scholarly journals Solidification Chronology of the Metal Matrix and a Study of Conditions for Micropore Formation in Cast Irons Using EPMA and FTA

2018 ◽  
Vol 925 ◽  
pp. 436-443 ◽  
Author(s):  
Björn Domeij ◽  
Attila Diószegi
Keyword(s):  
Metal Matrix ◽  
Heat Dissipation ◽  
Freezing Point ◽  
Spheroidal Graphite ◽  
Cast Irons ◽  
Local Composition ◽  
Fourier Thermal Analysis ◽  
Solidification Kinetics ◽  
Mass Fractions ◽  
Late Deceleration

Microsegregation is intimately coupled with solidification, the development of microstructure, and involved in the formation of various casting defects. This paper demonstrates how the local composition of the metal matrix of graphitic cast irons, measured using quantitative electron microprobe analysis, can be used to determine its solidification chronology. The method is applied in combination with Fourier thermal analysis to investigate the formation of micropores in cast irons with varying proportions of compacted and spheroidal graphite produced by remelting. The results indicate that micropores formed at mass fractions of solid between 0.77 and 0.91, which corresponded to a stage of solidification when the temperature decline of the castings was large and increasing. In 4 out of the 5 castings, pores appear to have formed soon after the rate of solidification and heat dissipation had reached their maximum and were decreasing. While the freezing point depression due to build-up of microsegregation and the transition from compacted to spheroidal type growth of the eutectic both influencing solidification kinetics and the temperature evolution of the casting, the results did not indicate a clear relation to the observed late deceleration of solidification.

MEEHANITE GB300

Alloy Digest ◽  
2020 ◽  
Vol 69 (11) ◽  
Keyword(s):  
Thermal Conductivity ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Gray Cast Iron ◽  
High Strength ◽  
Heat Treating ◽  
Spheroidal Graphite ◽  
Cast Irons ◽  
Test Pieces ◽  
Temperature Performance

Abstract Meehanite GB300 is a pearlitic gray cast iron that has a minimum tensile strength of 300 MPa (44 ksi), when determined on test pieces machined from separately cast, 30 mm (1.2 in.) diameter test bars. This grade exhibits high strength while still maintaining good thermal conductivity and good machinability. It is generally used for applications where the thermal conductivity requirements preclude the use of other higher-strength materials, such as spheroidal graphite cast irons, which have inferior thermal properties. This datasheet provides information on physical properties, hardness, tensile properties, and compressive strength as well as fatigue. It also includes information on low and high temperature performance as well as heat treating, machining, and joining. Filing Code: CI-75. Producer or source: Meehanite Metal Corporation.

ISO 185/JL/350

Alloy Digest ◽  
2021 ◽  
Vol 70 (9) ◽  
Keyword(s):  
Thermal Conductivity ◽  
Tensile Strength ◽  
Cast Iron ◽  
Gray Cast Iron ◽  
High Strength ◽  
Heat Treating ◽  
Gray Cast ◽  
Spheroidal Graphite ◽  
Cast Irons ◽  
Test Pieces

Abstract ISO 185/JL/350 is a higher-tensile-strength gray cast iron that has a pearlitic matrix, and a tensile strength of 350–450 MPa (51–65 ksi), when determined on test pieces machined from separately cast, 30 mm (1.2 in.) diameter test bars. It provides a combination of high strength while still maintaining good thermal conductivity compared with other types of cast iron. This grade approaches the maximum tensile strength attainable in gray cast iron. Applications therefore tend to be confined to those where thermal conductivity requirements in service preclude the use of one of the other higher-strength materials such as spheroidal graphite cast irons, which have inferior thermal properties. This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on wear resistance as well as casting and heat treating. Filing Code: CI-85. Producer or source: International Organization for Standardization.

