Influence of Metallurgical Treatment on Properties of Ductile Cast Iron GJS 400-18 LT

2014 ◽  
Vol 635 ◽  
pp. 177-181
Author(s):  
Marianna Bartošová ◽  
Alena Pribulová ◽  
Jozef Bibko ◽  
Peter Futáš

Cast iron with spheroidal graphite is a very good constructional material. Production of castings from standard kinds of nodular cast irons is quite good managed, but manufacturing of mark GJS 400-18 LT with excelent strength and plastic properties by minus temperatures is complicated, because it reacts very sensitively on the changing of melting conditions and metallugical treatment. The contribution is focused on an observation of changing of structure and mechanical properties by different ways of metallurgical treatment. In operating conditions of foundry three series of melts were made. From every melt the mould with testing pieces „Y“ with dimensions 25 x 40 x 140 mm was poured. Tensile test, impact test and metalographic analyse were realized on the test samples.

Author(s):  
Dhruv Patel ◽  
Devendra Parmar ◽  
Siddharthsinh Jadeja

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.


2020 ◽  
Vol 998 ◽  
pp. 42-47
Author(s):  
Alena Pribulová ◽  
Peter Futaš ◽  
Marcela Pokusova

Worldwide production of ductile iron castings reached in year 2017 26,428,148 metric tons, which is 34% of the total weight of all castings made from cast iron. The most significant increase in ductile iron castings was recorded in Slovakia, up to 78.6%. Castings from ductile iron have a very huge utilization thanks their very good foundry and mechanical properties. The current economic situation in all industries forces entrepreneurs and producers to rationalize production and reduce production costs, with a worldwide trend to increase the share of steel scrap, a technology for the production of ductile cast iron. The paper describes the results of research focused on the effect of charge composition, mainly the share of scrap steel on the final properties and structure of ductile iron EN-GJS-500-7 under the operating conditions of foundry. Six melts with different charge composition were made. The samples from all melts were taken and chemical analysis, microstructure analysis and testing on mechanical properties were made on them. The mechanical properties of produced globular cast irons were according with the relevant standard. It is important to mention that there has been a significant increase in strength characteristics in melts in which the carbon content exceeded 4% (CE = 4.7 and 4.8%, respectively).


Author(s):  
A. P. Kren ◽  
V. A. Rudnitsky ◽  
G. A. Lantsman ◽  
M. N. Delendik ◽  
N. V. Zinkevich ◽  
...  

The possibility of the application of impact microindentation method for testing the physic and mechanical properties of cast iron using the IFMH-C instrument developed at the Institute of applied physics of the National Academy of Sciences of Belarus was tested. It was established that the method and the instrument allow to estimate such parameters as Brinell hardness in the range of 100–500 HB, elastic modulus from 40 to 200 MPa, as well as to determine the tensile strength of the flake and spheroidal graphite cast irons. The possibility of using the instrument for non-destructive test directly of parts and products in the manufacturing environments is shown.


2010 ◽  
Vol 457 ◽  
pp. 380-385
Author(s):  
Minoru Hatate ◽  
Tohru Nobuki ◽  
Shoji Kiguchi ◽  
Kazumichi Shimizu

Low thermal expansion ductile cast iron is expected to become a new structural material with high dimensional stability against temperature change. We tried to develop a new low thermal expansion ductile cast iron by means of adding C and Si to Superinver alloy. In this study we prepared four kinds of ductile cast irons whose Co contents vary from 0% to 12 %, and investigated about the effects of Co content and solution-treatments on several main characteristics such as coefficient of thermal expansion and mechanical properties. The results obtained are as follows: With increase of Co content the amount of martensite increases but this martensite can be inverse-transformed to austenite totally or greatly by solution-treatment followed with water-quenching. In the case of Co content less than some 9 % the ability of relatively larger plastic deformation can be expected in inverse-transformed austenite.


