scholarly journals STRUCTURE AND MECHANICAL PROPERTIES OF SPHEROIDAL GRAPHITE CAST IRON WITH NANOSIZED ADDITIVES

Author(s):  
Julieta Kaleicheva ◽  
Valentin Mishev ◽  
Zdravka Karaguiozova ◽  
Galina Nikolcheva

The microstructure and properties of spheroidal graphite cast irons and austempered ductile irons with nanosized additives of titanium carbonitride and titanium nitride (TiCN+TiN), titanium nitride TiN and cubic boron nitride cBN are investigated. The microstructure of the patterns is observed by optical metallography, quantity metallographic analysis, X-Ray analysis, SEM analysis and EDX analysis. Hardness measurement, impact strength and abrasion wear test on fixed abrasive are performed. The influence of the nanosized additives on the microstructure, mechanical and tribological properties of the cast irons are examined.

Author(s):  
Julieta Kaleicheva ◽  
Valentin Mishev ◽  
Manahil Tongov

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.


2009 ◽  
Vol 2009 ◽  
pp. 1-5 ◽  
Author(s):  
Du Xiaodong ◽  
Sun Guodong ◽  
Wang Yifei ◽  
Wang Jianfeng ◽  
Yang Haoyu

The abrasion behavior of high manganese steel is investigated under three levels of impact energy in acid-ironstone slurry. The wear test was carried out by an MLDF-10 tester with impact energy of 0.7 J, 1.2 J, and 1.7 J. The impact abrasion property of high manganese steel in corrosive condition was compared according to the wear mass loss curves. The wear mechanism was analysed by the SEM analysis of the worn surface and the optical metallographic analysis of the vertical section to the wear surface. The results show that the impact energy has a great effect on the impact corrosion and abrasion properties of it. Its abrasion mechanism in corrosive condition is mainly microplough and breakage of plastic deformed ridges and wedges under the impact energy of 0.7 J. It is mainly the spelling of plastic deformed ridges and wedges under 1.2 J and the spalling of the work-hardening layer under 1.7 J after a long time testing.


2020 ◽  
Vol 994 ◽  
pp. 104-111
Author(s):  
Julieta Atanasova Kaleicheva ◽  
Valentin Plamenov Mishev ◽  
Zdravka Kirilova Karaguiozova

In the present study austempered ductile irons (ADI) with lower bainitic structure are investigated. Nanosized particles (50nm) of titanium carbonitride + titanium nitride TiCN+TiN and titanium nitride TiN are added to the casting volume. The samples microstructure is studied by optical metallography and X-Ray analysis. The influence of the nanosized additives on the kinetics of the bainitic transformation and on the morphology of the bainitic structure is investigated. The abrasive wear testing, hardness measurements and impact strength are carried out. It is established that the presence of nanoadditives in the bainitic cast irons leads to the changes in their microstructure which increases their mechanical characteristics and abrasive wear resistance. The studied nanocomposite materials expand the potential for new ADI applications in the industry.


Alloy Digest ◽  
2020 ◽  
Vol 69 (11) ◽  

Abstract Meehanite GB300 is a pearlitic gray cast iron that has a minimum tensile strength of 300 MPa (44 ksi), when determined on test pieces machined from separately cast, 30 mm (1.2 in.) diameter test bars. This grade exhibits high strength while still maintaining good thermal conductivity and good machinability. It is generally used for applications where the thermal conductivity requirements preclude the use of other higher-strength materials, such as spheroidal graphite cast irons, which have inferior thermal properties. This datasheet provides information on physical properties, hardness, tensile properties, and compressive strength as well as fatigue. It also includes information on low and high temperature performance as well as heat treating, machining, and joining. Filing Code: CI-75. Producer or source: Meehanite Metal Corporation.


1988 ◽  
Vol 3 (5) ◽  
pp. 1010-1020 ◽  
Author(s):  
Hua Tan ◽  
Thomas J. Ahrens

Cubic boron nitride (C–BN)' powders admixed with graphite-structured boron nitride powder (g-DN), silicon carbide whisker (SCW), or silicon nitride whisker (SNW) were shock compacted to pressures up to 22 GPa. Unlike previous work with diamond and graphite [D. K. Potter and T. J. Ahrens, J. Appl. Phys. 63, 910 (1987) it was found that the addition of g-BN inhibited dynamic consolidation. Good consolidation was achieved with a 4–8 μm particle size C–BN powder admixed with 15 wt.% SNW or 20 wt.% SCW whereas a 37–44 μm particle size C–BN mixture was only poorly consolidated. Scanning electron microscopy (SEM) analysis demonstrates that SCW and SNW in the mixtures were highly deformed and indicated melt textures. A skin heating model was used to describe the physics of consolidation. Model calculations are consistent with SEM analysis images that indicate plastic deformation of SCW and SNW. Micro-Vickers hardness values as high as 50 GPa were obtained for consolidated C–BN and SNW mixtures. This compares to 21 GPa for single-crystal Al2O3 and 120 GPa for diamond.


