scholarly journals The Comparison of Selected Methods of Cast Iron Spheroidization in Industrial Conditions

2012 ◽  
Vol 12 (2) ◽  
pp. 89-92 ◽  
Author(s):  
T. Válek ◽  
P. Šimon ◽  
L. Střílková
Keyword(s):  
Cast Iron ◽  
Production Quality ◽  
Ductile Cast Iron ◽  
Spheroidal Graphite ◽  
Cored Wire ◽  
Centrifugally Cast ◽  
Graphite Morphology ◽  
Graphite Cast Iron ◽  
Economic Balance ◽  
Nodular Graphite

The Comparison of Selected Methods of Cast Iron Spheroidization in Industrial Conditions Production of spheroidal graphite cast iron is today quite mastered technology. There are many methods achieving the nodular graphite morphology. Each of these methods have specific characteristics and requirements to technical support, properties and the type of applied modifier. Selection of the spheroidization method is dependent on foundry disposition, production character, economic balance, quality requirements, etc. In case of centrifugally casting the core, which fills body and neck of the roll, is created by ductile iron. Considering the sophisticated production of centrifugally cast rolls for hot rolling mills it is necessary to ensure a high reproducibility and reliability of ductile cast iron production quality in the bulk range of 9-18 t per tapping. These conditions are in the Roll Foundry in Vítkovicke Slevarny, spol. s r.o. provided and verified mastered overpour method and the newly injection of cored wire in the melt.

Effect of Strontium Addition in Graphite Morphology and Nodularization of Hypoeutectic Cast Iron

2020 ◽  
Vol 1000 ◽  
pp. 454-459
Author(s):  
Rahmadi ◽  
Deni Ferdian
Keyword(s):  
Cast Iron ◽  
Image Data ◽  
Optical Microscope ◽  
Spheroidal Graphite ◽  
Data Processing Software ◽  
Graphite Morphology ◽  
Spheroidal Graphite Cast Iron ◽  
Graphite Cast Iron ◽  
Molten Cast Iron ◽  
Nodular Graphite

Nodular graphite cast iron or known as spheroidal graphite cast iron structurally has a spherical graphite morphology with a matrix consisting of a ferrite-pearlite phase. In general, cast iron has a main alloy consisting of carbon and silicon where both elements have an influence on the potential of graphitization and castability. In this work, the influence of strontium (Sr) added to molten cast iron with a composition of 0, 0.04, 0.06 and 0.08 wt% to graphite morphology were studied. The sample obtained will be carried out a characterization process by observing macro and microstructures using optical microscope equipped with image data processing software that displays graphite fraction, size, form and nodularity. Analysis showed that Sr addition increase in nodularization of graphite from 19.6 % to 31.5% at 0.08 wt% Sr addition.

Influence of Ca-Ba and Sr Base Inoculants on Metallurgical and Mechanical Properties of Grey and Ductile Cast Irons

2018 ◽  
Author(s):  
Dhruv Patel ◽  
Devendra Parmar ◽  
Siddharthsinh Jadeja
Keyword(s):  
Mechanical Properties ◽  
Cast Iron ◽  
Uniform Distribution ◽  
Ductile Cast Iron ◽  
Grain Structure ◽  
Spheroidal Graphite ◽  
Primary Carbide ◽  
Cast Irons ◽  
Melt Temperature ◽  
Nodular Graphite

Microstructural adaptation of cast iron alloys by inoculation is a well-known practice to swell their mechanical properties. In foundries, several inoculants have been used to refine grain structure, and to obtain uniform distribution of graphite flakes. Inoculation is one of the most critical steps in cast iron production. The effectiveness of inoculants depends on melt temperature, method of addition, type of inoculants, and holding time. In this paper, the effect of Ca-based, Ba-based, Ca-Ba based and Sr-based inoculants on microstructure and tensile properties of grey cast iron IS-210 and spheroidal graphite iron IS-1862 is reported. Results showed both Ca and Ba based inoculants were effective in obtaining uniform distribution of flaky and nodular graphite in IS-210, and IS-1862 cast irons, respectively. But in a case of Sr-based inoculant were highly effective for increase the nodularity of SG cast iron as well as succeed supreme yield strength for both grey and ductile cast iron. The amounts of ferrite in the as-cast matrix are excess with controlled granulometry for elimination of primary carbide in Sr-based inoculant.

