scholarly journals Microstructural and Mechanical Assessment of Camshafts Produced by Ductile Cast Iron Low Alloyed with Vanadium

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 146
Author(s):  
Eduardo Colin García ◽  
Alejandro Cruz Ramírez ◽  
Guillermo Reyes Castellanos ◽  
Jaime Téllez Ramírez ◽  
Antonio Magaña Hernández
Keyword(s):  
Ductile Iron ◽  
Volume Fraction ◽  
Mechanical Tests ◽  
Ductile Cast Iron ◽  
Homogeneous Distribution ◽  
Spheroidal Graphite ◽  
Middle Region ◽  
Nodule Count ◽  
Mold Casting ◽  
Cast Alloys

In the present study, ductile iron camshafts low alloyed with 0.2 and 0.3 wt % vanadium were produced to study the microstructural and mechanical evaluation of lobes and camshaft. For this purpose, camshafts were produced in one of the largest manufacturers of the ductile iron camshaft in México by the phenolic urethane no-bake sand mold casting method. The microstructure of the lobes was studied in three zones located at the top, middle, and bottom of the lobes by optical microscopy, and mechanical tests were performed on lobes and camshafts. A homogeneous distribution of spheroidal graphite with high nodularity for both castings was obtained from the regions of the lobes analyzed. The high cooling rate on the lobe surfaces enabled us to obtain a high nodule count of a smaller size instead of the middle region where big nodules with a low nodule count are presented. An inverse chill behavior was found in the middle region of the lobes where there is an increase in the concentration of carbide-forming elements, leading to the highest micro-hardness values in this region. The tensile properties were increased when the vanadium contents were increased; however, the toughness and ductility of the as-cast alloys were decreased as a result of the increase of the volume fraction of carbide particles.

scholarly journals Heat Treatment Evaluation for the Camshafts Production of ADI Low Alloyed with Vanadium

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1036
Author(s):  
Eduardo Colin García ◽  
Alejandro Cruz Ramírez ◽  
Guillermo Reyes Castellanos ◽  
José Federico Chávez Alcalá ◽  
Jaime Téllez Ramírez ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Ductile Iron ◽  
Volume Fraction ◽  
Energy Impact ◽  
Treatment Conditions ◽  
Mold Casting ◽  
Grade 3 ◽  
Good Agreement

Ductile iron camshafts low alloyed with 0.2 and 0.3 wt % vanadium were produced by one of the largest manufacturers of the ductile iron camshafts in México “ARBOMEX S.A de C.V” by a phenolic urethane no-bake sand mold casting method. During functioning, camshafts are subject to bending and torsional stresses, and the lobe surfaces are highly loaded. Thus, high toughness and wear resistance are essential for this component. In this work, two austempering ductile iron heat treatments were evaluated to increase the mechanical properties of tensile strength, hardness, and toughness of the ductile iron camshaft low alloyed with vanadium. The austempering process was held at 265 and 305 °C and austempering times of 30, 60, 90, and 120 min. The volume fraction of high-carbon austenite was determined for the heat treatment conditions by XRD measurements. The ausferritic matrix was determined in 90 min for both austempering temperatures, having a good agreement with the microstructural and hardness evolution as the austempering time increased. The mechanical properties of tensile strength, hardness, and toughness were evaluated from samples obtained from the camshaft and the standard Keel block. The highest mechanical properties were obtained for the austempering heat treatment of 265 °C for 90 min for the ADI containing 0.3 wt % V. The tensile and yield strength were 1200 and 1051 MPa, respectively, while the hardness and the energy impact values were of 47 HRC and 26 J; these values are in the range expected for an ADI grade 3.

scholarly journals Effect of Processing Parameters on the Mechanical Properties of Heavy Section Ductile Iron

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Mohamed Mahmoud Mourad ◽  
Shimaa El-Hadad ◽  
Mervat Mohamed Ibrahim ◽  
Adel Abdelmonem Nofal
Keyword(s):  
Mechanical Properties ◽  
Ductile Iron ◽  
Processing Parameters ◽  
Ductile Cast Iron ◽  
Heavy Section ◽  
The Matrix ◽  
Cast Alloys ◽  
One Step ◽  
Inoculation Procedure ◽  
Inoculation Treatment