Semisolid Forging of Cast Iron Using Rapid Resistance Heating

2007 ◽  
Vol 561-565 ◽  
pp. 925-928 ◽  
Author(s):  
Seijiro Maki ◽  
Kazuhito Suzuki ◽  
Kenichiro Mori
Keyword(s):  
Cast Iron ◽  
Control Function ◽  
Electric Energy ◽  
Spheroidal Graphite ◽  
Pig Iron ◽  
Resistance Heating ◽  
Cast Irons ◽  
Ac Power ◽  
Spheroidal Graphite Cast Iron ◽  
Graphite Cast Iron

Feasibility of semisolid forging of cast iron using rapid resistance heating was experimentally investigated. Gray pig iron FC250 and spheroidal graphite cast iron FCD600, whose carbon equivalents are both 4.3% in mass, were used for the experiments. Since these cast irons have a narrow semisolid temperature range, an AC power supply with an input electric energy control function was used. In this study, the resistance heating characteristics of the cast irons were firstly examined, and then their semisolid forging experiments were conducted. In the forging experiments, the conditions of the forgings such as microstructures and hardness properties were examined, and the feasibility of the semisolid forging of cast iron using resistance heating was discussed. As a result, it was found that the method presented here is highly feasible.

scholarly journals Impact Properties of Austempered Spheroidal Graphite Cast Irons

2017 ◽  
Vol 08 (13) ◽  
pp. 948-958 ◽  
Author(s):  
Tohru Nobuki ◽  
Minoru Hatate ◽  
Toshio Shiota
Keyword(s):  
Spheroidal Graphite ◽  
Cast Irons ◽  
Impact Properties

scholarly journals Ausferritic (bainitic) cast iron: Harmonization of international standard ISO 17804 in application to the conditions of Belarus

2021 ◽  
pp. 56-72
Author(s):  
A. I. Pokrovskii ◽  
B. B. Khina ◽  
O. A. Tolkacheva
Keyword(s):  
Tensile Strength ◽  
Cast Iron ◽  
Ductile Iron ◽  
High Strength ◽  
State Committee ◽  
Spheroidal Graphite ◽  
Cast Irons ◽  
International Standard ◽  
Industrial Enterprises ◽  
State Organizations

The experience of the Physico-technical Institute (PhTI) of the National Acdemy of Sciences of Belarus in the harmonization of international standard ISO 17804 (Founding – Ausferritic spheroidal graphite cast irons – Classification) and development of the Belorussian analogue STB ISO is described. The reasons for the choice of austempered ductile iron (ADI) as an object for standard harmonization are presented: it is the most promising cast iron in comparison with gray and classical ductile iron. The work procedure on harmonization is described: how to include the task into the State Plan on standardization, specificity of translation of the text, peculiarities of with state organizations responsible for approbation of standards such as Belorussian Institute for Standardization and Certification (BelGISS) and State Committee on Standards (Gosstandart), writing a summary of external reviews, working with critical comments from potential users. It is outlined that any foreign standard does not exists independently but is closely connected with at least 10 to 20 other standards. Thus, harmonization necessitates coordination with other standards and sometimes even with handbooks by adding annexes to the main text. The importance of a proper choice of the standard status is outlined: identical (ID) or modified (MOD). Developing an identical standard is prestigious but difficult because is requires harmonization of all the referenced standards, which is a very labor-consuming procedure. It is argued that the most suitable is ‘intermediate’ variant: adopting the authentic text of the international standard (in high-quality translation) but with annexes reflecting national specificity in this area. As a result, a harmonized standard is developed which, for the first time in Belarus, standardize the tensile strength of 800 MPa in combination with the elongation of 10 % and the tensile strength of 1400 MPa in combination with the elongation of 1 % for cast irons.The annual demand for ADI in Belarus is estimated as about 10,000 ton. It is shown that in Belarus, where about 60 industrial enterprises have a foundry and almost every engineering plant has a heat-treatment shop, austempered ductile cast (ADI), which features a high strength, can successfully compete with rolled steel in certain applications.

