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 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 Copper Enrichment around Graphite in Cu-added High-Strength Spheroidal Graphite Cast Iron

Materia Japan ◽  
2009 ◽  
Vol 48 (12) ◽  
pp. 624-624 ◽  
Author(s):  
Yasuhide Ishiguro ◽  
Kenji Ichino ◽  
Hideto Takasugi
Keyword(s):  
Cast Iron ◽  
High Strength ◽  
Spheroidal Graphite ◽  
Spheroidal Graphite Cast Iron ◽  
Graphite Cast Iron

ISO 185/JL/350

Alloy Digest ◽  
2021 ◽  
Vol 70 (9) ◽  
Keyword(s):  
Thermal Conductivity ◽  
Tensile Strength ◽  
Cast Iron ◽  
Gray Cast Iron ◽  
High Strength ◽  
Heat Treating ◽  
Gray Cast ◽  
Spheroidal Graphite ◽  
Cast Irons ◽  
Test Pieces

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.

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.

On a possibility of replacing grey cast iron for manufacturing cast elements of electrolyzer gas collecting bell

2021 ◽  
Vol 77 (9) ◽  
pp. 1063-1070
Author(s):  
A. A. Usol’tsev ◽  
N. A. Kozyrev ◽  
S. V. Knyazev ◽  
A. I. Kutsenko ◽  
A. R. Mikhno
Keyword(s):  
Corrosion Resistance ◽  
Cast Iron ◽  
Heat Resistance ◽  
High Strength ◽  
Grey Cast Iron ◽  
Simultaneous Formation ◽  
Metal Base ◽  
Spherical Graphite ◽  
Grey Cast ◽  
Graphite Inclusions

The main process leading to the destruction of the cast elements of gas-collection bell of electrolyzer, made of grey cast iron, is the oxidation of iron by oxygen, SO2 gas and sulfur vapors to form magnetite, hematite and pyrrhotin. The simultaneous formation of iron oxides and sulfides does not prevent further corrosion, since scale is formed with a loose structure that does not have protective properties. Reducing the length of the interfacial boundaries inside the material of the cast enables to reduce the rate of corrosion destruction, which can be achieved by modifying the cast iron to change the shape of graphite inclusions, i.e. obtaining high-strength cast iron with a spherical shape of graphite inclusions. However, the obtaining spherical graphite in cast iron using magnesium modification does not exclude the access of aggressive gases to the surface of the products and the possibility of their diffusion along the grain boundaries. It was shown that alloying can be an alternative, which leads not only to the exclusion of lamellar secretions of graphite in the structure of cast iron, but also to the formation of surface oxide layers based on the alloying element preventing the corrosion. Alloying with chromium gives cast iron high abrasive resistance due to the presence of a carbide component in the structure, as well as corrosion resistance due to the alloying of the metal base, heat resistance due to increasing the electrochemical potential of the metal base and creating a strong neutral oxide film on the surface of the castings, heat resistance, etc. An experimental comparative analysis of the corrosion resistance of cast iron used for manufacturing of gas collecting bell of electrolyzers showed that chromic cast iron ЧХ3 has a higher corrosion resistance than high-strength cast iron with spherical graphite ВЧ50 and much higher than grey cast iron with lamellar graphite. However, chromic cast iron ЧХ3 has low casting properties, is very sensitive to the cooling rate and has a large heterogeneity in structure, which makes it difficult to use it for the manufacture of gas collecting bell of electrolyzers.

Microstructure and Mechanical Properties of High Strength Low Alloy Steel Q550D

2021 ◽  
Vol 1035 ◽  
pp. 424-429
Author(s):  
Fang Po Li ◽  
Ning Li ◽  
Xian Lin Wang ◽  
Ming Hua Liang
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Oil And Gas ◽  
High Strength ◽  
Service Performance ◽  
Low Alloy Steel ◽  
Micro Structure ◽  
Gas Drilling ◽  
Drilling Equipment ◽  
Equipment Manufacture

Drilling equipment is the key of oil and gas drilling development. Its manufacturing quality and service performance have important influence on oil and gas drilling development safety. The application of high strength grade steel plays an important role in improving drilling equipment manufacturing level and service performance. In this paper, the chemical composition, microstructure, tensile properties, impact properties and hardness of TMCP Q550D and Q-T Q550D high-strength low-alloy steel were tested and compared, and the application feasibility for drilling equipment manufacture was analyzed comprehensively. The experimental results show that the mechanical properties of Q550D by two different methods were obviously higher than the requirement of national standard. Q550D steel had excellent plasticity and toughness, which meets the requirement of drilling equipment manufacture. The main difference between different steel lied in their chemical composition and micro-structure. Carbon content of TMCP Q550D steel plate was lower than that of QT Q550D, and TMCP Q550 was mainly depend on TMCP technology and micro-alloy elements, whose micro-structure was mainly granular bainite. Q-T Q550D was mainly depend on Q-T technology, and its microstructure was tempered sorbite with obvious banded structure and slightly low toughness.

Bainitic high-strength cast iron with spheroidal graphite (review)

1991 ◽  
Vol 33 (10) ◽  
pp. 762-771
Author(s):  
B. I. Voronenko ◽  
Yu. I. Romatovskii
Keyword(s):  
Cast Iron ◽  
High Strength ◽  
Spheroidal Graphite

Spun Steel Pipes for the Offshore Industry

1983 ◽  
Vol 105 (1) ◽  
pp. 97-102 ◽  
Author(s):  
A. Royer ◽  
B. Dumas ◽  
M. Gantois
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Centrifugal Casting ◽  
High Strength ◽  
Controlled Rolling ◽  
Climatic Conditions ◽  
Casting Technique ◽  
Steel Pipes ◽  
Potential Applications ◽  
Offshore Industry

Many parts either for sea-line pipes as “buckle” or “crack arrestor,” or for structures may require the use of wall tubular products with high mechanical properties. Such heavy-wall pipes may be produced by centrifugal casting. Two Mn-Mo steels have been developed for medium-wall pipes (e≤35 mm) to be used under very severe climatic conditions: an acicular ferritic steel, a pearlite reduced steel produced by controlled rolling techniques [1, 2, 3]. More alloyed chemical composition and heat-treatments are needed to produce heavy-wall pipes. Then, production of such pipes is more difficult and sometimes impossible. Observations made on controlled-rolled Mn-Mo steel led to a better understanding of the influence of metallurgical structures and chemical composition on steel characteristics. Similar metallurgical structures can only be reached via other routes, for example centrifugal-casting of steel associated with heat-treatment, lead to the production of heavy-wall pipes with high strength and suitable transition temperature. After a brief description of the centrifugal casting technique, we introduce the grades developed for heavy-wall pipes with yield strength up to 100,000 psi. The mechanical properties, Battelle, fatigue, static bending, C.O.D., weldability, etc., of Centrishore II are given and compared to other materials. Possible offshore applications and other potential applications of parts produced by centrifugal casting are described.

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