High Strength Ductile Iron Produced by Engineered Cooling: Process Concept

2015 ◽  
Vol 9 (2) ◽  
pp. 21-30 ◽  
Author(s):  
Simon N. Lekakh
Keyword(s):  
Ductile Iron ◽  
High Strength ◽  
Cooling Process

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.

Turning of Austempered Ductile Iron with ceramic tools

2020 ◽  
pp. 095440542095715 ◽  
Author(s):  
A Fernández-Valdivielso ◽  
LN López de Lacalle ◽  
P Fernández-Lucio ◽  
H González
Keyword(s):  
Heat Treatment ◽  
Tool Wear ◽  
Ductile Iron ◽  
High Strength ◽  
Cutting Parameters ◽  
Precise Determination ◽  
Machining Process ◽  
Austempered Ductile Iron ◽  
Machining Time ◽  
Ceramic Tools

Austempered ductile iron castings (ADI) are characterized by the high strength and resistance to fatigue, impact, and wear. ADI mechanical properties are obtained by performing a heat treatment on ductile iron casting. Thus, the so-called ausferrite microstructure is achieved. However, heat treatment significantly affects ductile casting machinability. A precise determination of ADI microstructure, on the one hand, and to choose correct machining process parameters and tool wear control on the other, are essential to optimize cutting processes and for the introduction of ceramic inserts. Ceramics are an alternative to carbide tools. In this paper, ceramic tools for the dry turning of ADI castings are studied. Thus, different technical ceramics were analyzed, identifying the dominant wear mechanism and evolution. Tool wear rate magnitude was determined indirectly by the variation of cutting force along machining time. Finally, different tests helped to study ceramics wear sensitivity with respect to cutting parameters. Mixed ceramics of Al2O3 with TiC showed the best performance, followed by SiAlON ones.

Microstructure and Mechanical Properties of X80/X100 High Deformability Pipeline Steel

2011 ◽  
Vol 399-401 ◽  
pp. 139-143
Author(s):  
Dian Xiu Xia ◽  
De Liang Meng ◽  
Shou Yong An ◽  
Yong Lin Kang
Keyword(s):  
Pipeline Steel ◽  
Large Strain ◽  
High Strength ◽  
Longitudinal Direction ◽  
Granular Bainite ◽  
Dual Phase ◽  
Cooling Process ◽  
Bainite Structure ◽  
Lath Bainite ◽  
High Deformability

In the present study, X80 and X100 grade high deformability pipeline steels have been processed by using TMCP and followed two-stage cooling process. The microstructures of the X80HD (HD, high deformability) and X100HD steels were both characterized by ferrite-bainite dual phase. The grains sizes of ferrite were mostly less than 5μm and the volume fractions were about 20~25% in X80HD and 10~15% in X100HD steel. The bainite structure in X80HD steel was granular bainite (GB); while in X100HD steel large amounts of lath bainite (LB) were also formed besides GB, and bainite grains were much finer. Ferrite-bainite dual phase microstructure has large strain hardenability that resulting high strength and high deformability combination. Both the steels exhibit high strength/toughness in transverse direction and high deformability in longitudinal direction. The X100HD steel with more volume of LB and less volume of PF has higher strength but lower deformability than that of X80HD steel.

A Comparative Assessment of Austempered Ductile Iron as a Substitute in Weight Reduction Applications

2008 ◽  
Author(s):  
Ashwin Polishetty ◽  
Sarat Singamneni ◽  
Guy Littlefair
Keyword(s):  
Ductile Iron ◽  
High Performance ◽  
Material Selection ◽  
Weight Ratio ◽  
Cost Savings ◽  
High Strength ◽  
Good Choice ◽  
Comparative Assessment ◽  
Austempered Ductile Iron ◽  
Machining Characteristics

Manufacturing engineering has had to undergo drastic changes in the approach to material selection in order to meet new design challenges. In the automotive industry, researchers in their effort to reduce emissions and satisfy environmental regulations, have shifted their focus to new emerging materials such as high-strength aluminium alloys, metal matrix composites, plastics, polymers and of late, Austempered Ductile Iron (ADI). ADI is a good choice for design where the criterion is high performance at reduced weight and cost. The unique, ausferrite microstructure gives the material desirable material properties and an edge over other materials. A comparative study of ADI in terms of materials properties and machining characteristics with other materials is desirable to highlight the potential of the material. This paper focuses on a comparative assessment of material and machining characteristics of ADI for different applications. The properties under consideration are machinability, weight and cost savings and versatility. ADI has a higher strength-to-weight ratio than aluminium making it a ready alternative for material selection. In terms of machinability, there are some problems associated with machining of ADI due to its work hardening nature. This paper attempts to identify the possible potential applications of ADI, by critically reviewing specific applications such as machinability, overall economics and service.

Effect of Divorced Eutectic on the Liquation Crack Susceptibility of Al-Cu Alloy

2012 ◽  
Vol 217-219 ◽  
pp. 338-342
Author(s):  
Cheng Gang Yang ◽  
Qiang Zhen ◽  
Ji Jun Xin
Keyword(s):  
High Strength ◽  
Eutectic Solidification ◽  
Heating Process ◽  
Hot Ductility ◽  
Cooling Process ◽  
Liquation Cracking ◽  
Cu Alloy ◽  
Aluminum Alloy 2219 ◽  
Crack Susceptibility ◽  
Strength And Ductility

Hot ductility testing is used to evaluate the liquation cracking susceptibility of high Strength aluminum alloy 2219, the fracture surface of hot ductility samples are inspected by SEM, the results showed that the melting point of α(Al)-CuAl2 divorced eutectic is higher than that of α(Al)- CuAl2 eutectic. The α(Al)- CuAl2 divorced eutectic is prior to melting during heating process and solidification during cooling process, so the BTR of Al-Cu alloy 2219 is narrow. The low liquation cracking susceptible and good weldability of Al-Cu alloy 2219 due to the rapidly recover the strength and ductility in elevated temperature which caused by the α(Al)-CuAl2 divorced eutectic solidification during cooling process.

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