Thermal Analysis to Optimize and Control the Cast Iron Solidification Process

The cooling curve and its derivatives display patterns that can be used to predict the characteristics of a cast iron. The effects of melting, superheating and holding in an acid lined coreless induction furnace were explored, as they affect the role of preconditioning and / or inoculation to restore solidification with low eutectic undercooling. Increased chill (iron carbides amount) in the experimental irons correlates well with certain thermal analysis parameters, such as the degree of eutectic undercooling. Preconditioning of the molten base iron before tapping led to improved solidification parameters in both untreated and inoculated irons as measured by the most significant thermal analysis cooling curve events. A double treatment incorporating preconditioning with inoculation improved the thermal analysis parameters, and consequently, the quality of the cast iron. If standard Ca-FeSi alloys do not have sufficient inoculation potential, the addition of the inoculant enhancing alloy (S, O and oxy-sulphides forming elements) will greatly enhance inoculation, well illustrated by changes to the thermal analysis parameters. A newly defined Inoculation Specific Factor [inoculation effect / inoculant consumption which led to that beneficial effect ratio] of different alloys is illustrated by thermal analysis, with good correlation with microstructural characteristics.

Manufacturing of Ferritic Low-Silicon and Molybdenum Ductile Cast Iron with the Innovative 2PE- 9 Technique

The use of two cored wire injection methods (2PE- 9) and the unique application of a drum ladle as a treatment, transport and casting one, instead of a vertical treatment ladle are presented. Optimization parameters, like: length of nodulariser wire, treatment and pouring temperature have been shown. The influence of various treatment temperatures on magnesium recovery is demonstrated. The typical microstructure, mechanical properties and cost calculation of the ferritic ductile cast iron (type SiMo - EN-GJS-SiMo40-6 Grade) production according to EN 16124:2011 (E) are presented. Injection of two Ø 9 mm as well wires; cored in FeSi + Mg nodulariser mixture and inoculant master alloy into a drum ladle is a treatment method that can be used for the production of ferritic ductile cast iron (SiMo) melted in a coreless induction furnace.

Using Cored Wire Injection Method in the Production of Austenitic High Ni-Alloyed Ductile Iron Castings

Below are described results of the analysis concerning the use of two cored wire injection method (2PE- 9) and the unique application of a drum ladle as a treatment, transport and casting one, instead of a vertical treatment ladle. Parameter optimization, like: length of nodulariser wire, residual magnesium content, treatment and pouring temperature have been shown. Influence of various treatment temperatures, magnesium-cored wire velocities (Mg-treatment times) and weights of molten alloy on magnesium recovery are demonstrated. Moreover, graphite nodule content in relation to different raw materials in the charge mix are presented. Typical microstructure, mechanical properties and treatment costs are given as well. Using specific industrial conditions for tests and optimal, low scrap production of austenitic nodular cast iron (EN-GJSA-XNiSiCr35-5-2 Grade, according with EN 13835), makes this innovative method very credible. Injection of two Ø 9 mm wires; cored in FeSi + Mg nodulariser mixture and inoculant master alloy into a drum ladle is a treatment method that can be used for the production of ductile iron melted in a coreless induction furnace.

Using Cored Wires Injection 2PE-9 Method in the Production of Ferritic Si-Mo Ductile Iron Castings

The results of studies on the use of modern two cored wires injection method for production of ferritic nodular cast iron (ductile iron) with use of unique implementation of drum ladle as a treatment / transport and casting ladle instead vertical treatment ladle was described. The injection of length of Ø 9mm wires, cored: in FeSi + Mg nodulariser mixture and inoculant master alloy is a treatment method which can be used to produce iron melted in coreless induction furnace. This paper describes the results and analysis of using this method for optimal production of ductile iron under specific industrial conditions. It means, that length of nodulariser wire plus treatment and pouring temperatures were optimized. In this case, was taken ductile iron with material designation: EN-GJS-SiMo40-6 Grade according EN 16124:2010 E. Microstructure of great number of trials was controlled on internally used sample which has been correlated with standard sample before. The paper presents typical ferritic metallic matrix and nodular graphite. Additionally, mechanical properties were checked in some experiments. Mean values of magnesium recovery and cost of this new method from optimized process parameters were calculated as well.

The turbulent recirculating flow field in a coreless induction furnace, a comparison of theoretical predictions with measurements

A mathematical representation has been developed for the electromagnetic force field and the fluid-flow field in a coreless induction furnace. The fluid flow field was represented by writing the axisymmetric turbulent Navier–Stokes equations, containing the electromagnetic body-force term. The electromagnetic body force field was calculated by using a technique of mutual inductances. The k-ε model was employed for evaluating the turbulent viscosity, and the resultant differential equations were solved numerically.The theoretically predicted velocity fields were in reasonably good agreement with the experimental measurements reported by Hunt & Moore; furthermore, the agreement regarding the turbulence intensities was essentially quantitative. These results indicate the k-ε model does provide a good engineering representation of the turbulent recirculating flows occurring in induction furnaces. At this stage it is not clear whether the discrepancies between measurements and the predictions, which were not very great in any case, are attributable either to the model or to the measurement techniques employed.