Research on Cored Wire Re-Sulfurization Injection for Compacted Graphite Cast Iron

2015 ◽  
Vol 727-728 ◽  
pp. 231-234
Author(s):  
Yu Shuang Feng ◽  
Ze Sheng Ji ◽  
He Sheng Wu
Keyword(s):  
Cast Iron ◽  
Automotive Industry ◽  
Ductile Cast Iron ◽  
Application Process ◽  
Cored Wire ◽  
Injection Speed ◽  
Compacted Graphite ◽  
Iron Castings ◽  
Graphite Cast Iron ◽  
Engineering Industries

To promote the application process of compacted graphite cast iron in non-automotive industry, cored wire re-sulfurization injection was developed for the production of compacted graphite cast iron. Firstly, ductile cast iron was produced by cored wire injection. Then, the effective final residual Mg level was reduced to the appropriate range for compacted graphite formation by feeding sulfidizing cored wire containing 99% S. In this paper, the influencing factors on percentage of compacted graphite were analysed, such as the final residual Mg level, cored wire injection speed. The results show that compacted graphite cast iron with less than 20% nodularity can be produced steadily on the condition of adopting the correct speed and the added sulfidizing cored wire in the range from 0.8m/t to 0.9m/t. Practice has proven that cored wire re-sulfurization injection would be most appropriate for jobbing foundries intending to manufacture compacted graphite cast iron castings for engineering industries.

The Effect of Magnesium to Sulfur Ratio on the Graphite Morphology of Graphite Cast Iron Produced at Differrent Section Thicknesses

2011 ◽  
Vol 383-390 ◽  
pp. 5880-5885
Author(s):  
Omar Elmabrouk ◽  
Osama M. Erfan ◽  
Ali Kalkanli
Keyword(s):  
Mechanical Properties ◽  
Cast Iron ◽  
Ductile Cast Iron ◽  
Flake Graphite ◽  
Factors Affecting ◽  
Compacted Graphite ◽  
Graphite Particles ◽  
Graphite Morphology ◽  
Graphite Cast Iron ◽  
Flake Graphite Cast Iron

This paper is concerned with the investigation of the effect of magnesium to sulfur ratio on the graphite morphology and estimation of the ranges of this ratio use to produce graphite cast iron at different section sections. The main factors affecting shape of graphite cast iron are the metallurgical structures and the section thicknesses. Cast iron of different shapes of graphite particles directly affect its thermo-mechanical properties. The nodular shape of these graphite particles such as in ductile cast iron improve its mechanical properties, on the other hand, when the shape of these graphite particles become elongated such as in flake graphite cast iron results in improving its thermal conductivity. In between, the worm-like shape of these graphite particles such as in compacted graphite cast iron, make this type of cast iron to have thermo-mechanical properties in between those of ductile and flake graphite cast iron. The different types of ductile , compacted and flake graphite cast iron were produced by means of plunger method at different section thicknesses and the effect of Mg/S ratio on these types of graphite particles was investigated and its range was established.

scholarly journals Influence of Austempering Temperatures on the Microstructure and Mechanical Properties of Austempered Ductile Cast Iron

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 967
Author(s):  
Regita Bendikiene ◽  
Antanas Ciuplys ◽  
Ramunas Cesnavicius ◽  
Audrius Jutas ◽  
Aliaksandr Bahdanovich ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cast Iron ◽  
Salt Bath ◽  
Ductile Cast Iron ◽  
Spheroidal Graphite ◽  
Xrd Diffraction ◽  
Microstructure And Mechanical Properties ◽  
Graphite Cast Iron ◽  
Austempering Temperature ◽  
Austempered Ductile Cast Iron

