scholarly journals Galvanic Corrosion of Ductile Cast Iron Coupled with Different Alloys in Synthetic Domestic Waste Water

2019 ◽  
Vol 70 (2) ◽  
pp. 506-511 ◽  
Author(s):  
Cristian Savin ◽  
Carmen Nejneru ◽  
Manuela Cristina Perju ◽  
Costica Bejinariu ◽  
Diana Burduhos-Nergis ◽  
...  
Keyword(s):  
Waste Water ◽  
Cast Iron ◽  
Gray Cast Iron ◽  
Galvanic Corrosion ◽  
Nodular Cast Iron ◽  
Ductile Cast Iron ◽  
Aluminum Bronze ◽  
Metallic Materials ◽  
Low Alloy Steel ◽  
Domestic Waste

Waste water is an aggressive environment for transport pumps to treatment plants. The pumps used are generally, immersion pumps and are made of various elements like, rotor, stator, housing, screws, flanges, springs, seals, etc. The construction elements of the pumps are made of various metallic materials, such as nodular cast iron, gray cast iron, low alloy steel, stainless steel, aluminum, bronze, brass, copper, etc. When immersed in waste water, the metals form galvanic series. The paper presents the galvanic corrosion analysis of the above-mentioned metals in case the corrosive environment is waste water with various compositions.

scholarly journals Galvanic Corrosion Behaviour of Phosphate Nodular Cast Iron in Different Types of Residual Waters and Couplings

2019 ◽  
Vol 70 (10) ◽  
pp. 3597-3602 ◽  
Author(s):  
Carmen Nejneru ◽  
Manuela Cristina Perju ◽  
Dumitru Doru Burduhos Nergis ◽  
Andrei Victor Sandu ◽  
Costica Bejinariu
Keyword(s):  
Cast Iron ◽  
Corrosion Behaviour ◽  
Galvanic Corrosion ◽  
Nodular Cast Iron ◽  
Low Alloy Steel ◽  
High Chemical ◽  
Different Types ◽  
Grey Cast ◽  
Main Components ◽  
Galvanic Corrosion Behaviour

The aim of this paper is to analyze the corrosion process that occurs in galvanic couplings of different alloys. The study focuses on materials that can come into contact in submersible pumps used by water treatment plants. Because, the rotor, one of the pump main components must possess high chemical and mechanical properties, nodular cast iron is usually used. Therefore, this is exposed in the same environment with different types of materials, such as aluminum, copper, bronze, grey cast iron, low alloy steel or stainless steel from which other components are made. The tests have been performed in three types of residual waters with neutral, acidic and basic pH. According to this study, the nodular cast iron galvanic corrosion resistance is highly improved by the phosphate layer deposited on its surface.

scholarly journals The Influence of Different Assist Gases on Ductile Cast Iron Cutting by CO2 Laser

2017 ◽  
Vol 17 (4) ◽  
pp. 109-114 ◽  
Author(s):  
J. Meško ◽  
R. Nigrovič ◽  
A. Zrak
Keyword(s):  
Cast Iron ◽  
Laser Cutting ◽  
Roughness Parameter ◽  
Cutting Speed ◽  
Nodular Cast Iron ◽  
Ductile Cast Iron ◽  
Engineering Practice ◽  
Technological Parameters ◽  
The Stability

Abstract This article deals with the technology and principles of the laser cutting of ductile cast iron. The properties of the CO2 laser beam, input parameters of the laser cutting, assist gases, the interaction of cut material and the stability of cutting process are described. The commonly used material (nodular cast iron - share of about 25% of all castings on the market) and the method of the laser cutting of that material, including the technological parameters that influence the cutting edge, are characterized. Next, the application and use of this method in mechanical engineering practice is described, focusing on fixing and renovation of mechanical components such as removing the inflow gate from castings with the desired quality of the cut, without the further using of the chip machining technology. Experimental samples from the nodular cast iron were created by using different technological parameters of laser cutting. The heat affected zone (HAZ), its width, microstructure and roughness parameter Pt was monitored on the experimental samples (of thickness t = 13 mm). The technological parameters that were varied during the experiments included the type of assist gases (N2 and O2), to be more specific the ratio of gases, and the cutting speed, which ranged from 1.6 m/min to 0.32 m/min. Both parameters were changed until the desired properties were achieved.

