scholarly journals Research and Analysis of the Effect of Heat Treatment on Damping Properties of Ductile Iron

Open Physics ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 566-574
Author(s):  
Yu Zhang ◽  
Erjun Guo ◽  
Liping Wang ◽  
Yicheng Feng ◽  
Sicong Zhao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Wear Resistance ◽  
Cast Iron ◽  
Ductile Iron ◽  
Cast Steel ◽  
High Stress ◽  
High Strength ◽  
Spheroidal Graphite ◽  
High Plasticity

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.

scholarly journals Machinability and related properties of austempered ductile iron: A review

2018 ◽  
Vol 12 (4) ◽  
pp. 4180-4190
Author(s):  
Ananda Hegde ◽  
Sathyashankara Sharma ◽  
Gowri Shankar M. C
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Wear Resistance ◽  
Ductile Iron ◽  
High Hardness ◽  
Austempered Ductile Iron ◽  
Spheroidal Graphite ◽  
Light Weight ◽  
Sg Iron

When the ductile iron which is also known as Spheroidal Graphite (SG) iron, is subjected to austempering heat treatment, the material is known as austempered ductile iron (ADI). This material has good mechanical properties and has various applications in different fields. This revolutionary material with its excellent combination of strength, ductility, toughness and wear resistance has the potential to replace some of the commonly used conventional materials such as steel, aluminium and other light weight alloys as it offers production advantage as well. One of the problems encountered during manufacturing is machining of ADI parts owing to its high hardness and wear resistance. Many researchers over a period of time have reported the machinability aspects of the ADI. This paper presents a review on the developments made on the machinability aspects of ADI along with other mechanical properties.

scholarly journals Effect of Heat Treatment Parameters on the Toughness of Unalloyed Ausferritic Ductile Iron

2016 ◽  
Vol 16 (2) ◽  
pp. 79-84 ◽  
Author(s):  
E. Guzik ◽  
M. Sokolnicki ◽  
A. Nowak
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Cast Iron ◽  
Ductile Iron ◽  
High Strength ◽  
Process Window ◽  
Austenitizing Temperature ◽  
Plastic Properties ◽  
Alloyed Cast Iron ◽  
Nodular Graphite

Abstract Studies were carried out to determine the effect of heat treatment parameters on the plastic properties of unalloyed ausferritic ductile iron, such as the elongation and toughness at ambient temperature and at – 60 °C. The effect of austenitizing temperature (850, 900 and 950°C) and ausferritizing time (5 - 180 min.) at a temperature of 360°C was also discussed. The next step covered investigations of a relationship that is believed to exist between the temperature (270, 300, 330, 360 and 390 °C) and time (5, 10, 30, 60, 90, 120, 150, 180, 240 min.) of the austempering treatment and the mechanical properties of unalloyed ausferritic ductile iron, when the austenitizing temperature is 950°C. The “process window” was calculated for the ADI characterized by high toughness corresponding to the EN-GJS-800-10-RT and EN-GJS-900-8 grades according to EN-PN 1564 and to other high-strength grades included in this standard. Low-alloyed cast iron with the nodular graphite is an excellent starting material for the technological design of all the ausferritic ductile iron grades included in the PN-EN-1624 standard. The examined cast iron is characterized by high mechanical properties stable within the entire range of heat treatment parameters.

scholarly journals Ausferritic (bainitic) cast iron: Harmonization of international standard ISO 17804 in application to the conditions of Belarus

2021 ◽  
pp. 56-72
Author(s):  
A. I. Pokrovskii ◽  
B. B. Khina ◽  
O. A. Tolkacheva
Keyword(s):  
Tensile Strength ◽  
Cast Iron ◽  
Ductile Iron ◽  
High Strength ◽  
State Committee ◽  
Spheroidal Graphite ◽  
Cast Irons ◽  
International Standard ◽  
Industrial Enterprises ◽  
State Organizations

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.

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.

Effect of Different Heat Treatments on Microstructure and Mechanical Properties of the Martensitic Gx12CrMoVNbN9-1 Cast Steel / Wpływ Parametrów Obróbki Cieplnej Na Mikrostrukture I Własciwosci Mechaniczne Martenzytycznego Staliwa Gx12CrMoVNbn9-1

2013 ◽  
Vol 58 (1) ◽  
pp. 25-30 ◽  
Author(s):  
G. Golanski ◽  
J. Słania
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Impact Energy ◽  
Cast Steel ◽  
Lath Martensite ◽  
High Strength ◽  
Strength Properties ◽  
Microstructure And Mechanical Properties ◽  
Quenching And Tempering ◽  
Very High