The main objective of the current work is to investigate the influence of different inoculation conditions on the microstructure and mechanical properties of heavy section ductile iron (DI) castings. Inoculation treatment was done via one step and double step treatments with different amounts of inoculants. The mechanical properties of the fabricated samples were evaluated. The best inoculation procedure in terms of graphite nodules characteristics and mechanical properties was double inoculation with 0.8% inoculants added at first and 0.2% in the late inoculation step. The presence of Sb in one of the cast alloys controlled the growth of graphite nodules in these heavy section ductile iron castings; however low impact toughness was recorded. The matrix structure of ductile cast iron showed a significant influence not only on the strength and impact properties but also on the fracture mode during testing.

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.

scholarly journals Ultrafine Ductile and Austempered Ductile Irons by Solidification in Ultrasonic Field

2021 ◽  
Author(s):  
M. Ahmed ◽  
E. Riedel ◽  
M. Kovalko ◽  
A. Volochko ◽  
R. Bähr ◽  
...  
Keyword(s):  
Ductile Iron ◽  
Acoustic Waves ◽  
Iron Alloy ◽  
Austempered Ductile Iron ◽  
Maximum Speed ◽  
Spheroidal Graphite ◽  
Dual Phase ◽  
Nodule Count ◽  
The Matrix ◽  
Sg Iron

AbstractIn this research, ultrasonic melt treatment (UST) was used to produce a new ultrafine grade of spheroidal graphite cast iron (SG iron) and austempered ductile iron (ADI) alloys. Ultrasonic treatment was numerically simulated and evaluated based on acoustic wave streaming. The simulation results revealed that the streaming of the acoustic waves propagated as a stream jet in the molten SG iron along the centerline of the ultrasonic source (sonotrode) with a maximum speed of 0.7 m/s and gradually decreased to zero at the bottom of the mold. The metallographic analysis of the newly developed SG iron alloy showed an extremely ultrafine graphite structure. The graphite nodules’ diameter ranging between 6 and 9 µm with total nodule count ranging between 900 to more than 2000 nodules per mm2, this nodule count has never been mentioned in the literature for castings of the same diameter, i.e., 40 mm. In addition, fully ferritic matrix was observed in all UST SG irons. Further austempering heat treatments were performed to produce different austempered ductile iron (ADI) grades with different ausferrite morphologies. The dilatometry studies for the developed ADI alloys showed that the time required for the completion of the ausferrite formation in UST alloys was four times shorter than that required for statically solidified SG irons. SEM micrographs for the ADI alloys showed an extremely fine and short ausferrite structure together with small austenite blocks in the matrix. A dual-phase intercritically austempered ductile iron (IADI) alloy was also produced by applying partial austenitization heat treatment in the intercritical temperature range, where austenite + ferrite + graphite phases coexist. In dual-phase IADI alloy, it was established that introducing free ferrite in the matrix would provide additional refinement for the ausferrite.

EFFECT OF Ce ON GRAPHITE NODULE COUNT AND SIZE DISTRIBUTION IN DUCTILE IRON

2009 ◽  
Vol 23 (06n07) ◽  
pp. 1853-1860 ◽  
Author(s):  
XIAOGANG DIAO ◽  
ZHILIANG NING ◽  
FUYANG CAO ◽  
JIANFEI SUN
Keyword(s):  
Size Distribution ◽  
Ductile Iron ◽  
Graphite Nodule ◽  
Spheroidal Graphite ◽  
Nodule Count ◽  
Edx Analysis ◽  
Spherical Graphite ◽  
Mean Diameter ◽  
Addition Level