Microstructure Observations of Graphite in Gray Cast Iron Using TEM

2016 ◽  
Vol 879 ◽  
pp. 1911-1914
Author(s):  
Makoto Takezawa ◽  
Seung Won Lee ◽  
Susumu Ikeno ◽  
Kenji Matsuda
Keyword(s):  
Cast Iron ◽  
Cross Section ◽  
Focused Ion Beam ◽  
Gray Cast Iron ◽  
Ion Beam ◽  
Iron Alloy ◽  
Ductile Cast Iron ◽  
Gray Cast ◽  
Formation Mechanisms ◽  
Flake Graphite

Cast iron is an iron alloy mainly composed of carbon and silicon, the amount of carbon is more than 2.1 mass%. Cast irons, gray cast iron and ductile cast iron, have been used as industrial parts and automobile parts widely because they have a good wear resistance and an excellent machinability. Graphite formation mechanism have been proposed, but, it is not established clearly yet. In this study, the microstructure of flake graphite was investigated to reveal the graphite formation mechanisms using FC250 alloy. Transmission electron microscopy (TEM) samples were prepared using focused ion beam (FIB). In the case of a cross section of flake graphite taken perpendicular to its elongated direction using TEM, internal microstructure of flake graphite was observed layered structure. In the case of a cross section of flake graphite taken parallel to its elongated direction, clear microstructure was not observed. Selected area electron diffraction (SAED) from flake graphite showed <0001> direction of graphite are mostly parallel to their thickness.

Property and Application of Austempered Ductile Cast Iron

2011 ◽  
Vol 328-330 ◽  
pp. 1297-1300
Author(s):  
Guang Si Luo
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Cast Iron ◽  
Treatment Process ◽  
Nodular Cast Iron ◽  
Ductile Cast Iron ◽  
Heat Treatment Process ◽  
Engineering Material ◽  
High Fatigue ◽  
Austempered Ductile Cast Iron

Austempered ductile cast iron is newly developed engineering material with a favorable combination of comprehensive mechanical properties. Its properties, such as good comprehensive mechanical properties, high fatigue strength, and good fiction and wear characteristics are included. The application of ADI at home and abroad was presented as well. In order to ensure and improve mechanical properties of ADI, it should ensure high rank nodularity in terms of nodular cast iron, improve graphite nodules, reduce segregation and properly cut down the content of silicon and manganese. While in terms of heat treatment, in order to achieve ideal austenite ferrites, stable and reliable heat treatment process as well as relevant equipment is required.

Study on the Plasma Beam Surface Remelting Modification of Nodular Cast Iron

2010 ◽  
Vol 152-153 ◽  
pp. 1751-1754 ◽  
Author(s):  
Li Yang ◽  
Gang Li
Keyword(s):  
Wear Resistance ◽  
Cast Iron ◽  
Nodular Cast Iron ◽  
Hardened Layer ◽  
Ductile Cast Iron ◽  
Graphite Phase ◽  
Plasma Beam ◽  
Hardness Tester ◽  
Operating Current ◽  
And Performance

To improve the wear resistance of ductile cast iron, plasma beam remelt-solidified hardening on the surface is adopted. Scanning electron microscope and micro-hardness tester is used to analyze the microstructure and performance for plasma beam remelt-solidified layer of nodular cast iron. The results show that micromelted-solidified hardening of the nodular cast iron surface can be obtained when the operating current is up to 50A. Along with the operating current increases, the width and depth of remelt-solidified layer and hardened layer increase, but the hardness goes down. After the hardening, graphite phase in remelt-solidified region is vanishing. The microstructure of remelt-solidified region is tiny ledeburite and remained austenite and of transformation hardening region is acicular martensite, remained austenite，spheroid graphite and ferrite .In transition region, martensite shell around nodular graphite appears, which is advantageous to enhance the wear resistance. From the surface to inner, the microhardness declines first and then increases, after achieving the maximum value the hardness slowly drops. The highest microhardness appears at the second-surface layer which has a certain distance to the surface.

Computational Modeling of the Microplasticization State in the Nodular Cast Iron

2014 ◽  
Vol 474 ◽  
pp. 285-290 ◽  
Author(s):  
Peter Kopas ◽  
Milan Vaško ◽  
Marián Handrik
Keyword(s):  
Plastic Deformation ◽  
Cast Iron ◽  
Graphite Particle ◽  
Basic Characteristic ◽  
Process Analysis ◽  
Nodular Cast Iron ◽  
Ductile Cast Iron ◽  
Particle Model ◽  
Plastic Zones ◽  
The Relationship

The article deals with the creation of models for the analysis of plastic zones generation in ductile cast iron. The aim is the study of the microplasticization process near the graphite particles border. In creating the graphite particle model there is randomly chosen shape and orientation of the particle. The basic characteristic of the shape is ovality (the ratio of the inscribed circle to the circumscribed circle). The size of plastic deformation and the size of the plastic area are monitored by the microplasticization process analysis. The results are statistically elaborated to determine the relationship between graphite particle ovality and microplasticization caused by an inclusion.

