scholarly journals Structural iron with compact forms of graphite

2015 ◽  
Vol 2015 (3) ◽  
pp. 24-29
Author(s):  
Денис Болдырев ◽  
Denis Boldyrev ◽  
Сергей Давыдов ◽  
Sergey Davydov ◽  
Виталий Сканцев ◽  
...  

The identity of the mechanical properties of ductile iron (QP) and cast iron with compact forms of graphite, in particular, with nodular and vermicular graphite (CSWG). Given the fundamental differences in techniques of obtaining QP and CSUG in terms of their labor, material and energy intensity at virtually the identical strength properties shown to be technically and economically preferable for the manufacture of castings of CSWG and other cast iron with a compact form of graphite.

2020 ◽  
Vol 998 ◽  
pp. 42-47
Author(s):  
Alena Pribulová ◽  
Peter Futaš ◽  
Marcela Pokusova

Worldwide production of ductile iron castings reached in year 2017 26,428,148 metric tons, which is 34% of the total weight of all castings made from cast iron. The most significant increase in ductile iron castings was recorded in Slovakia, up to 78.6%. Castings from ductile iron have a very huge utilization thanks their very good foundry and mechanical properties. The current economic situation in all industries forces entrepreneurs and producers to rationalize production and reduce production costs, with a worldwide trend to increase the share of steel scrap, a technology for the production of ductile cast iron. The paper describes the results of research focused on the effect of charge composition, mainly the share of scrap steel on the final properties and structure of ductile iron EN-GJS-500-7 under the operating conditions of foundry. Six melts with different charge composition were made. The samples from all melts were taken and chemical analysis, microstructure analysis and testing on mechanical properties were made on them. The mechanical properties of produced globular cast irons were according with the relevant standard. It is important to mention that there has been a significant increase in strength characteristics in melts in which the carbon content exceeded 4% (CE = 4.7 and 4.8%, respectively).


Author(s):  
Edney Deschauer Rejowski ◽  
Edmo Soares ◽  
Ingo Roth ◽  
Steffen Rudolph

With the increase of combustion loading and the trend to reduce engine size, there is a need for thinner but stronger wet cylinder liners. While most of the current cylinder liners are made of gray cast iron, due to its good tribological behavior, machinability performance and competitive price, alternative casting materials like compact graphite iron, ductile iron and even steel are being considered to cover the future engine demands. In this paper, a new ductile iron (DI) cast material for wet cylinder liners is presented. The material has about 60 and 70% higher limits respectively for tensile stress and fatigue resistance as compared to conventional gray cast irons, but without penalty on the tribological properties. There is also a potential improvement to avoid cavitation on the outside surface due to its higher young modulus, which also equates to a higher stiffness. The tested cylinder liners were induction hardened on the running surface and a slide hone process was used to improve wear and scuffing resistance. The liners were tested in a HDD engine with PCP of 245 bar and showed similar wear as observed with conventional cylinder liners of gray cast iron material. The DI cylinder liners were also tested in an abusive scuffing engine test without any concern. The improved mechanical properties of the described new DI material introduce possibilities to reduce liner wall thickness or increase specific output. The preliminary evaluation in this paper showed that this new material is feasible for HDD diesel engines with PCP up to 250 bar. In cases that the customer needs to increase the bore diameter for output reasons there is the potential to reduce the liner wall thickness up to 25% based on high mechanical properties (UTS, Young Modulus and fatigue strength). In both cases, it’s recommended a FEA analysis to support the new component design.


2010 ◽  
Vol 139-141 ◽  
pp. 235-238
Author(s):  
De Qiang Wei

In this paper, the low alloy bainite ductile cast iron has been obtained by a new heat treatment technique of the step austempering in room-temperature machine oil. The effects of element boron, manganese and copper on structure and mechanical properties of the bainite ductile cast Iron in above-mentioned process are investigated. The phenomenon, hardness lag of the alloyed bainite ductile cast Iron, has been discussed. It shows that after the step austempering in room-temperature machine oil, the hardness will increases with the time. It is found that boron and manganese can increase the hardness and reduce the impact strength while copper can increase the impact strength. The results show that reasonable alloyed elements can improve mechanical properties of the bainite ductile cast Iron. Essentially, hardness lag of the alloyed bainite ductile cast Iron is resulted from solute drag-like effect.


2021 ◽  
Vol 18 (1) ◽  
pp. 1-8
Author(s):  
O.I. Sekunowo ◽  
J.O. Ugboaja ◽  
J.A. Tiamiyu

Production of ductile iron using ferrosilicon-magnesium master alloy in melt treatment is currently fraught with challenges bothering on cost and availability. In this study the suitability of cashew nut shells ash (CNSA) as a viable alternative to magnesium master alloys employed in the treatment of molten cast iron for enhanced mechanical properties was studied. The carbonized CNSA used varied from 2-10 wt. % to treat different heat batches; CA1-CA5 containing varied amount of CNSA, CaO and FeSi in the molten cast iron. The cast samples were subjected to both mechanical characterisation (tensile, hardness and impact) and microstructural analysis using Instron electromechanical machine, impact tester and scanning electron microscope (SEM) coupled with energy dispersive spectroscope (EDS). Results show that the 8 wt. % CNSA addition demonstrated the best mechanical properties comparable to ASTM A536 ferritic ductile cast iron. Specifically, the 8 wt. % CNSA cast samples exhibited 433 MPa tensile strength, 144HRC hardness and ductility of 14.7%. Contributions to improved mechanical properties may be attributed to the development of sufficient fractions of graphite nodules during melt treatment with CNSA. These outcomes are a boost both to the production of quality ductile irons and a cleaner environment. Keywords: Nodularisation, ductile-iron, cashew-nut, ferrosilicon-magnesium alloy, mechanical properties


