Conditions for notch strength to be higher than static tensile strength in high–strength ductile cast iron

2019 ◽  
Vol 206 ◽  
pp. 75-88 ◽  
Author(s):  
Tomohiro Ikeda ◽  
Nao–Aki Noda ◽  
Yoshikazu Sano
Alloy Digest ◽  
2021 ◽  
Vol 70 (9) ◽  

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.


Author(s):  
A. I. Pokrovskii ◽  
B. B. Khina ◽  
O. A. Tolkacheva

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.


Author(s):  
Masaaki Kimura ◽  
Akira Yoneda ◽  
Masahiro Kusaka ◽  
Koichi Kaizu ◽  
Kazuhiro Hayashida ◽  
...  

Abstract To obtain dissimilar joint for easily making multi-material structures, the characteristics of friction welded joint between ductile cast iron (FCD400) and 5052 Al alloy (A5052) was investigated. The relatively high tensile strength of joint was obtained when that was made with a friction speed of 27.5 s−1, a friction pressure of 20 MPa, a friction time of 1.5 s, and a forge pressure of 270 MPa, respectively. However, this joint had approximately 77% in the tensile strength of the A5052 base metal and that was fractured at the weld interface. Although the weld interface had no intermetallic compound layer, the fractured surface at the A5052 side had some graphite particles that were supplied from the FCD400 side. To improve the joint strength, the graphite particles were reduced from the weld faying surface at the FCD400 side by decarburization treatment. The joint had approximately 96% in the tensile strength of the A5052 base metal and that was fractured between the A5052 side and the weld interface. The joint with high tensile strength as well as the possibility improving the fractured point of that were obtained when those were made with opportune friction welding condition and no graphite particles at the weld faying surface of the FCD400 side.


2010 ◽  
Vol 457 ◽  
pp. 79-83 ◽  
Author(s):  
Mitsuharu Takita

Semi-solid metal processing with the cooling plate technique is one of the key technologies for producing advanced materials. The multitude of cast iron families with their wide range of mechanical properties, and relatively low costs combined with the advantage of semi-solid processing allow production of high quality cast components from cast iron. The effect of semi-solid processing using the cooling plate technique on the microstructure and the properties of cast iron is studied. The investigated material is hypo-eutectic, hyper-eutectic gray iron, compacted graphite and ductile cast iron. The results indicated that the microstructure (primary austenite and graphite) becomes finer and more globular by increasing the fraction of solid. The tensile strength of semi-solid processed cast iron is relatively high compared with ordinary cast iron. The values of both the tensile strength and the elongation depend on the fraction of solid. The total fracture strength is observed to depend on the graphite morphology as well as the matrix contribution that mainly depends on fraction of solid. The wear resistance and damping capacity of cast iron were investigated as a function of the relative amount of primary fraction of solid.


2019 ◽  
Vol 55 (2) ◽  
pp. 283-293 ◽  
Author(s):  
E. Colin-García ◽  
A. Cruz-Ramírez ◽  
G. Reyes-Castellanos ◽  
J.A. Romero-Serrano ◽  
R.G. Sánchez-Alvarado ◽  
...  

The effect of the casting modulus on the distribution and features of graphite in hypo-eutectic ductile iron unalloyed and alloyed with nickel (0.88 wt %) was studied. The cooling rate of the casting plates of 25.4, 12.7 and 8.5 mm in thickness with a casting modulus of 6.87, 4.46 and 3.31 mm, respectively promotes several microstructural changes, such as cementite precipitation and a noticeable nodule count increment. The nickel addition suppressed the cementite formation and improved the nodule count and nodularity for the three casting modulus evaluated. The nickel addition increased the nodule count in 69, 67 and 128 % for the modulus of 3.31, 4.46 and 6.87 mm, respectively, regarding the unalloyed ductile iron. It was found that the biggest casting modulus produced the biggest nodules with the lowest nodule count for both ductile cast irons. Further to the improvements in the graphite features, the nickel addition allowed to keep almost constant the yield and tensile strength ratio for the different casting modulus.


2019 ◽  
Vol 25 (3) ◽  
pp. 292-296 ◽  
Author(s):  
Aliaksandr BAHDANOVICH ◽  
Regita BENDIKIENE ◽  
Ramunas CESNAVICIUS ◽  
Antanas CIUPLYS ◽  
Vytautas GRIGAS ◽  
...  

This article presents the results of a set of innovative research to analyse a new structural material – steel like austempered ductile cast iron with mechanical properties similar to heat-treated steel, and with technological and exploitation characteristic close to high-strength cast iron with nodular graphite. Specific examples of its high efficiency for the manufacture of critical, mass and heavy-loaded components of modern machinery and equipment are presented. New structural material MoNiCa was tested on tension and was compared to commercial grades of austempered ductile cast irons and heat treated steels. Unconventional behaviour of examined material was observed: with tensile strength increase to almost 1600 MPa the metal became less brittle. Hardness test revealed another distinctive feature of new material that there is no linear relation between strength and hardness increase, different hardness values ~ 40 HRC or ~ 55 HRC can be achieved with the same tensile strength 1000 – 1200 MPa. Microscopic analysis demonstrated of sophisticated structure formed owing to different regimes of austempering treatment. Specific properties emerged from successful ratio of three elements Mo, Ni, and Cu (carbon equivalent), and properly chosen heat treatment modes. DOI: http://dx.doi.org/10.5755/j01.ms.25.3.23079


2017 ◽  
Vol 83 (851) ◽  
pp. 16-00455-16-00455 ◽  
Author(s):  
Tomohiro IKEDA ◽  
Takuo UMETANI ◽  
Nobuhiro KAI ◽  
Keisaku OGI ◽  
Daichi AKAGI ◽  
...  

2017 ◽  
Vol 47 ◽  
pp. 46-53 ◽  
Author(s):  
Israel Martinez ◽  
Ryutaro Tanaka ◽  
Yasuo Yamane ◽  
Katsuhiko Sekiya ◽  
Keiji Yamada ◽  
...  

2017 ◽  
Vol 62 (2) ◽  
pp. 1113-1117
Author(s):  
Seung-Yeon Park ◽  
J.H. Kim ◽  
S.J. Seo ◽  
J.S. On ◽  
K.M. Lim

AbstractIn this study, we have developed the manufacturing technology for high strength gray cast irons by using the spent permanent magnet scraps. The cast specimen inoculated by using a spent magnet scraps showed the excellent tensile strength up to 306MPa. This tensile strength value is 50MPa higher than that of the specimen cast without inoculation, and is similar to that of the specimen inoculated by using the expensive misch-metal. These superior mechanical properties are attributed to complex sulfides created during solidification that promote the formation and growth of Type-A graphite. It is therefore concluded that spent magnets scrap can provide an efficient and cost-effective inoculation agent for the fabrication of high-performance gray cast iron.


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