Gray Cast Iron Behavior in Cavitation Erosion

2014 ◽  
Vol 782 ◽  
pp. 269-274 ◽  
Author(s):  
Cinca Ionel Lupinca ◽  
Marian Dumitru Nedeloni ◽  
Dorian Nedelcu
Keyword(s):  
Cast Iron ◽  
Cavitation Erosion ◽  
Gray Cast Iron ◽  
Erosion Resistance ◽  
Nodular Cast Iron ◽  
Gray Cast ◽  
Spheroidal Graphite ◽  
Flake Graphite ◽  
Cast Irons ◽  
Cavitation Erosion Resistance

The paper presents the cavitation stand used, the work methodology, the trials realized on specimens of gray cast irons, with flake graphite and spheroidal-graphite, which were tested for cavitation erosion during different periods of time of the cavitation attack. Finally, the conclusions were interpreted on the basis of comparative graphics realized at the macro and microstructures level obtained for these two types of cast iron. Of the two types of gray cast iron, the nodular cast iron presents a better cavitation erosion resistance.

scholarly journals Abrasive effects of sediments on impellers of pumps used for catching raw water

2018 ◽  
Vol 22 (9) ◽  
pp. 591-596
Author(s):  
Rodrigo O. P. Serrano ◽  
Ana L. P. de Castro ◽  
Edwin A. M. Rico ◽  
Maria A. Pinto ◽  
Edna M. de F. Viana ◽  
...  
Keyword(s):  
Cast Iron ◽  
Abrasive Wear ◽  
Relative Velocity ◽  
Gray Cast Iron ◽  
Nodular Cast Iron ◽  
Sediment Concentration ◽  
Raw Water ◽  
Wear Coefficient ◽  
Micro Grooving ◽  
Sae 8620 Steel

ABSTRACT This study presents an analysis of the abrasive effects of sediments from the bed of the Acre River, Brazil, on the wear of three different ferrous materials employed in the manufacture of impellers of centrifuge pumps used to catch raw water. In order to evaluate the abrasive wear and specific wear coefficient (k) as a function of sediment concentration, tests were conducted in samples of SAE 8620 steel, nodular cast iron and gray cast iron by using a rotary-ball abrasion meter. These tests employed abrasive slurry with concentration of 1, 2, 3, 5 and 10 g L-1 of sediments in distilled water. The volume of worn material as a function of the relative velocity of water flow in relation to the impeller blades was mathematically estimated. The experimental results showed that: i) The semi-angular and semi-rounded shapes of the sediments from the Acre River produced evidence of micro-grooving and plastic deformation in the three metallic alloys; ii) SAE 8620 steel showed higher resistance to abrasive wear than samples of gray and nodular cast iron; iii) the increase in the volume of worn material due to increment in sediment concentration and the relative velocity of the mixture (water + sediment) to the rotor pads.

scholarly journals Sclero-topometry Metrology in Valorisation of Waste Oil for Micro-machining of Ductile Cast Iron

2013 ◽  
Vol 13 (4) ◽  
pp. 29-38 ◽  
Author(s):  
S. Eymard ◽  
Z. Ignaszak ◽  
T.G. Mathia
Keyword(s):  
Cast Iron ◽  
Nodular Cast Iron ◽  
Ductile Cast Iron ◽  
Transformer Oil ◽  
Critical Conditions ◽  
Optical Profilometry ◽  
Waste Oil ◽  
Base Oil ◽  
Unique Approach ◽  
Mechanisms Of Deformation

Abstract During the time, the specific characteristics and the efficient lifetime of oil progressively decrease, due to complex pollution, ultimately making the oil unsuitable for the initial applications. The strategy to regenerate and to valorise waste oils is investigated using improved combinations of sclerometric and topometric tests on ductile nodular cast iron. Tribo-abrasive tests are performed in critical conditions, with base oil, waste oil and regenerated oil, of similar viscosities in order to discriminate their interfacial performances. The forms of the scratch traces indicate wear resistance and tendency to elasto-plastic deformation. The mechanisms of deformation and frictional behaviours were evaluated using optical and Scanning Electron Microscopy and measured for various tribological conditions with tactile and optical profilometry. The Energy Dispersive X ray Spectroscopy completes the chemical superficial distribution of pertinent elements. The surface topography metrology is used to characterize the scratch profiles and to determine the volume of the displaced and removed material, as well as maximum pit height. The originality of this paper is that it is a unique approach specifically devoted to transformer oil concerning tribological conditions.

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