2015 ◽  
Vol 15 (4) ◽  
pp. 69-74 ◽  
Author(s):  
B. Skrbek ◽  
K. Policar

Abstract Topic of this work is to compare metalurgy of cast irons poured into sand moulds and into shell molds at IEG Jihlava company and from it following differencies in structures of thin- and thick-walled castings. This work is dealing with investigation and experimental measurement on surfaces and sections suitable thin- and thick-walled investment castings at IEG Jihlava. Cast irons with flake graphite (grey cast iron) and cast irons with spheroidal graphite (ductile cast iron). Both mechanical and physical properties are determined using calculations from as measured values of wall thicknesses L and Lu, Vickers hardness and remanent magnetism. Measurement results are discussed, findings are formulated and methods for castings metallurgical quality improvement are recommended finally.


10.30544/77 ◽  
2015 ◽  
Vol 21 (3) ◽  
pp. 155-166
Author(s):  
Abhijit Malage ◽  
Priti P. Rege ◽  
Manoj J. Rathod

Ductile cast iron is preferred as nodular iron or spheroidal graphite iron. Ductile cast iron contains graphite in form of discrete nodules and matrix of ferrite and perlite. In order to determine the mechanical properties, one needs to determine volume of phases in matrix and nodularity in the microstructure of metal sample. Manual methods available for this, are time consuming and accuracy depends on expertize. The paper proposes a novel method for automatic quantitative analysis of microstructure of Ferritic Pearlitic Ductile Iron which calculates volume of phases and nodularity of that sample. This gives results within a very short time (approximately 5 sec) with 98% accuracy for volume phases of matrices and 90% of accuracy for nodule detection and analysis which are in the range of standard specified for SG 500/7 and validated by metallurgist.


2021 ◽  
Vol 39 ◽  
pp. 9-19
Author(s):  
Özer Özdemir ◽  
Selim Gürgen ◽  
Melih Cemal Kuşhan

Ultrasonic inspection is a well-known method in non-destructive testing. Based on the changes in the ultrasonic sound speed, tested materials are evaluated in terms of internal defects. In addition to flaw detection, ultrasonic testing is used in the material characterization of ductile cast iron. Graphite shape detection has been widely investigated by ultrasonic inspection in literature. However, most of the measurements has been conducted at single frequencies. In this work, three different nodulizer included casting operations were carried out to produce ductile cast irons having various graphite morphologies. A wide frequency range of 1.25-10 MHz was selected in the ultrasonic inspection. In addition to graphite morphology analyses, the relationship between ultrasonic sound speed and mechanical properties was studied. In the mechanical analyses, hardness and tensile testing properties were investigated for the specimens. From the results, ultrasonic sound speed exhibits a considerable dependency to the graphite morphology. In addition to a good graphite detection capability, ultrasonic inspection exhibits promising results for predicting the mechanical properties such as hardness, elastic modulus, yield strength and tensile strength. It is also found that there is a slight increase in the ultrasonic sound speed by increasing the frequency, although sound speed is independent from this parameter.


2018 ◽  
pp. 105-140
Author(s):  
José Antonio Pero-Sanz Elorz ◽  
Daniel Fernández González ◽  
Luis Felipe Verdeja

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 967
Author(s):  
Regita Bendikiene ◽  
Antanas Ciuplys ◽  
Ramunas Cesnavicius ◽  
Audrius Jutas ◽  
Aliaksandr Bahdanovich ◽  
...  

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.


2012 ◽  
Vol 12 (3) ◽  
pp. 43-48
Author(s):  
A. Hanus ◽  
P. Hanusová

Abstract Increasing demands on the utility properties of materials used for castings have led to the production of cast iron with a modified shape of graphite, where the required properties are achieved by a change in graphite shape, its size and layout, and a change in the basic structure of the metal. This paper is focused on the continuous method of producing spheroidal graphite FLOTRET. In the introductory section is summarized the theoretical foundations of the secondary treatment of cast irons, especially the FLOTRET flow method, describes the advantages and disadvantages of the method. The practical part is divided into laboratory and operational tests. Laboratory experiments were conducted on a laboratory-type modifier FLOTRET chamber, which was designed and hydraulically optimized. Experiments were focused on the effects of pressure altitude and amount of modifier on the residual values of magnesium, as conditions for a successful modification. The method was tested in two foundries under operating conditions and in one of them was observed a long-term modification process.


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