Recent Developments in the Ironfounding Industry

1972 ◽  
Vol 186 (1) ◽  
pp. 149-168
Author(s):  
H. Morrogh
Keyword(s):  
Capital Investment ◽  
Production Efficiency ◽  
Cumulative Effect ◽  
Spheroidal Graphite ◽  
Mechanical Equipment ◽  
Cast Irons ◽  
Delivery Times ◽  
Iron Castings ◽  
Wide Range ◽  
Recent Developments

Iron castings are in extensive use throughout engineering construction and are available in a wide range of properties, casting size and complexity. Ironfounding is in part associated with a particular industry—the ironfounding industry—and is in part a production engineering technique adopted by firms, their designers and engineers, on the basis of its process and product merits compared with those of other techniques. The changing pattern of manufacture and competition from other techniques is having important influences on the structure and capacity of industry producing iron castings. Additionally, the repeated cycles of business recession may result in the disappearance of the facilities for the production of certain types of foundry product. Although most recent developments in ironfounding are a continuation of trends which could be discerned or forecast a long time ago, the cumulative effect of these changes has been to revolutionize completely some aspects of the process of iron casting. The range of cast irons has been somewhat increased in recent years by addition to the variety of spheroidal graphite (s.g.) irons, malleable irons and alloy cast irons available. Most of the recent developments in ironfounding have, however, been concerned with improving production efficiency and the introduction of new melting, moulding and coremaking processes, enabling the ironfounder to provide the engineer and designer with a better service—maintaining prices at low level, improving dimensional accuracy and casting soundness with reduced delivery times. This has been achieved by the increased use of scrap made possible by developments in melting furnaces and molten metal treatment, by the introduction of new and improved moulding machinery and by the adoption of new methods of bonding sand used for moulds and cores, replacing many traditional techniques. These changes have had their influence equally in the large, highly mechanized mass-production foundries and in the jobbing foundries catering for short run work. An ironfoundry is an extremely exacting environment for mechanical equipment and for all control engineering. For this reason automatic moulding and other foundry plant need special design and robust construction. Most mechanized foundry plant of an automatic character represents a high capital investment which must run for long periods without breakdown, requiring long orders and work of a repetitive character.

3D characterization of structure and micro-porosity in two cast irons with spheroidal graphite

2019 ◽  
Vol 158 ◽  
pp. 109991 ◽  
Author(s):  
Simon N. Lekakh ◽  
Xueliang Zhang ◽  
Wesley Tucker ◽  
Hyoung K. Lee ◽  
Tara Selly ◽  
...  
Keyword(s):  
Spheroidal Graphite ◽  
Cast Irons

scholarly journals Redistribution and Effect of Various Elements on the Morphology of Primary Graphite in Cast Iron

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
J. Lacaze ◽  
N. Valle ◽  
K. Theuwissen ◽  
J. Sertucha ◽  
B. El Adib ◽  
...  
Keyword(s):  
Secondary Ion Mass Spectrometry ◽  
Spheroidal Graphite ◽  
Metallic Elements ◽  
Controlled Cooling ◽  
Cast Irons ◽  
Bulk Graphite ◽  
Distribution Of Elements ◽  
Graphite Growth ◽  
Secondary Ion

It has been shown repeatedly that many elements present as traces or at low level can affect graphite shape in cast irons. As part of a long term project aimed at clarifying the growth and the alteration of spheroidal graphite, a study on the effect of a few elements (Cu, Sn, Sb, and Ti) on primary graphite growth was undertaken and analysed with reference to an alloy without any such additions. This work was performed by remelting alloys in graphite crucibles thus saturating the melt in carbon and enabling primary graphite to grow by controlled cooling of the melt above the eutectic temperature. Primary graphite growth in the reference alloy was observed to be lamellar, while the added elements were found to affect bulk graphite and to modify its outer shape, with Sb leading eventually to rounded agglomerates together with wavy lamellae. Secondary ion mass spectrometry was used to analyze the distribution of elements, and no build-up of trace elements at the graphite surface could be observed. Instead, it is established that the perturbation of bulk graphite is associated with inhomogeneous distribution of metallic elements inside graphite precipitates.

scholarly journals UHVEM observation for the dual structure in spheroidal graphite of cast irons

2016 ◽  
pp. 285-286
Author(s):  
Hidefumi Maeda ◽  
Kanako Inoue ◽  
Akira Sugiyama ◽  
Hidehiro Yasuda
Keyword(s):  
Spheroidal Graphite ◽  
Cast Irons ◽  
Dual Structure
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