scholarly journals Increasing the Wear Resistance of Marine Diesel Engines Elements Made of Ductile Iron

Naše more ◽  
2021 ◽  
Vol 68 (3) ◽  
pp. 150-156
Author(s):  
Zoran Veljačić ◽  
◽  
Krešimir Grilec
Keyword(s):  
Wear Resistance ◽  
Cast Iron ◽  
Ductile Iron ◽  
Shot Peening ◽  
Lower Bainite ◽  
Ductile Cast Iron ◽  
Metallographic Analysis ◽  
Cast State ◽  
Soft Phase ◽  
The Matrix

This paper examines the influence of austempering and shot peening on the wear resistance of ductile iron. Samples for further testing were made from mechanically processed casts. The hardness and microstructure of ductile iron were examined on the prepared samples. Metallographic analysis of ductile cast iron samples in the cast state determined the pearlitic-ferritic structure of the matrix characteristic of this type of cast iron. Pearlite predominates in the structure, and the rest consists of ferrite and graphite nodules. The samples were then austempered. The isothermal conversion was 240 °C. After austempering, the hardness was measured and the microstructure was characterized, and the changes that occurred in relation to the heat-treated ductile iron were studied. Austempering created a new austempered structure, harder than that in the cast state, which led to improved mechanical properties. A needle-like structure of lower bainite (ADI) with high-carbon austenite, untransformed austenite, martensite and graphite nodules was achieved. The selected parameters of the shot peening process deformed the surface of the ADI and achieved a mostly martensitic structure without the presence of a soft phase, which increased resistance to abrasion. Additional hardening of the substrate by the shot peening process resulted in a composite material with the properties of comparative steel parts, which are lighter, cheaper and easier to manufacture, more resistant to wear and quieter in operation. Such material should have an even wider application in mechanical engineering, and thus in the construction of marine machinery and plants.

scholarly journals Effect of the Carbides and Matrix on the Wear Resistance of Nodular Cast Iron

2013 ◽  
Vol 13 (3) ◽  
pp. 25-29
Author(s):  
G. Gumienny
Keyword(s):  
Wear Resistance ◽  
Cast Iron ◽  
Quartz Sand ◽  
Nodular Cast Iron ◽  
Lower Bainite ◽  
Abrasive Wear Resistance ◽  
Surface Fraction ◽  
The Matrix ◽  
Unit Pressure ◽  
Abrasive Paper

Abstract This paper presents the results of the abrasive wear resistance of selected types of nodular cast iron, including ADI, cooperating with quartz sand and 100 grit abrasive paper. It has been shown that carbides in nodular cast iron cause an increase in wear resistance of 6 to 12% depending on the surface fraction of the carbides and type of the matrix. For the same unit pressure the mass loss of the cast iron cooperating with quartz sand is many times larger than the cast iron cooperating with abrasive paper. For both abrasives the highest wear resistance showed nodular cast iron with upper and lower bainite and carbides.

scholarly journals Influence of Technological Parameters of Furane Mixtures on Shrinkage Creation in Ductile Cast Iron Castings

2014 ◽  
Vol 59 (3) ◽  
pp. 1037-1040 ◽  
Author(s):  
I. Vasková ◽  
M. Hrubovčáková ◽  
J. Malik ◽  
Š. Eperješi
Keyword(s):  
Cast Iron ◽  
Ductile Iron ◽  
Ductile Cast Iron ◽  
Gating System ◽  
Technological Parameters ◽  
Iron Castings ◽  
Steel Castings ◽  
The Impact ◽  
Very High ◽  
Great Development

Abstract Ductile cast iron (GS) has noticed great development in last decades and its boom has no analogue in history humankind. Ductile iron has broaden the use of castings from cast iron into areas, which where exclusively domains for steel castings. Mainly by castings, which weight is very high, is the propensity to shrinkage creation even higher. Shrinkage creation influences mainly material, construction of casting, gating system and mould. Therefore, the main realized experiment was to ascertain the influence of technological parameters of furane mixture on shrinkage creation in castings from ductile iron. Together was poured 12 testing items in 3 moulds forto determine and compare the impact of various technological parameters forms the propensity for shrinkage in the casting of LGG.

