scholarly journals Pitting strength estimate for cast iron and copper alloy materials

2021 ◽  
Vol 49 (2) ◽  
pp. 269-279
Author(s):  
Edward Osakue ◽  
Lucky Anetor ◽  
Kendall Harris
Keyword(s):  
Cast Iron ◽  
Copper Alloy ◽  
Fatigue Testing ◽  
Copper Alloys ◽  
Contact Fatigue ◽  
Ductile Cast Iron ◽  
Cast Irons ◽  
Design Factor ◽  
Initial Design ◽  
Proof Strength

An attempt is made to predict the pitting strength of cast iron and copper alloy materials from their compressive yield or compressive proof strength for a reliability of 99% at 107 load cycles. The compressive yield or compressive proof strength is related to the tensile strength of ductile cast iron and copper alloy materials by a proportionality factor. Two proportionality factors are used for brittle cast iron materials. The pitting strength formulation incorporates a nominal design factor at 99% reliability which is estimated from a probabilistic model based on the lognormal probability density function. Pitting strength estimates from the predictions are compared with those of American Gear Manufacturers Association (AGMA) estimates and data from other sources. The predicted values for gray cast irons had variances in the range of -11.28% to 25%. Ductile cast iron pitting strength estimates deviated from those of AGMA by -30.28% to 1.73% and 16.76% to 36.34% for Austempered ductile irons. The variances obtained for cast bronze were from 11.17% and 14.73%, but the sample size was small. These variances appear to be reasonable due to the many factors that can influence pitting resistance. Since pitting strength data for many grades of cast iron and copper alloys are not available (especially in the public domain), they may be estimated by the expressions developed in this study for initial design sizing. Also, the pitting strength of new cast iron and copper alloy materials could likewise be estimated for initial design sizing. This will eliminate long and costly contact fatigue testing at the initial design phases, which of course is necessary for design validation.

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 INVESTIGATION ON TRIBOLOGICAL BEHAVIOR OF DUCTILE CAST IRONS WITH NANOSIZED PARTICLES

2019 ◽  
Vol 3 ◽  
pp. 84
Author(s):  
Julieta Kaleicheva ◽  
Valentin Mishev ◽  
Manahil Tongov
Keyword(s):  
Wear Resistance ◽  
Cast Iron ◽  
Titanium Nitride ◽  
Tribological Behavior ◽  
Ductile Cast Iron ◽  
Titanium Carbonitride ◽  
Nanosized Particles ◽  
Cast Irons ◽  
Nickel Deposition ◽  
Graphite Phase

The work in this study is focused on investigation of the tribological behavior of ductile cast iron with nanosized particles: titanium nitride TiN; titanium nitride 30% + titanium carbonitride 70% (30%TiN+70%TiCN). The ductile cast iron composition is: Fe-3,55C-2,67Si-0,31Mn-0,009S-0,027P-0,040Cu-0,025Cr-0,08Ni-0,06Mg wt%. Before the addition to the melt nanosized particles were coated with nickel by the electroless nickel deposition method EFFTOMNICKEL .The nickel coating on the nanosized particles ensures their wetting in the melt as well as their uniform distribution into the cast. The optical and quantity metallographic observations and wear test are performed to study the influence of the nanoparticle additives on the cast iron tribological properties. It is observed that the quantity proportion changes between pearlite, ferrite and graphite phase in the cast iron structure. The graphite shape is retained the same, but the nanosized additives decrease the average diameter of the graphite spheres Dmid and increase the quantity of the graphite phase in the structure of ductile cast irons. The cast iron wear resistance in the presence of nanosized additives of (TiN+TiCN) and TiN increases to 55–69% in comparison to wear resistance of the cast iron without nanoparticles.

scholarly journals Influence of nickel addition and casting modulus on the properties of hypo-eutectic ductile cast iron

2019 ◽  
Vol 55 (2) ◽  
pp. 283-293 ◽  
Author(s):  
E. Colin-García ◽  
A. Cruz-Ramírez ◽  
G. Reyes-Castellanos ◽  
J.A. Romero-Serrano ◽  
R.G. Sánchez-Alvarado ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Cast Iron ◽  
Cooling Rate ◽  
Ductile Iron ◽  
Ductile Cast Iron ◽  
Strength Ratio ◽  
Cast Irons ◽  
Microstructural Changes ◽  
Nodule Count ◽  
Nickel Addition

The effect of the casting modulus on the distribution and features of graphite in hypo-eutectic ductile iron unalloyed and alloyed with nickel (0.88 wt %) was studied. The cooling rate of the casting plates of 25.4, 12.7 and 8.5 mm in thickness with a casting modulus of 6.87, 4.46 and 3.31 mm, respectively promotes several microstructural changes, such as cementite precipitation and a noticeable nodule count increment. The nickel addition suppressed the cementite formation and improved the nodule count and nodularity for the three casting modulus evaluated. The nickel addition increased the nodule count in 69, 67 and 128 % for the modulus of 3.31, 4.46 and 6.87 mm, respectively, regarding the unalloyed ductile iron. It was found that the biggest casting modulus produced the biggest nodules with the lowest nodule count for both ductile cast irons. Further to the improvements in the graphite features, the nickel addition allowed to keep almost constant the yield and tensile strength ratio for the different casting modulus.

