The tensile fracture behaviour of intercritically annealed and quenched+tempered ferritic ductile iron with dual matrix structure

Kocatepe, Kadir; Cerah, M.; Erdoğan, Mehmet

doi:10.1016/j.matdes.2005.04.012

Cited by 29 publications

(13 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…[1][2][3][4][5][6][7][8][9][10][11] In the newly developed ADI with a dual matrix structure (DMS), the matrix structure consists of proeutectoid ferrite and ausferrite (bainitic ferrite and stabilised high carbon austenite) or martensite. [12][13][14][15][16][17][18][19][20][21][22] This microstructure is obtained by austempering or quenching from a temperature at which both ferrite and austenite are present, rapidly enough for a significant fraction of the austenite to transform to ausferrite or martensite. In the present work, ADI with DMS was obtained by austempering from the intercritical austenitising temperature range which corresponds to the (azczgraphite) region, indicated to the (azc) temperature range in this article.…”

Section: Introductionmentioning

confidence: 99%

“…The ductility is lower than ferritic grades but remains adequate for most applications. [20][21][22] In the literature, very little information is currently available on the mechanical properties of ADI with DMS. 12,14,16 More specifically, no attempts appear to have been made to optimise the mechanical properties by controlling the proeutectoid ferrite and the ausferrite volume fractions and their distribution.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effect of ausferrite volume fraction and morphology on tensile properties of partially austenitised and austempered ductile irons with dual matrix structures

Kılıçlı¹,

Erdoğan²

2007

International Journal of Cast Metals Research

View full text Add to dashboard Cite

In the present study, an unalloyed ductile iron containing 3?50%C, 2?63%Si, 0?318%Mn and 0?047%Mg was intercritically austenitised (partially austenitised) in the two phase region (azc) at temperatures of 795 and 815uC for 20 min, and then was quenched into a salt bath held at an austempering temperature of 365uC for various times to obtain various ausferrite volume fractions. Fine and coarse dual matrix structures were obtained from the two different starting conditions. Some specimens were also conventionally austempered from 900uC for comparison. Results showed that a structure having proeutectoid ferrite plus ausferrite (bainitic ferritezhigh carbon retained or stabilised austenite) was developed. The phase previously described as new ferrite (also called epitaxial ferrite) was observed to form following heat treatment only in specimens with coarse austenite dispersion after austempering from the (azc) temperature range. It was observed that the parent austenite dispersion present at the intercritical austenitising temperature has an effect on the volume fraction of high carbon austenite following austempering. Finer austenite dispersions produced more stabilised high carbon austenite than coarse ones for a given austempering time. The volume fractions of proeutectoid ferrite, new ferrite, ausferrite can be controlled to influence the strength and ductility. Specimens austempered from the (azc) temperature range exhibited much greater ductility than conventionally austempered samples. Within each of the series austempered from the (azc) temperature range, the tensile strength increased and ductility decreased with increasing ausferrite volume fraction and decreasing proeutectoid ferrite volume fraction. However, specimens having a fine ausferritic structure without new ferrite exhibited lower ductility and higher strength than specimens with a coarse ausferritic structure under the same austempering conditions. The specimen with ,60% AFVF (coarse structure) and ,65% AFVF (fine structure) exhibited the best combination of high strength and ductility compared to pearlitic grades, but their ductility was slightly lower than ferritic grades. These materials satisfy the requirements for the strength of quenched and tempered grades and their ductility superior to that of this grade.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effect of ausferrite volume fraction and morphology on tensile properties of partially austenitised and austempered ductile irons with dual matrix structures

Kılıçlı¹,

Erdoğan²

2007

International Journal of Cast Metals Research

View full text Add to dashboard Cite

show abstract

“…This sharp difference in fracture pattern over such a lowageing temperature for a short period of time cannot be explained by the effect of strain ageing and support arguments that introducing different percentage martensite into ferrite matrix affects the fracture behaviour. Kocatepe et al [39] indicated in their work that with increasing martensite volume fractions, the fracture pattern changed from ductile to brittle.…”

Section: Mechanical Propertiesmentioning

confidence: 99%

Static strain ageing behaviour of dual phase steels

Gündüz

2008

Materials Science and Engineering: A

View full text Add to dashboard Cite

“…They showed that the austenite volume fraction and its carbon content during intercritical austenitizing can be controlled. They also showed that the proof and tensile stresses of ductile irons with dual-matrix structure are much greater than those of pearlitic and ferritic grades and that its ductility is lower than that of ferritic grades although it remains adequate for most applications [5,10,11].…”

Section: Introductionmentioning

confidence: 99%

Investigation of the Variations in Microstructure and Mechanical Properties of Dual-Matrix Ductile Iron by Magnetic Barkhausen Noise Analysis

Gür

Özer

Erdoğan

2008

Research in Nondestructive Evaluation

Self Cite

View full text Add to dashboard Cite

The variations in the microstructure and tensile properties of dual-matrix ductile irons have been investigated non-destructively by Magnetic Barkhausen Noise (MBN) method. Specimens have been intercritically austenitised at 795 C and 815 C for 20 minutes, and then oil-quenched to obtain different martensite volume fractions. Two specimens, namely as-cast and oil-quenched from 900 C, were prepared for comparison purpose. To investigate the effect of tempering, some specimens were tempered at 500 C for 1 h and 3 h. The results showed that there is a good correlation between MBN response and variations in microstructure and mechanical properties. The volume fraction of martensite can be controlled to modify the mechanical properties, and all changes in the microstructure can be nondestructively monitored by MBN.

show abstract

The tensile fracture behaviour of intercritically annealed and quenched+tempered ferritic ductile iron with dual matrix structure

Cited by 29 publications

References 9 publications

Effect of ausferrite volume fraction and morphology on tensile properties of partially austenitised and austempered ductile irons with dual matrix structures

Effect of ausferrite volume fraction and morphology on tensile properties of partially austenitised and austempered ductile irons with dual matrix structures

Static strain ageing behaviour of dual phase steels

Investigation of the Variations in Microstructure and Mechanical Properties of Dual-Matrix Ductile Iron by Magnetic Barkhausen Noise Analysis

Contact Info

Product

Resources

About