The influence of the austempering temperatures on the microstructure and mechanical properties of austempered ductile cast iron (ADI) was investigated. ADI is nodular graphite cast iron, which owing to higher strength and elongation, exceeds mechanical properties of conventional spheroidal graphite cast iron. Such a combination of properties is achieved by the heat treatment through austenitization, followed by austempering at different temperatures. The austenitization conditions were the same for all the samples: temperature 890 °C, duration 30 min, and quenching in a salt bath. The main focus of this research was on the influence of the austempering temperatures (270 °C, 300 °C, and 330 °C) on the microstructure evolution, elongation, toughness, and fatigue resistance of ADI modified by certain amounts of Ni, Cu, and Mo. The Vickers and Rockwell hardness decreased from 535.7 to 405.3 HV/1 (55.7 to 44.5 HRC) as the austempering temperature increased. Optical images showed the formation of graphite nodules and a matrix composed of ausferrite; the presence of these phases was confirmed by an XRD diffraction pattern. A fracture surface analysis revealed several types of the mechanisms: cleavage ductile, transgranular, and ductile dimple fracture. The stress-controlled mechanical fatigue experiments revealed that a 330 °C austempering temperature ensures the highest fatigue life of ADI.

Influence of Melting Conditions on Graphite Morphology in Spheroidal Graphite Cast Iron Using Ni-C Alloys

2010 ◽  
Vol 457 ◽  
pp. 37-42 ◽  
Author(s):  
Yuji Kato ◽  
Ying Zou ◽  
Hideo Nakae
Keyword(s):  
Cast Iron ◽  
Cooling Rate ◽  
High Purity ◽  
Holding Time ◽  
Spheroidal Graphite ◽  
Graphite Morphology ◽  
Spheroidal Graphite Cast Iron ◽  
Graphite Cast Iron ◽  
Group 2 ◽  
Group 1

The effects of the cooling rate, atmosphere and holding time on the graphite morphology of spheroidal graphite cast iron were studied using Ni-C alloys. Two groups of parent alloys were prepared using high purity materials, i.e., Group 1 containing the spheroidizing element of Ce, Mg or Ca, while in Group 2, S was added as an anti-spheroidizing element. For discussing the influence of the cooling rate on the graphite morphology, 0.5g of the Group 1 samples were melted and held for 15 minutes at 1673K in an Ar atmosphere, then cooled at 1000K/min or 20K/min. The results showed that perfect spheroidal graphite could not be confirmed, while irregular graphite appeared. The atmosphere was changed to Ar+3%H2 for preventing the oxidation, and the holding time was reduced to 10 minutes to prevent fading of the spheroidizing element. These results showed that the formation of spheroidal graphite was confirmed at the cooling rate of 1000K/min in both groups. Nevertheless, at the cooling rate of 20K/min, graphite morphology was only chunky or flake in both groups. In order to investigate which parameter is more important for the formation of spheroidal graphite, the atmosphere and the holding time were independently changed at the cooling rate of 1000K/min. It was found that the addition of the 3%H2 did not significantly affect the spheroidal graphite formation. Moreover, the holding times of 1min and 20min also did not significantly affect the spheroidal graphite area fraction in the Ni-C alloy, while they affected the ones containing the spheroidizing elements like Mg.

Microstructural Simulation of Solidification Process of Spheroidal-Graphite Cast Iron

2006 ◽  
Vol 73 (6) ◽  
pp. 977-983 ◽  
Author(s):  
Patricia M. Dardati ◽  
Luis A. Godoy ◽  
Diego J. Celentano
Keyword(s):  
Cast Iron ◽  
Solidification Process ◽  
Quantitative Agreement ◽  
Ductile Cast Iron ◽  
Spheroidal Graphite ◽  
Element Discretization ◽  
Spheroidal Graphite Cast Iron ◽  
Graphite Cast Iron ◽  
Macro Domain ◽  
Microstructural Behavior

This paper presents a new micro-macro approach for the thermo-microstructural behavior of the solidification process of an eutectic ductile cast iron. The thermal balance is written at a macroscopic level and can take into account both the structural component being cast and its mold. Models of nucleation and growth represent the evolution of the microstructure, following a multinodular solidification theory with independent nucleation of graphite and austenite and a dendritic growth of austenite. The resulting formulation is solved using a finite element discretization of the macro domain, in which the evolution of the microstructure is taken into account at the Gauss integration points. The quantitative agreement between experimental and computational values in terms of cooling curves is acceptable.

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