The paper presents a research on the influence of multistage heat treatment with the assumed parameters of temperature and time on the microstructure and mechanical properties of high-chromium martensitic GX12CrMoVNbN9-1 (GP91) cast steel. In the as-cast state GP91 cast steel was characterized by a microstructure of lath martensite with numerous precipitations of carbides of the M23C6, M3C and NbC type, with its properties higher than the required minimum. Hardening of the examined cast steel contributes to obtaining a microstructure of partly auto-tempered martensite of very high strength properties and impact strength KV on the level of 9-15 J. Quenching and tempering with subsequent stress relief annealing of GP91 cast steel contributed to obtaining the microstructure of high-tempered lath martensite with numerous precipitations of the M23C6 and MX type of diverse size. The microstructure of GP91 cast steel received after heat treatment was characterized by strength properties (yield strength, tensile strength) higher than the required minimum and a very high impact energy KV. It has been proved that GP91 cast steel subject to heat treatment No. 2 as a result of two-time heating above the Ac3 temperature is characterized by the highest impact energy.

The Influence of Boron on Structure and Mechanical Properties of Bainite Ductile Iron in the Step Austempering in Room Temperature Machine Oil

2010 ◽  
Vol 139-141 ◽  
pp. 235-238
Author(s):  
De Qiang Wei
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Cast Iron ◽  
Impact Strength ◽  
Ductile Iron ◽  
Room Temperature ◽  
Solute Drag ◽  
Ductile Cast Iron ◽  
Treatment Technique ◽  
The Impact

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.

scholarly journals Effect of Heat-treatment Parameters of Cast Iron GJS-X350NiMnCu7-3-2 on its Structure and Mechanical Properties

2017 ◽  
Vol 17 (1) ◽  
pp. 121-126 ◽  
Author(s):  
D. Medyński ◽  
A. Janus ◽  
S. Zaborski
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Cast Iron ◽  
High Hardness ◽  
Spheroidal Graphite ◽  
Air Cooling ◽  
Material Hardness ◽  
The Matrix ◽  
Lower Material

Abstract The paper presents influence of soaking parameters (temperature and time) on structure and mechanical properties of spheroidal graphite nickel-manganese-copper cast iron, containing: 7.2% Ni, 2.6% Mn and 2.4% Cu. Raw castings showed austenitic structure and relatively low hardness (150 HBW) guaranteeing their good machinability. Heat treatment consisted in soaking the castings within 400 to 600°C for 2 to 10 hours followed by air-cooling. In most cases, soaking caused changes in structure and, in consequence, an increase of hardness in comparison to raw castings. The highest hardness and tensile strength was obtained after soaking at 550°C for 6 hours. At the same time, decrease of the parameters related to plasticity of cast iron (elongation and impact strength) was observed. This resulted from the fact that, in these conditions, the largest fraction of fine-acicular ferrite with relatively high hardness (490 HV0.1) was created in the matrix. At lower temperatures and after shorter soaking times, hardness and tensile strength were lower because of smaller degree of austenite transformation. At higher temperatures and after longer soaking times, fine-dispersive ferrite was produced. That resulted in slightly lower material hardness.

scholarly journals Technological pecularities of producing cast iron with spherical graphite using a fast-cooled copper-magnesium ligature

2020 ◽  
pp. 15-21
Author(s):  
A. G. Slutsky ◽  
I. L. Kulinich ◽  
V. A. Sheinert ◽  
V. A. Stefanovich ◽  
R. E. Trubitsky ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cast Iron ◽  
Chemical Composition ◽  
Magnesium Alloys ◽  
High Strength ◽  
Favorable Effect ◽  
Maximum Effect ◽  
Spheroidal Graphite ◽  
Graphite Phase ◽  
Spherical Graphite

