Thermal Analysis of Solidification Process and Mechanical Properties in Heavy Section Ductile Iron Casting

2013 ◽  
Vol 750-752 ◽  
pp. 454-461
Author(s):  
Wei Ping Chen ◽  
Li Wei Zhou ◽  
Wen Hui Li ◽  
Zhe Liu
Keyword(s):  
Mechanical Properties ◽  
Eutectic Reaction ◽  
Solidification Process ◽  
The Other ◽  
Eutectic Cell ◽  
Cooling Curves ◽  
Heavy Section ◽  
Chunky Graphite ◽  
Initial Graphite ◽  
Ductile Iron Casting

A heavy section ductile casting (HSDIC) with dimensions of Φ590 mm×800 mm was prepared. Cooling curves at the center, at 85 mm from the center, at 170 mm from the center and at 255 mm from the center of the casting were recorded and analyzed. The results show that the precipitation of initial graphite, nucleation of eutectic cell and mass eutectic reaction at 255 mm from the center were all earlier than the other three locations. Moreover, it takes the longest time of 53 minutes of recalescence at 170 mm from the center with the highest temperature rise of 7 °C, though the cooling rate at this location is not the lowest in the casting, the mechanical properties are the worst. In addition, the largest amount of chunky graphite appears at 170 mm from the center.

Effect of Carbon Equivalent on Graphite Formation in Heavy-Section Ductile Iron Parts

2010 ◽  
Vol 636-637 ◽  
pp. 523-530 ◽  
Author(s):  
Jacques Lacaze ◽  
S. Armendariz ◽  
Peio Larrañaga ◽  
Iker Asenjo ◽  
Jon Sertucha ◽  
...  
Keyword(s):  
Ductile Iron ◽  
Solidification Process ◽  
Carbon Equivalent ◽  
Post Inoculation ◽  
Cooling Curves ◽  
Eutectic Alloys ◽  
Clear Effect ◽  
Heavy Section ◽  
Chunky Graphite ◽  
Graphite Degeneracy

The influence of post-inoculation and of cerium and antimony additions on the solidification process and on the formation of chunky graphite in ductile iron heavy-section parts have been studied previously in the case of near-eutectic alloys. It appeared of interest to complement these works by analysing the effect of carbon equivalent on graphite degeneracy. In the present work, hypo-, hyper- and near-eutectic melts have been cast in large blocks and standard cups. Analysis of the corresponding cooling curves recorded during solidification as well as microstructure observations on these casts have been carried out. A clear effect of carbon equivalent as promoter of chunky graphite formation is observed. The results have been added to the set of data already available and various correlations are discussed.

scholarly journals Microstructure and Mechanical Properties of Novel Quasibinary Al-Cu-Yb and Al-Cu-Gd Alloys

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 476
Author(s):  
Sayed Amer ◽  
Ruslan Barkov ◽  
Andrey Pozdniakov
Keyword(s):  
Mechanical Properties ◽  
Tensile Properties ◽  
Mechanism Of Action ◽  
Annealing Temperature ◽  
Eutectic Reaction ◽  
Solidification Process ◽  
Annealed State ◽  
Microstructure And Mechanical Properties ◽  
Cold Rolled ◽  
Hot Rolled

Microstructure of Al-Cu-Yb and Al-Cu-Gd alloys at casting, hot-rolled -cold-rolled and annealed state were observed; the effect of annealing on the microstructure was studied, as were the mechanical properties and forming properties of the alloys, and the mechanism of action was explored. Analysis of the solidification process showed that the primary Al solidification is followed by the eutectic reaction. The second Al8Cu4Yb and Al8Cu4Gd phases play an important role as recrystallization inhibitor. The Al3Yb or (Al, Cu)17Yb2 phase inclusions are present in the Al-Cu-Yb alloy at the boundary between the eutectic and aluminum dendrites. The recrystallization starting temperature of the alloys is in the range of 250–350 °C after rolling with previous quenching at 590 and 605 °C for Al-Cu-Yb and Al-Cu-Gd, respectively. The hardness and tensile properties of Al-Cu-Yb and Al-Cu-Gd as-rolled alloys are reduced by increasing the annealing temperature and time. The as-rolled alloys have high mechanical properties: YS = 303 MPa, UTS = 327 MPa and El. = 3.2% for Al-Cu-Yb alloy, while YS = 290 MPa, UTS = 315 MPa and El. = 2.1% for Al-Cu-Gd alloy.

