scholarly journals Automatic quantitative analysis of microstructure of ductile cast iron using digital image processing

10.30544/77 ◽  
2015 ◽  
Vol 21 (3) ◽  
pp. 155-166
Author(s):  
Abhijit Malage ◽  
Priti P. Rege ◽  
Manoj J. Rathod
Keyword(s):  
Mechanical Properties ◽  
Cast Iron ◽  
Quantitative Analysis ◽  
Ductile Cast Iron ◽  
Spheroidal Graphite ◽  
Metal Sample ◽  
Nodule Detection ◽  
Novel Method ◽  
Manual Methods ◽  
Short Time

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.

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.

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 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
Keyword(s):  
Mechanical Properties ◽  
Cast Iron ◽  
Impact Test ◽  
Constructional Material ◽  
Ductile Cast Iron ◽  
Operating Conditions ◽  
Spheroidal Graphite ◽  
Cast Irons ◽  
Plastic Properties ◽  
Test Impact

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.

scholarly journals Microstructure Image Analysis for Estimating Mechanical Properties of Ductile Cast Iron

2014 ◽  
Vol 107 (17) ◽  
pp. 32-35 ◽  
Author(s):  
P. S.Hiremath ◽  
Anita Sadashivappa ◽  
Prakash Pattan
Keyword(s):  
Mechanical Properties ◽  
Image Analysis ◽  
Cast Iron ◽  
Ductile Cast Iron

scholarly journals Revisiting Models for Spheroidal Graphite Growth

2018 ◽  
Vol 925 ◽  
pp. 118-124 ◽  
Author(s):  
Mathias Karsten Bjerre ◽  
Mohammed Azeem ◽  
Peter D. Lee ◽  
Jesper Henri Hattel ◽  
Niels Skat Tiedje
Keyword(s):  
Growth Rate ◽  
Cast Iron ◽  
Numerical Model ◽  
Final Stage ◽  
Nucleation And Growth ◽  
Ductile Cast Iron ◽  
Spheroidal Graphite ◽  
Microstructure Formation ◽  
X Ray ◽  
Graphite Growth

Recent experiments resolved nucleation and growth of graphite during solidification of ductile cast iron in 4D using synchrotron X-ray tomography. A numerical model for microstructure formation during solidification is compared with the experiments. Despite very good overall agreement between observations of spheroidal graphite growth and model results, significant deviations exist towards the end of solidification. We use the experimental observations to analyse the relation between graphite growth rate and the state of the particle neighbourhood to pinpoint possible links between growth rate of individual graphite spheres and the overall solidification state. With this insight we revisit existing models for growth of spheroidal graphite and discuss possible modifications in order to correctly describe the critical final stage of solidification.

TEM Observation of Spheroidal Graphite in Ductile Cast Iron

PRICM ◽  
2013 ◽  
pp. 3459-3464
Author(s):  
Takamichi Hara ◽  
Takahiro Kitagawa ◽  
Susumu Ikeno ◽  
Seiji Saikawa ◽  
Kiyoshi Terayama ◽  
...  
Keyword(s):  
Cast Iron ◽  
Ductile Cast Iron ◽  
Spheroidal Graphite
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