Mechanical Properties and Thermal Expansion Characteristics of Low Thermal Expansion Ductile Cast Iron with same Nickel Equivalent (NiE)

2010 ◽  
Vol 457 ◽  
pp. 380-385
Author(s):  
Minoru Hatate ◽  
Tohru Nobuki ◽  
Shoji Kiguchi ◽  
Kazumichi Shimizu
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Thermal Expansion ◽  
Cast Iron ◽  
Coefficient Of Thermal Expansion ◽  
Solution Treatment ◽  
Ductile Cast Iron ◽  
High Dimensional ◽  
Cast Irons ◽  
Low Thermal Expansion

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.

scholarly journals Structure Distribution in Precise Cast Iron Moulded on Meltable Model

2015 ◽  
Vol 15 (4) ◽  
pp. 69-74 ◽  
Author(s):  
B. Skrbek ◽  
K. Policar
Keyword(s):  
Quality Improvement ◽  
Cast Iron ◽  
Ductile Cast Iron ◽  
Spheroidal Graphite ◽  
Flake Graphite ◽  
Cast Irons ◽  
Remanent Magnetism ◽  
Measurement Results ◽  
Mechanical And Physical Properties ◽  
Grey Cast

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.

Modeling of Distribution of Visible and Non-Visible Graphite Nodules Embedded in the Surface Layer of Ductile Cast Iron

2010 ◽  
Vol 659 ◽  
pp. 453-458
Author(s):  
Tamás Réti ◽  
Mihály Réger ◽  
Ágnes Csizmazia ◽  
Imre Czinege
Keyword(s):  
Cast Iron ◽  
Surface Defects ◽  
Defect Formation ◽  
Structural Parameters ◽  
Ductile Cast Iron ◽  
Graphite Nodule ◽  
Image Analyzer ◽  
Local Surface ◽  
Cast Irons ◽  
Surface Damages

The graphite nodule count and size distribution are important structural parameters in the quantitative characterization of the microstructure of ductile cast irons. In several cases, it is observed that local surface damages (cracks or microchip formations) are generated by the final manufacturing process (superfinishing operation), and these defects are originated basically from the hidden (invisible) graphite nodules located directly below surface. Based on measured data obtained by an image analyzer, a stereological model and a simulation algorithm have been developed to analyse the correspondances between the graphite morphology and the defect formation. This method makes it possible to establish a correlation between the microstructure parameters and the occurrence of local surface defects on ductile cast iron components.

scholarly journals Methodology for Determination of Degree of Nodularity in a Ductile Cast Iron GGG 40 by Ultrasonic Velocity Test

2018 ◽  
Vol 26 (26) ◽  
pp. 10-16
Author(s):  
Douglas Agnoletto ◽  
Guilherme Vieira Braga Lemos ◽  
Arthur Bortolini Beskow ◽  
Cleber Rodrigo de Lima Lessa ◽  
Afonso Reguly
Keyword(s):  
Cast Iron ◽  
Ultrasonic Method ◽  
Iron Alloy ◽  
Ductile Cast Iron ◽  
Cast Irons ◽  
Ultrasonic Sound ◽  
Time Savings ◽  
Carbon Iron ◽  
Microstructural Examination

Cast iron alloys combine many elements such as carbon, iron, silicon, magnesium and can be usually classified according to their microstructure in ductile, gray, compacted, white, and malleable. Each one has particularities in terms of properties and applications. Hence, this study aims to evaluate the degree of nodularity (%) in a ductile cast iron alloy GGG 40. In this context, a methodology to investigate the degree of nodularity was proposed. The ultrasonic method was used to determine the amount of ductile graphite as well as for parts release and thus facilitated the industrial operational execution. The effect of ultrasonic sound was investigated in sixtyseven ductile cast irons, and these analyses were further compared to the level of nodularity observed by metallography. Finally, based on the findings, the cast iron quality was guaranteed, leading to time-savings, avoiding the microstructural examination, and thus promoting cost reductions.

Ultrasonic Inspection for Microstructural and Mechanical Properties of Ductile Cast Iron

2021 ◽  
Vol 39 ◽  
pp. 9-19
Author(s):  
Özer Özdemir ◽  
Selim Gürgen ◽  
Melih Cemal Kuşhan
Keyword(s):  
Mechanical Properties ◽  
Cast Iron ◽  
Sound Speed ◽  
Ultrasonic Inspection ◽  
Flaw Detection ◽  
Wide Frequency Range ◽  
Ductile Cast Iron ◽  
Cast Irons ◽  
Ultrasonic Sound ◽  
Graphite Morphology

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.

Spheroidal Graphite Cast Irons (or Ductile Cast Iron)

2018 ◽  
pp. 105-140
Author(s):  
José Antonio Pero-Sanz Elorz ◽  
Daniel Fernández González ◽  
Luis Felipe Verdeja
Keyword(s):  
Cast Iron ◽  
Ductile Cast Iron ◽  
Spheroidal Graphite ◽  
Cast Irons
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