Effect of Yttrium and Magnesium Segregation on Microstructure and Mechanical Properties of Heavy Section Ductile Iron Castings

2011 ◽  
Vol 295-297 ◽  
pp. 1010-1016 ◽  
Author(s):  
Wei Ping Chen ◽  
Zhe Liu ◽  
Yu Deng ◽  
Jie Luo ◽  
Yong Cheng Chen
Keyword(s):  
Mechanical Properties ◽  
Ductile Iron ◽  
Magnesium Content ◽  
Solidification Mode ◽  
Iron Casting ◽  
Iron Castings ◽  
Microstructure And Mechanical Properties ◽  
Chunky Graphite ◽  
Main Factor ◽  
Ductile Iron Casting

Ductile iron specimen with dimensions of Φ590mm×800mm were prepared by treating the melt with an yttrium-containing nodulizer. Cooling curves at four locations____the center location, the location 85mm distant from the center, the location 170mm distant from the center and the location 255mm distant from the center of the heavy ductile iron casting Φ590mm×800mm was obtained. The effect of yttrium and magnesium on microstructure and mechanical properties was investigated, and the factors on the distribution of chunky graphite in the specimen were discussed as well. The results show that the largest amount of chunky graphite and the lowest mechanical properties appear at the location 170mm distant from the center. Excessive yttrium and magnesium content at the location 170mm distant from the center is the main factor for the large amount of chunky graphite. The characteristics of the solidification mode____pasty solidification and the considerably long solidification of the casting are the basic reasons for the distribution of chunky graphite of the heavy ductile iron casting Φ590mm×800mm.

scholarly journals Effect of Si and Ni Addition on Graphite Morphology in Heavy-Section Spheroidal Graphite Iron Parts

2018 ◽  
Vol 925 ◽  
pp. 70-77 ◽  
Author(s):  
Branko Bauer ◽  
Ivana Mihalic Pokopec ◽  
Mitja Petrič ◽  
Primož Mrvar
Keyword(s):  
Mechanical Properties ◽  
Cooling Rate ◽  
Metallographic Analysis ◽  
Spheroidal Graphite ◽  
Ni Content ◽  
Heavy Section ◽  
Graphite Morphology ◽  
Ni Addition ◽  
Chunky Graphite ◽  
Si Content

Metallographic analysis is applied to the study of the chunky graphite morphology in heavy-section castings of spheroidal graphite cast irons. Three castings with different Si and Ni content were prepared. Three positions in casting from the edge to the centre, with different cooling rates, were chosen for microstructure observation. The effect of the Si and Ni content on the graphite morphology and mechanical properties of heavy-section spheroidal graphite cast iron parts were investigated. Cerium containing commercial inoculant was used for in-stream inoculation. Chunky graphite area was estimated in micro-and macrostructure. Mechanical properties were determined on tensile test bars taken from the centre of the casting. Macro-and microstructure examination showed that the castings with high Si-content and Ni addition had chunky graphite present, while the castings produced by use of low Si and Ni containing charge had no chunky graphite. High Si-content is strong chunky graphite promoter, especially in castings with slow cooling rate. Ni addition also promotes chunky graphite formation, but only in thermal centre of the casting (where the cooling rate is the lowest). The elongation is severely lowered when chunky graphite appears in the microstructure.

