Effect of Microstructure on Fatigue Strength of Intercritically Austenitized and Austempered Ductile Irons with Dual Matrix Structures

Ovalı, İsmail; Kılıçlı, Volkan; Erdoğan, Mehmet

doi:10.2355/isijinternational.53.375

Cited by 22 publications

(10 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Thus, a combination of high strength and high ductility is not possible to produce in conventionally processed ADI. Therefore, in recent years many researchers [11][12][13][14][15][16][17][18] have used an intercritical austempering process to improve the ductility of ADI.…”

Section: Hcmentioning

confidence: 99%

A Novel Step-Up Austenitization and Austempering Heat Treatment Process for Ductile Cast Iron

Joshi¹,

Putatunda

Boileau

2020

RDMS

View full text Add to dashboard Cite

A novel heat treatment process has been conceived for creation of Austempered Ductile Iron (ADI) with combination of high strength and high ductility. The process involves a step up austenitization of ductile cast iron after initial austenitization in the lower intercritical temperature range, then raising the temperature to the fully austenitic region followed by austempering at low bainitic temperatures.In this investigation an unalloyed ductile cast iron with low Carbon Equivalent (CE) was processed by the conceived novel austempering process. The microstructure and the mechanical properties of the material processed by this technique were characterized by optical metallography, Scanning Electron Microscopy (SEM) and X-ray diffraction. The influence of austempering temperature and time on the microstructure and mechanical properties of this material was also examined.The test results show that resulting microstructure of the material processed by this novel technique consists of very fine scale bainitic ferrite, proeutectoid ferrite and high carbon austenite. ADI with high yield strength and good ductility were obtained as a result of this novel heat treatment process. The mechanical properties were comparable to the conventionally processed ADI (austenitized at fully austenitic temperature range and subsequently austempered at the same austempering temperature and time). However, the ductility was significantly higher than the conventionally processed ADI.

show abstract

Section: Hcmentioning

confidence: 99%

A Novel Step-Up Austenitization and Austempering Heat Treatment Process for Ductile Cast Iron

Joshi¹,

Putatunda

Boileau

2020

RDMS

View full text Add to dashboard Cite

show abstract

“…Bu sonuç literatürle paralellik göstermektedir [2, 10,[27][28][29][30][31][32][33][34]. Östemperleme ile yorulma sınırındaki bu artış, ince ösferritik yapının perlitik yapıya göre yorulma çatlaklarının ilerlemesine karşı direncini artırdığına dayandırılmaktadır [10,[27][28][29][30][31][32][33][34][35][36].…”

Section: Yorulma öZellikleri (Fatigue Properties)unclassified

Östemperlenmiş Küresel Grafitli Dökme Demirlerde İndüksiyonla Yüzey Sertleştirmenin Yorulma Sınırı Üzerine Etkisi

Oktay

Kılıçlı

Erdoğan

2018

Gazi Üniversitesi Fen Bilimleri Dergisi Part C: Tasarım Ve Teknoloji

View full text Add to dashboard Cite

Bu çalışmada, östemperlenmiş küresel grafitli dökme demirlerde indüksiyonla yüzey sertleştirmenin yorulma sınırı üzerine etkisi araştırılmıştır. Bu amaçla, GGG70 sınıfı küresel grafitli dökme demir numuneler; 900°C'de 90 dk östenitlenmiş ve ardından 375°C sıcaklıktaki tuz banyosunda 120 dk östemperlenmiştir. Daha sonra dökülmüş ve östemperlenmiş koşullardaki yorulma numunelerine yüksek frekanslı indüksiyonla yüzey sertleştirme uygulanmıştır. Dökülmüş halde, östemperlenmiş, dökülmüş halde + indüksiyonla sertleştirilmiş ve östemperlenmiş+indüksiyon ile sertleştirilmiş numunelerin yorulma sınırları, dönel eğmeli yorulma testi cihazı belirlenmiştir. Deneysel sonuçlar, test edilen numuneler arasında en iyi yorulma sınırı sonuçlarını östemperlenmiş+yüzeyi indüksiyonla sertleştirilmiş numunelerin sergilediğini göstermiştir.

show abstract

“…Ductile cast iron (DCI) 1,2) has attracted attention as a material that can replace welded joints. 3) In our previous experimental study, the authors revealed that the fatigue strength of DCI joints is about 2 times or more larger than that of non-load-carrying cruciform welded joints.…”

Section: Introductionmentioning

confidence: 99%

Lowest Fatigue Limit Estimation of Ductile Cast Iron Joints by Considering Maximum Defect Size Toward Replacing Welded Joints

Hidaka¹,

Noda²,

Sano³

et al. 2020

ISIJ Int.

View full text Add to dashboard Cite

In our earlier study, the authors revealed that the fatigue limit of ductile cast iron (DCI) specimens whose shapes are similar to the welded joint shapes is about three times larger than that of the welded joint specimens. However, since many defects are usually included in the DCI specimens, the fatigue limit of DCI joints decreases with increasing the maximum defect size. In this paper, therefore, the maximum defect size is estimated by using statistics of extremes. Then, the lowest fatigue limit corresponding to the maximum defect size is estimated from the 4 parameter model and compared with the lowest fatigue limit of the welded joint. As a result, it was confirmed that the lowest fatigue limit of the DCI specimens is about twice as large as the welded joint.KEY WORDS: fatigue strength; ductile cast iron; welded joint; statistics of extremes; 4 parameter model;area parameter model.

show abstract

Effect of Microstructure on Fatigue Strength of Intercritically Austenitized and Austempered Ductile Irons with Dual Matrix Structures

Cited by 22 publications

References 36 publications

A Novel Step-Up Austenitization and Austempering Heat Treatment Process for Ductile Cast Iron

A Novel Step-Up Austenitization and Austempering Heat Treatment Process for Ductile Cast Iron

Östemperlenmiş Küresel Grafitli Dökme Demirlerde İndüksiyonla Yüzey Sertleştirmenin Yorulma Sınırı Üzerine Etkisi

Lowest Fatigue Limit Estimation of Ductile Cast Iron Joints by Considering Maximum Defect Size Toward Replacing Welded Joints

Contact Info

Product

Resources

About