Alloy Digest ◽  
2021 ◽  
Vol 70 (9) ◽  

Abstract ISO 185/JL/350 is a higher-tensile-strength gray cast iron that has a pearlitic matrix, and a tensile strength of 350–450 MPa (51–65 ksi), when determined on test pieces machined from separately cast, 30 mm (1.2 in.) diameter test bars. It provides a combination of high strength while still maintaining good thermal conductivity compared with other types of cast iron. This grade approaches the maximum tensile strength attainable in gray cast iron. Applications therefore tend to be confined to those where thermal conductivity requirements in service preclude the use of one of the other higher-strength materials such as spheroidal graphite cast irons, which have inferior thermal properties. This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on wear resistance as well as casting and heat treating. Filing Code: CI-85. Producer or source: International Organization for Standardization.


2007 ◽  
Vol 561-565 ◽  
pp. 925-928 ◽  
Author(s):  
Seijiro Maki ◽  
Kazuhito Suzuki ◽  
Kenichiro Mori

Feasibility of semisolid forging of cast iron using rapid resistance heating was experimentally investigated. Gray pig iron FC250 and spheroidal graphite cast iron FCD600, whose carbon equivalents are both 4.3% in mass, were used for the experiments. Since these cast irons have a narrow semisolid temperature range, an AC power supply with an input electric energy control function was used. In this study, the resistance heating characteristics of the cast irons were firstly examined, and then their semisolid forging experiments were conducted. In the forging experiments, the conditions of the forgings such as microstructures and hardness properties were examined, and the feasibility of the semisolid forging of cast iron using resistance heating was discussed. As a result, it was found that the method presented here is highly feasible.


2017 ◽  
Vol 08 (13) ◽  
pp. 948-958 ◽  
Author(s):  
Tohru Nobuki ◽  
Minoru Hatate ◽  
Toshio Shiota

Author(s):  
A. I. Pokrovskii ◽  
B. B. Khina ◽  
O. A. Tolkacheva

The experience of the Physico-technical Institute (PhTI) of the National Acdemy of Sciences of Belarus in the harmonization of international standard ISO 17804 (Founding – Ausferritic spheroidal graphite cast irons – Classification) and development of the Belorussian analogue STB ISO is described. The reasons for the choice of austempered ductile iron (ADI) as an object for standard harmonization are presented: it is the most promising cast iron in comparison with gray and classical ductile iron. The work procedure on harmonization is described: how to include the task into the State Plan on standardization, specificity of translation of the text, peculiarities of with state organizations responsible for approbation of standards such as Belorussian Institute for Standardization and Certification (BelGISS) and State Committee on Standards (Gosstandart), writing a summary of external reviews, working with critical comments from potential users. It is outlined that any foreign standard does not exists independently but is closely connected with at least 10 to 20 other standards. Thus, harmonization necessitates coordination with other standards and sometimes even with handbooks by adding annexes to the main text. The importance of a proper choice of the standard status is outlined: identical (ID) or modified (MOD). Developing an identical standard is prestigious but difficult because is requires harmonization of all the referenced standards, which is a very labor-consuming procedure. It is argued that the most suitable is ‘intermediate’ variant: adopting the authentic text of the international standard (in high-quality translation) but with annexes reflecting national specificity in this area. As a result, a harmonized standard is developed which, for the first time in Belarus, standardize the tensile strength of 800 MPa in combination with the elongation of 10 % and the tensile strength of 1400 MPa in combination with the elongation of 1 % for cast irons.The annual demand for ADI in Belarus is estimated as about 10,000 ton. It is shown that in Belarus, where about 60 industrial enterprises have a foundry and almost every engineering plant has a heat-treatment shop, austempered ductile cast (ADI), which features a high strength, can successfully compete with rolled steel in certain applications.


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