Society.

Investigate Temperature Preheating on the Chill Plate to Identify Surface Characteristic on the Ductile Iron by Sand Casting

“…Figure 5 show that the microstructure formation on specimen S4 is average and consists of a fully ferritic-matrix microstructure. Therefore, with the rapid cooling process, eutectic carbide formation and a microstructure containing cementite, ferrite, and pearlite are very uniform and compact on the surface area, as explained by Riposan L. et al [25] that the graphite carbide structure is formed at the end of the solidification step in the ductile iron casting process [35,36]. This occurs due to the rapid cooling of the interface through contraction between the cast liquid and the mold wall.…”

“…As for research from Shi, Z et al, using Fe-Cr-C as a hardfacing alloy then doped with Ce elements to increase the ductility and toughness of materials, but it still did not increase the high hardness on the surface [24]. Also, the element chromium is commonly used to bond preferentially to other elements to increase the hardness of the material [25,26]. Therefore, based on these reasons, the authors tried to perform surface hardening of the martensitic ductile cast iron material using the chilled casting method.…”

Application of Alloyed Cast Iron to Increase the Durability of Products of the Mining and Metallurgical Industry

“…The analysis of the main phases of cast iron: titanium carbide, phosphide eutectic and perlite matrix was performed using microstructure analysis [3]. Working out the optimal chemical composition it is necessary to try to obtain a favorable microstructure of cast iron for each specific case [3][4][5][6][7][8][9][10]. The naturally alloyed cast iron was found to have all the characteristics necessary to increase the service life of wear-resistant and heat-resistant products: high strength and wear resistance, and in the presence of phosphide eutectic, also good fluidity.…”

Experimental assessment of the gray cast iron production by inoculant injection

“…So, inoculants are added to produce heterogeneous nucleation of these graphite flakes and obtain the desired distribution. Improving manufacturing processes for cast iron is always needed and many gray iron studies focused on theories of graphite lamellar nucleation [7,8], pre-inoculation treatments [8,9], microstructure and mechanical properties [10][11][12], and inoculation fading effect [13,14] have been widely investigated but, few studies have been focused on the inoculant addition method. There are two main methods of inoculation: ladle and late inoculation.…”