In Situ Observation of Mesoscopic Fatigue Deformation Behavior of a Nodular Cast Iron

Time-resolved and in-situ observations using synchrotron radiation X-rays were performed to observe solidification of cast iron (CE=4.5, 0.02mass%Mg). Morphology of graphite particles was influenced by specimen holder material. In the Al2O3 holder, graphite particles were spheroidal at the beginning and then deviated from the spheroidal shape. In addition, the coupled eutectic solidification of austenite and graphite occurred at the final stage. In contrast, the divorced eutectic solidification, in which graphite particles and austenite dendrites independently grew, was selected until the end of solidification in MgO holder. Spheroidal graphite particles were engulfed by austenite. Consequently, typical microstructure observed in ductile cast iron was reproduced in the in-situ observation. The results suggested that oxygen potential, which was determined by Al2O3 or MgO (specimen holder) in the observations, could be an important factor for the selection of eutectic growth mode and graphite morphology.

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TEM in-situ Observation of Indentation-induced Deformation Behavior

Materia Japan ◽

10.2320/materia.48.614 ◽

2009 ◽

Vol 48 (12) ◽

pp. 614-614

Author(s):

Takahito Ohmura ◽

Zhang Ling ◽

Kaoru Sekido ◽

Kaneaki Tsuzaki ◽

Toru Hara

Keyword(s):

Deformation Behavior ◽

In Situ Observation

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In-Situ Observation of Deformation Behavior on Mg Single- and Poly-Crystals by Modified Optical Indentation Microscopy

The Proceedings of the Materials and Mechanics Conference ◽

10.1299/jsmemm.2017.os0704 ◽

2017 ◽

Vol 2017 (0) ◽

pp. OS0704

Author(s):

Takahiro MINETA ◽

Seiji MIURA ◽

Kazuhiko OKA ◽

Tatsuya MIYAJIMA ◽

Hiroyuki SATO

Keyword(s):

Deformation Behavior ◽

In Situ Observation

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High-Temperature Oxidation of a High Silicon SiMo Spheroidal Cast Iron in Air with In Situ Change in H2O Content

Materials Science Forum ◽

10.4028/www.scientific.net/msf.925.353 ◽

2018 ◽

Vol 925 ◽

pp. 353-360 ◽

Cited By ~ 6

Author(s):

André Ebel ◽

Serge Yapi Brou ◽

Benoît Malard ◽

Jacques Lacaze ◽

Daniel Monceau ◽

...

Keyword(s):

Cast Iron ◽

Water Vapor ◽

Oxidation Kinetics ◽

Nodular Cast Iron ◽

Isothermal Oxidation ◽

Effect Of Temperature ◽

Oxide Interface ◽

Humid Air ◽

Temperature Oxidation

Exhaust manifolds for diesel engines are made of high-Si ferritic nodular cast irons. It is experimentally well established that their oxidation kinetics are highly sensitive to the presence of water vapor, though the mechanism for such an effect is still controversial. In the present work, isothermal oxidation tests were performed on a SiMo nodular cast iron at 700°C and 800°C in dry and humid air for 25 and 50 hours. Other samples were oxidized for 50 h with in-situ change in H2O content after 25 h, switching from dry air to humid air or the other way round. Samples were then analyzed using XRD, SEM-EDS and Raman spectroscopy. Thermogravimetric records clearly showed the effect of temperature and environment on oxidation and decarburization. The kinetics of these phenomena depends on silica formation at the metal-oxide interface. At both temperatures, water vapor was seen to promote internal oxidation of Si instead of its external oxidation. This leads to higher oxidation kinetics at 700°C and higher decarburization kinetics at 800°C.

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In-situ observation of ancient co-fusion steelmaking process based on HT-CLSM

Scientific Reports ◽

10.1038/s41598-020-76326-5 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Shangxiao Qiao ◽

Wei Qian

Keyword(s):

Cast Iron ◽

Laser Scanning ◽

Chinese Literature ◽

Carbon Diffusion ◽

Confocal Laser Scanning Microscope ◽

Confocal Laser ◽

Heating Process ◽

In Situ Observation ◽

Steelmaking Process

AbstractObserving and analyzing the microstructure of zone samples had been an essential concept in the study of co-fusion steelmaking. High-temperature confocal laser scanning microscope (HT-CLSM) provided a new method in the in-situ observation and real-time analysis of the co-fusion steelmaking process. In this research, a series of experiments had been designed based on Shen Kuo’s The Dream Pool Essays (a famous ancient Chinese literature) and carried out by HT-CLSM. The results showed that a new interface was formed with the phase transition during the heating process, which had an essential influence on promoting the carbon diffusion rate in co-fusion steelmaking. The cast iron zone occurred in mushy solidification because of decarbonization. There were collision, aggregation, and other behaviors of inclusions in the cast iron zone and they moved towards the boundary, which led to the purity of the matrix and the aggregation of a large number of inclusions at the boundary.

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