2014 ◽  
Vol 14 (2) ◽  
pp. 91-94 ◽  
Author(s):  
A. Krzyńska ◽  
A. Kochański

Abstract The results presented in this paper are a continuation of the previously published studies. The results of hest treatment of ductile iron with content 3,66%Si and 3,80% Si were produced. The experimental castings were subjected to austempering process for time 30, 60 and 90 minutes at temperature 300°C. The mechanical properties of heat treated specimens were studied using tensile testing and hardness measurement, while microstructures were evaluated with conventional metallographic observations. It was again stated that austempering of high silicone ferritic matrix ductile iron allowed producing ADI-type cast iron with mechanical properties comparable with standard ADI.


2013 ◽  
Vol 13 (1) ◽  
pp. 81-88
Author(s):  
A. Kowalskia ◽  
S. Kluska-Nawarecka ◽  
K. Regulski

Abstract ADI subjected to austenitising at intercritical temperatures contains in its matrix the precipitates of pre-eutectoid ferrite. Studies were carried out on the ductile iron of the following chemical composition: C = 3,80%, Si = 2,30%, Mn = 0,28%, P = 0,060%, S = 0,010%, Mg = 0,065%, Ni = 0,60%, Cu = 0,70%, Mo = 0,21% This cast iron was austenitised at three different temperatures, i.e. 800, 815 and 830oC and austempered at 360 and 380oC. For each variant of the cast iron heat treatment, the mechanical properties, i.e. YS, TS, EL and Hardness, were measured, and structure of the matrix was examined. Higher plastic properties were obtained owing to the presence of certain amount of pre-eutectoid ferrite. The properties were visualised using fuzzy logic model in a MATLAB. software.


2011 ◽  
Vol 183-185 ◽  
pp. 367-371
Author(s):  
Chang Long Li ◽  
Liang Dong ◽  
Xiao Min Sun

Using the invention patent technology (patent number ZL2005 1 0131175.7), the impact on environment in ductile iron production was studied. By using the environmentally friendly and adjustable spheroidizing equipment, the spheroidization can proceed in a completely closed state. The smoke with the spheroidization is eliminated just as the production of inoculated cast iron. The pressure in the ladle can be automatically adjusted from 0KPa to 8.62KPa and the absorption rate of elements is improved. Without sacrificing the spheroidizing level and mechanical properties, the amount of added nodularizer can be decreased by 0.2%-0.5%. Saving the costs and protecting the environment.


Open Physics ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 566-574
Author(s):  
Yu Zhang ◽  
Erjun Guo ◽  
Liping Wang ◽  
Yicheng Feng ◽  
Sicong Zhao ◽  
...  

Abstract With the continuous development of metal manufacturing technology, high-strength and high-hardness ductile iron materials have excellent comprehensive performance. Many performance indexes are comparable to those of alloy steels, and they have excellent casting properties. Many large-scale parts produced by cast steel are slowly being replaced by this material. Ductile iron is obtained by a spheroidizing treatment and inoculation to obtain spheroidal graphite. The mechanical properties of cast iron have been effectively improved, especially plasticity and toughness, and the strength obtained is higher than that of carbon steel. Ductile iron has the properties of iron and the properties of steel. It is a new type of engineering material with high plasticity, strength, corrosion resistance, and wear-resistance. Because of its excellent performance, it has been successfully used to cast parts with high-stress conditions, high strength, toughness and wear resistance. Due to the small splitting effect of ductile iron on the metal matrix, the stress concentration is effectively eliminated. Therefore, the matrix structure of ductile cast iron is changed by heat treatment, thereby improving its mechanical properties and the damping performance of the material itself. Through a heat treatment process experiment of ductile iron, the related process and technical measures of damping performance in the heat treatment production process are obtained.


2015 ◽  
Vol 4 (4) ◽  
pp. 526
Author(s):  
Adebayo Badmos ◽  
Kelvin Fakehinde

Multiple inoculation of ductile iron and the effects on the structure and mechanical properties have being investigated. Samples of ductile iron were produced with inoculation carried out either once or twice and with different materials as inoculants. Ferrosilicon was used for the primary inoculation and either ferrosilicon or nickel-ferrosilicon for the secondary inoculation. It is observed that the nodules produced are more and finer with multiple inoculations and the effect is more pronounced with nickel-ferrosilicon as the secondary inoculant. Multiple inoculations produce an increase in the hardness of ductile iron when ferrosilicon is used as the secondary inoculant while a decrease in the hardness is observed with nickel-ferrosilicon despite the finer nodules. This is explained by the fact that nickel enhances graphitization in cast iron thereby depleting carbon in the matrix and making the cast iron weaker but with more nodules.


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