Effect of Additives on Eutectoid Reaction and Mechanical Properties of Nb-Nb5Si3 Alloys

1998 ◽  
Vol 552 ◽  
Author(s):  
Seiji Miura ◽  
Yasuhiko Saeki ◽  
Tetsuo Mohri
Keyword(s):  
Mechanical Properties ◽  
Phase Transformation ◽  
Lamellar Structure ◽  
Solid Phase ◽  
Eutectic Reaction ◽  
Solidification Process ◽  
Eutectoid Reaction ◽  
Effect Of Additives ◽  
Solid Phase Transformation ◽  
Microstructural Control

For the improvement of mechanical properties, especially ductility, of intermetallic compoundbased alloys, microstructural control has been adopted to binary and higher-order systems. Although lamellar structure formed by a eutectic reaction has been attracting broad attention to ductilize alloys with a combination of brittle/ductile or brittle/brittle phases, it should be pointed out that the microstructure such as lamellar size or colony size is hard to be controlled after the solidification process. In that viewpoint, high-temperature solid-solid phase transformation provide significant advantages in handling and large super-cooling for the control of lamellar structure through eutectoid reaction.

scholarly journals The Effect of Laser Offset Welding on Microstructure and Mechanical Properties of 301L to TA2 with and without Cu Intermediate Layer

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1138 ◽  
Author(s):  
Xiaohui Zhao ◽  
Zhenfu Shi ◽  
Chao Deng ◽  
Yu Liu ◽  
Xin Li
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Brittle Fracture ◽  
Welded Joints ◽  
Intermediate Layer ◽  
Welded Joint ◽  
Eutectic Reaction ◽  
Dissimilar Materials ◽  
Microstructural Characterization ◽  
The Other

Based on dissimilar materials of 301L/TA2, the effect of laser offset and copper intermediate layer on welded joints was investigated. First, the process optimization of laser offsets indicated that the tensile strength of welded joint without intermediate layer was reached to the highest value when the laser was applied on the TA2 side. On the other hand, the tensile strength of welded joint with intermediate layer performed well when laser was applied in the middle position. Then, microstructural characterization and mechanical properties of welded joints were observed and tested. Based on eutectic reaction and peritectic reaction: TiFe and TiFe2 compounds were produced for welded joint without intermediate layer. Cu-Fe solid solutions and Cu-Ti compounds were generated when copper was used as the intermediate layer. The maximum tensile strength of welded joint with and without copper intermediate layer were 396 and 193 MPa, respectively. Finally, fracture mechanism of 301L/TA2 welded joint was studied: Fe-Ti compounds caused brittle fracture of welded joints without intermediate layer; brittle fracture took place in rich copper and Cu-Ti compounds area of welded joints with copper intermediate layer.

Microstructure Evolution of Heavy Section Ductile Iron

2010 ◽  
Vol 97-101 ◽  
pp. 1020-1023 ◽  
Author(s):  
Xiao Gang Diao ◽  
Zhi Liang Ning ◽  
Fu Yang Cao ◽  
Shan Zhi Ren ◽  
Jian Fei Sun
Keyword(s):  
Cooling Rate ◽  
Ductile Iron ◽  
Solidification Time ◽  
Cooling Curve ◽  
Eutectic Solidification ◽  
Spheroidal Graphite ◽  
Eutectic Cell ◽  
Cooling Curves ◽  
Iron Castings ◽  
Heavy Section

Ductile iron, Heavy section, Cooling curve, Microstructure, Cooling rate. Abstract. Two 250×250×250 mm cubic ductile iron castings solidified in sand and insulation mould were fabricated. The effect of cooling rate on graphite and matrix microstructure of heavy section ductile iron together with their cooling curves were evaluated. Results show that increasing the cooling rate leads to fine graphitization and favors spheroidal graphite formation. The matrix structure is fully ferrite structure at the edge of both castings, while pearlite can be seen near the eutectic cell boundaries at the center of two castings. Furthermore, the amount of pearlite increases with increasing solidification time. Cooling curves confirm that cooling rate affects solidification time of the eutectic transformation and characteristic temperature points on the cooling curves remain unchanged. Low cooling rate appears to significantly increase the eutectic plateau length. Besides, cooling curves show that eutectic temperature remains constant (about 1160°C), which allows for spheroidal graphite formation. Undercooling and inoculation fading during the long time eutectic solidification lead to pearlite formation in the center of cubic ductile iron castings.

scholarly journals Chunky Graphite in Low and High Silicon Spheroidal Graphite Cast Irons–Occurrence, Control and Effect on Mechanical Properties