Various modifiers are used for non-furnace processing of cast iron. Some of them are designed for inoculating modification, which improves mechanical properties and eliminates the appearance of whiteness in castings, while others are designed for spheroidizing processing, in particular for producing cast iron with spherical and vermicular graphite. Some have both spheroidizing and inoculating properties. The main part of inoculating and spheroidizing modifiers is made on iron-silicon, Nickel and copper bases.In addition to the chemical composition, the size of the modifier particles, as well as their shape, are of great importance for modification. The optimal size of the fraction depends significantly on the non-furnace processing technology. Thus, for the larger the bucket and the longer the casting the longer the modification effect is required. One of the methods to achieve this is to increase the particle size of the modifier to 50 mm. When intraform processing of cast iron with spherical and vermicular graphite, magnesium-containing modifiers have strict limits on the upper size (4...5 mm), and in addition, the content of small fractions (less than 0.6...1 mm) is not allowed.The use of «heavy» magnesium-containing ligatures for spheroidizing modification of cast iron in order to obtain higher physical and mechanical properties has scientific and practical interest. Numerous studies show that for maximum effect the formation of the structure of the spheroidal graphite, dispersed pearlite metallic base of SGI (spheroidal graphite iron) relevant question is not only selection of the chemical composition of magnesium alloys, but also of the fractional composition, as well as effective method of input into the liquid melt.The purpose of this work was to study the technological features of obtaining cast iron with spherical graphite by bucket modification of copper-magnesium ligature.The researchers used a Leo–1420 scanning microscope, a Polam l-213 optical microscope, and a VEGA II LMU electron microscope with an INCA ENERGY 350 microanalyzer. High-speed induction melting plant, a set of equipment for analyzing the technological and mechanical properties of high-strength cast iron were used.Earlier experimental studies have shown the real possibility of obtaining in the laboratory a «heavy» copper-magnesium alloys as the alloying of magnesium metal with copper, followed by rapid cooling with use of rolling and plastic deformation of powder alloys. Analysis of test results of samples of such alloys showed that it depends on the value of its additives into liquid iron in the structure of formed graphite phase in compacted and globular form. At the same time, the metal base of cast iron is additionally alloyed with copper, which has a favorable effect on the strength characteristics of SGI.However, an urgent problem is the possibility of the appearance of a cementite phase in the structure of high-strength cast iron as a result of its increased supercooling due to the process of spheroidization of the graphite phase. This phenomenon is compounded by the fact that the copper-magnesium ligature, in contrast to the «light» ligature, does not contain silicon active graphitizer. This feature must be taken into account when obtaining high-strength cast iron of high grades.

scholarly journals Effect of silicon carbide modifiers on the physical-mechanical properties of gray cast iron and cast iron with spheroidal graphite

2021 ◽  
Vol 340 ◽  
pp. 01006
Author(s):  
Vladimir A. Poluboyarov ◽  
Anatoliy N. Cherepanov ◽  
Viktor A. Kuznetsov ◽  
Zoya A. Korotaeva ◽  
Alexander A. Zhdanok
Keyword(s):  
Mechanical Properties ◽  
Silicon Carbide ◽  
Wear Resistance ◽  
Cast Iron ◽  
Gray Cast Iron ◽  
Term Treatment ◽  
Gray Cast ◽  
Spheroidal Graphite ◽  
Short Term Treatment ◽  
Maximal Increase

The influence of mechanochemically produced modifiers on the properties of cast iron at out-of-furnace modification has been studied. Short-term treatment in mechanochemical activators makes it possible to produce composite modifiers, which are wetted with iron melts, are uniformly distributed therein and effectively influence the crystallization processes. The effect of a modifier based on silicon carbide and chromium (as a protector metal) on the physical-mechanical properties of gray cast-iron and cast-iron with spheroidal graphite is considered. The introduction of SiC in the amount of 0.01-0.1 wt.% into gray cast iron causes the formation of mainly perlitic structure and, as a consequence, an increase in strength, hardness and wear resistance. For SiC content 0.1 wt.%, the tensile strength of GG-15 samples increased by 22.7%, GG-25 by 8%. The maximal increase in the hardness is observed for SiC concentration: for GG-15 – 0.1, for GG-25 – 0.01 wt.%. The GG-25 sample with 0.1 wt.% SiC exhibited the highest wear resistance. The introduction of SiC (0.01 – 0.1 wt.%) into cast iron with spheroidal graphite causes an increase in ferrite content, which promotes a substantial increase in impact viscosity and wear resistance (the highest wear resistance is observed with the introduction of 0.05 wt.% SiC).

scholarly journals Alloyed White Cast Iron with Precipitates of Spheroidal Vanadium Carbides VC

2012 ◽  
Vol 12 (4) ◽  
pp. 95-100 ◽  
Author(s):  
M. Kawalec ◽  
M. Górny
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Cast Iron ◽  
Master Alloy ◽  
Eutectic Composition ◽  
White Cast Iron ◽  
Base Alloy ◽  
Cast Steel ◽  
Abrasive Wear Resistance ◽  
Vanadium Carbides

Abstract The paper presents the results of tests on the spheroidising treatment of vanadium carbides VC done with magnesium master alloy and mischmetal. It has been proved that the introduction of magnesium master alloy to an Fe-C-V system of eutectic composition made 34% of carbides crystallise in the form of spheroids. Adding mischmetal to the base alloy melt caused 28% of the vanadium carbides crystallise as dendrites. In base alloy without the microstructure-modifying additives, vanadium carbides crystallised in the form of a branched fibrous eutectic skeleton. Testing of mechanical properties has proved that the spheroidising treatment of VC carbides in high-vanadium cast iron increases the tensile strength by about 60% and elongation 14 - 21 times, depending on the type of the spheroidising agent used. Tribological studies have shown that high-vanadium cast iron with eutectic, dendritic and spheroidal carbides has the abrasive wear resistance more than twice as high as the abrasion-resistant cast steel.

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