Analysis of the Structure and Abrasive Wear Resistance of White Cast Iron with Precipitates of Carbides

2013 ◽  
Vol 58 (3) ◽  
pp. 973-976 ◽  
Author(s):  
D. Kopyciński ◽  
M. Kawalec ◽  
A. Szczęsny ◽  
R. Gilewski ◽  
S. Piasny
Keyword(s):  
Wear Resistance ◽  
Cast Iron ◽  
Abrasive Wear ◽  
Metal Matrix ◽  
White Cast Iron ◽  
Abrasive Wear Resistance ◽  
Operating Conditions ◽  
Metallographic Analysis ◽  
Abrasive Hardness ◽  
Resistance Tests

Abstract The resistance of castings to abrasive wear depends on the cast iron abrasive hardness ratio. It has been anticipated that the white cast iron structure will be changed by changing the type of metal matrix and the type of carbides present in this matrix, which will greatly expand the application area of castings under the harsh operating conditions of abrasive wear. Detailed metallographic analysis was carried out to see the structure obtained in selected types of white cast iron, i.e. with additions of chromium and vanadium. The study compares the results of abrasive wear resistance tests performed on the examined types of cast iron.

Advances in Carbidic Austempered Ductile Iron (CADI) – a wear resistant material

2021 ◽  
Vol 14 ◽  
Author(s):  
Lakshmiprasad Maddi ◽  
Ajay Likhite
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
Cast Iron ◽  
Ductile Iron ◽  
Viable Alternative ◽  
Austempered Ductile Iron ◽  
Resistant Material ◽  
Fine Carbide ◽  
Matrix Graphite ◽  
Malleable Cast

Background: Ductile irons provide a more viable alternative for malleable cast iron in areas that do not demand extreme wear resistance. Austempering of ductile irons was a well researched area in the last two decades. Attempts to further improve the wear resistance led to the development of Carbidic austempered ductile iron (CADI), wherein the carbides contribute to wear resistance. Combination of ausferritic matrix, graphite nodules, and carbides (eutectic and alloy) symbolizes the microstructure of CADI. Methods: Two principal approaches adopted by the researchers to change the microstructure are (i) addition of carbide forming elements (ii) heat treatment (s). Results: Both the above methods result in the refinement of graphite nodules, carbide precipitations, along with fine ausferrite. Conclusion: Improvement in hardness, toughness and wear resistance was observed largely as a consequence of fine carbide precipitations and formation of martensite.

Influence of Charge Composition on EN-GJS-500-7 Ductile Iron Properties in Foundry Operating Conditions

2020 ◽  
Vol 998 ◽  
pp. 42-47
Author(s):  
Alena Pribulová ◽  
Peter Futaš ◽  
Marcela Pokusova
Keyword(s):  
Mechanical Properties ◽  
Cast Iron ◽  
Ductile Iron ◽  
Ductile Cast Iron ◽  
Operating Conditions ◽  
Production Costs ◽  
Steel Scrap ◽  
Charge Composition ◽  
Iron Castings ◽  
Worldwide Production

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).

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.

Carbidic Bainitic and Ausferritic Ductile Cast Iron

2013 ◽  
Vol 58 (4) ◽  
pp. 1053-1058 ◽  
Author(s):  
G. Gumienny
Keyword(s):  
Cast Iron ◽  
Solid State ◽  
Thermal Effects ◽  
Metal Matrix ◽  
Lower Bainite ◽  
Ductile Cast Iron ◽  
Iron Metal ◽  
Derivative Analysis ◽  
Upper Bainite ◽  
Matrix Components

Abstract This article presents new kinds of carbidic ductile cast iron with different microstructures of the metal matrix. This cast iron was obtained using the Inmold method nodularisation which guarantees strong refining of graphite and the metal matrix components. A different microstructure of the metal matrix of the cast iron was obtained without any thermal treatment (unwrought) by a suitable composition of alloy additives. It was shown that by adding molybdenum, chromium, nickel and copper it is possible to obtain in the cast iron metal matrix consisting of upper bainite, its mixture with lower bainite or ausferrite in the casts with the wall thickness of 3/25 mm. The process of cast iron crystallization is presented and described with the help of the thermal and derivative analysis (TDA) curves. It also shows the thermal effects from transformation of austenite in solid state.

Study on the Wear Resistance of Cast-Oozing Different Content of WC

2011 ◽  
Vol 239-242 ◽  
pp. 990-993
Author(s):  
Ai Qin Wang ◽  
Shu Li Wang ◽  
Jing Pei Xie
Keyword(s):  
Wear Resistance ◽  
Cast Iron ◽  
Iron Layer ◽  
Wear Properties ◽  
Metallurgical Bonding ◽  
The Matrix ◽  
Different Content

In this paper, the WC and high-Cr Cast Iron layer were obtained on the surface of ZG30Cr steel by casting-penetrating process, the organization and wear properties of penetrating layer were studied. The results show that the layer is dense, without pores, slag and other defects, the penetrating layer and substrate are metallurgical bonding. When 20 %WC and 80 % Cr-Fe with are added to permeability agent, the penetrating layer has the best wear resistance, is 11.3 times the matrix materials.

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