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5402
Author(s):  
Jon Sertucha ◽  
Garikoitz Artola ◽  
Urko de La Torre ◽  
Jacques Lacaze
Keyword(s):  
Mechanical Properties ◽  
Rare Earth ◽  
Rare Earths ◽  
Room Temperature ◽  
Spheroidal Graphite ◽  
Cast Irons ◽  
Charge Materials ◽  
Heavy Section ◽  
Chunky Graphite ◽  
High Silicon

Chunky graphite appears easily in heavy-section spheroidal graphite cast irons and is known to affect their mechanical properties. A dedicated experiment has been developed to study the effect of the most important chemical variables reported to change the amount of chunky graphite, namely the content in silicon and in rare earths. Quite unexpectedly, controlled rare earths contents appear beneficial for decreasing chunky graphite when using standard charge materials. Tin is shown to decrease chunky graphite appearance and it is evidenced that this effect is not related to rare earths. Finally, the effect of tin and antimony are compared and it is noticed that both suppress chunky graphite but also lead to some spiky graphite when no rare earth is added. Chunky graphite negatively affects the room temperature mechanical properties, though much more in the case of low silicon spheroidal graphite cast irons than in high silicon ones. Spiky graphite has been found to be much more detrimental and should thus be avoided.

scholarly journals Microstructure and Mechanical Properties of Ultrafine Quaternary Al-Cu-Si-Mg Eutectic Alloy

Metals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 7
Author(s):  
Qing Cai ◽  
Brian Cantor ◽  
Vivian S. Tong ◽  
Feng Wang ◽  
Chamini L. Mendis ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Eutectic Alloy ◽  
Cast Alloy ◽  
Eutectic Reaction ◽  
High Strength ◽  
Eutectic Structure ◽  
Eutectic Cell ◽  
Orientation Relationships ◽  
Arc Melting ◽  
Alloy Microstructure

The microstructure evolution and mechanical properties of quaternary Al-Cu-Si-Mg eutectic alloy prepared via arc melting and suction casting were studied. This alloy exhibits a single endothermic DSC peak with a melting temperature of 509 °C upon heating, suggesting a eutectic reaction. The cast alloy microstructure consisted of four phases, α-Al, Al2Cu (), Si and Al4Cu2Mg8Si7 (Q), in the eutectic cells and also in the nano-scale anomalous eutectic in the intercellular regions. The eutectic cells show different morphologies in different parts of the sample. Well-defined orientation relationships between the α-Al, Al2Cu, and Q phases were found in the eutectic cell centres, while decoupled growth of Q phase occurred at the cell boundaries. The bimodal microstructure exhibits excellent compressive mechanical properties, including a yield strength of 835 ± 35 MPa, a fracture strength of ~1 GPa and a compressive fracture strain of 4.7 ± 1.1%. The high strength is attributed to a combination of a refined eutectic structure and strengthening from multiple hard phases.

About Ultrasonic Melt Treatment during Solidification and its Influence on Grain Size and Mechanical Properties of Magnesium Alloy AZ 91

2010 ◽  
Vol 649 ◽  
pp. 295-300 ◽  
Author(s):  
Katja Pranke ◽  
Klaus Eigenfeld
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Magnesium Alloy ◽  
Maximum Amplitude ◽  
Solidification Process ◽  
Cooling Curves ◽  
Constant Frequency ◽  
Melt Treatment ◽  
Ultrasound Generator ◽  
Ultrasonic Melt Treatment

We investigated the influence of varying amplitudes at constant frequency on the grain size and mechanical properties of magnesium alloy AZ 91. Our experimental setup consists of an ultrasound generator connected to a steel gravity die by screw fitting. Magnesium alloy AZ 91 has been melted in a closed-argon-flooded steel crucible and poured into the die while ultrasound was generated. Cooling curves were recorded during the whole solidification process. The grain size and the mechanical properties were determined and analyzed. As a result, we achieved reduction in grain size as well as an increase in tensile strengths for amplitudes of up to 40% of the maximum amplitude. Yield strengths could be minimally improved in all experiments. The values of elongation and hardness (Brinell) could also be improved for nearly all investigated amplitudes. In summary it is possible to achieve both: grain refinement and increase in tensile strength, hardness and elongation.

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