The graphite nodule density and size distribution are two very important parameters in the characterization of the microstructures of ductile iron. Various amount of cerium element ( Ce ) (from 0.005% to 0.020%) were added into ductile iron cast in sand moulds to investigate the effect of Ce concentration on graphite nodule count and size distribution. The addition of Ce has a significant effect on solidified microstructures of ductile iron. Increasing of Ce concentration from 0.005% to 0.014%, an obvious increase in nodule graphite amount is achieved and graphite size becomes finer. When the addition level of Ce reaches 0.018% or 0.020%, spheroidal graphite begins to coarsen, resulting in the decrease in graphite amount and formation of the some non-spherical graphite. An evident nucleus and faceted crystals inside a nodule are clearly distinguished and the thin flakes that constitute the nodule are observed from the SEM photograph. EDX-analysis of nucleus of the spheroidal graphite shows that it is composed of sulfur, cerium, magnesium and trace calcium. The 3-D nodule count of ductile iron is 11.7 × 103/ mm 3 with 0.005% Ce addition. The value is 45.8 × 103/ mm 3 with Ce addition up to 0.014% and the majority of diameter is less than 30 µm. However, with 0.018% Ce residual, the nodule count decreases to 29.0 × 103/ mm 3. The value is close to that of 0.018% Ce when Ce concentration is 0.020%, and the majority of diameter is less than 40 µm. The results indicate that the graphite nodule count reaches the maximum and mean diameter reaches the minimum with 0.014% Ce residual existing in ductile iron.

scholarly journals Study of the Influence of Alloying Elements on the Mechanical Characteristics and Wear Behavior of a Ductile Cast Iron

2021 ◽  
Vol 15 (56) ◽  
pp. 74-83
Author(s):  
Iliasse Boulifa ◽  
Ali Hadji
Keyword(s):  
Cast Iron ◽  
Ductile Iron ◽  
Mechanical Characteristics ◽  
Wear Behavior ◽  
Impact Resistance ◽  
Ductile Cast Iron ◽  
Alloying Elements ◽  
Spheroidal Graphite ◽  
Agricultural Tractors ◽  
Wear Tests

In the present work, the influence of alloying elements, on the mechanical characteristics and wear behavior by modification of the chemical composition of the ductile iron was studied, in order to improve these characteristics for the manufacture of agricultural tractors parts in particular front and rear axles, ploughshares, gear crankcase, pinions, transmission shafts, crankshafts, etc... The cast iron investigated was prepared in an induction furnace at 1500°C and inoculated with a ferro-silicon-magnesium to 45% Si and 10% Mg. The specimens were casted into self-hardening sand moulds at 1450°C, after an addition of alloying elements, Manganese (0.6%), Nickel (0.5%), Molybdenum (0.2%) and Vanadium(0.1%)) in the base spheroidal graphite cast iron produced. Various techniques, Optical microscopy, Microhardness, Hardness, Tensile strength, Impact resistance, and Wear tests (Wear resistance and Friction coefficient) were used to characterize these specimens. The obtained results show that the tested samples have ductile iron structures formed by ferrite and pearlite. Moreover, mechanical and wear tests prove that the alloyed cast iron has improved characteristics compared to unalloyed cast iron and shows the positive effect of alloying elements on these characteristics.

Nodule count in ductile iron: theoretical model based on Weibull statistics

2005 ◽  
Vol 18 (3) ◽  
pp. 156-162 ◽  
Author(s):  
E. Fraś ◽  
K. Wiencek ◽  
M. Górny ◽  
H. F. López
Keyword(s):  
Theoretical Model ◽  
Ductile Iron ◽  
Weibull Statistics ◽  
Nodule Count ◽  
Model Based

Permanent Mold Casting Practice and Microstructure and Mechanical Properties of Thin-Sectioned ADI Casting

2007 ◽  
Vol 26-28 ◽  
pp. 531-534
Author(s):  
B.M. Moon ◽  
Bong Hwan Kim ◽  
Je Sik Shin ◽  
Sang Mok Lee
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Ductile Cast Iron ◽  
Treatment Temperature ◽  
Chemical Compositions ◽  
Permanent Mold ◽  
Permanent Mold Casting ◽  
Treatment Practice ◽  
Mold Casting ◽  
Si Content

For thin-walled casting development of austempered ductile iron (ADI), permanent mold casting and accompanied heat treatment practice were systematically investigated to suppress and/or remove chill defects of ductile cast iron (DCI) with various thickness of 2 to 9 mm and to ensure mechanical properties of the final ADI casting. Si content was increased up to 3.8% to reduce the chill formation tendency under a high cooling rate. The residual Mg content remarkably affected the nodule count, while the nodule size and spherodization were proven to have weak relationships. Austenitizing process followed by austempering was very sensitive to chemical compositions (Si and Sn) and heat treatment temperature. As a practical application, the steel bar coupler for a structural frame was tried to produce without subsequent machining.

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