scholarly journals A Thermal and Acid Treatment for Carbon Extraction from Cast Iron and Its Application to Ams Dating of Cast Iron Objects from Ancient Korea

Radiocarbon ◽  
2010 ◽  
Vol 52 (3) ◽  
pp. 1312-1321 ◽  
Author(s):  
J S Park ◽  
G S Burr ◽  
A J T Jull
Keyword(s):  
Cast Iron ◽  
Room Temperature ◽  
White Cast Iron ◽  
Controlled Environment ◽  
Thermal Treatments ◽  
Ams Dating ◽  
Iron Artifacts ◽  
Cementite Phase ◽  
The University ◽  
Martensite Matrix

A method of thermal and acid treatments was developed at the Archaeo-metallurgy Laboratory of Hongik University in Korea to extract carbon from cast iron, and carbon objects thus prepared from cast iron artifacts of ancient Korea were dated at the University of Arizona's AMS Facility. The thermal treatments consist of heating a specimen to ∼1000 °C in a controlled environment with reduced oxygen potential, then cooling it rapidly to room temperature. The heating causes the cementite phase in white cast iron to be graphitized and the quenching suppresses pearlite formation. The specimen then consists of flakes of graphite embedded in a matrix of martensite. The next stage of the treatment is to dissolve the martensite matrix in a solution of nitric and hydrochloric acids to release the graphite as a powder. This material is then cleaned, dried, and pressed into target holders for accelerator mass spectrometry (AMS) analysis. The method was applied to a collection of artifacts from the Korean Three Kingdoms period (about AD 300–668) and the AMS results were compared with chronological estimates from other means.

scholarly journals Analysis of the Influence of Hot Impacts on the Transformation of White Cast Iron

2021 ◽  
Vol 45 (1) ◽  
pp. 25-31
Author(s):  
Ekbal Mohammed Saeed Salih ◽  
Ahmed Ouda Al-Roubaiy ◽  
Yasser Louy Azeez Salih
Keyword(s):  
Cast Iron ◽  
Thermal Treatment ◽  
High Temperatures ◽  
White Cast Iron ◽  
Grey Cast Iron ◽  
Common Method ◽  
Thermal Treatments ◽  
Long Period ◽  
Short Period ◽  
Grey Cast

Heat treatments are the most common method of transforming or modifying the structure of white cast iron. Cementite tapes can be decomposed at high temperatures and over a long period of time. These thermal treatments require special furnaces and a long period of time, as well as a high cost with major problems associated with these techniques. In this study, a mechanical thermal treatment was employed, which includes two basic stages, the first being heating at a certain temperature 1100℃ for a rather short period of time, then applying sequential strokes (one stroke or group of strokes) for a period not exceeding a few minutes. The findings proved that heating for short or long periods of time and at 1100℃ is not sufficient to get rid of cementite tapes, as the structure remained white cast iron. The important matter here is that the effect of the hot impact on the transformation of white cast iron into grey is related to the formation ratio. In this regard, the results uncover that using hot impact and at the same temperature, but at higher rates of forming (i.e., greater than 70%) the structure is completely transformed into grey cast iron.

Thermomechanical Treatment of a 4340 Ni-Cr-Mo Alloy Steel

1981 ◽  
Vol 39 ◽  
pp. 314-315 ◽  
Author(s):  
M.T. Jahn ◽  
J.C. Yang ◽  
C.M. Wan
Keyword(s):  
Mechanical Property ◽  
Chemical Composition ◽  
Alloy Steel ◽  
Thermomechanical Treatment ◽  
Room Temperature ◽  
Good Combination ◽  
Thermal Treatments ◽  
Low Carbon ◽  
4340 Steel ◽  
Good Improvement

4340 Ni-Cr-Mo alloy steel is widely used due to its good combination of strength and toughness. The mechanical property of 4340 steel can be improved by various thermal treatments. The influence of thermomechanical treatment (TMT) has been studied in a low carbon Ni-Cr-Mo steel having chemical composition closed to 4340 steel. TMT of 4340 steel is rarely examined up to now. In this study we obtain good improvement on the mechanical property of 4340 steel by TMT. The mechanism is explained in terms of TEM microstructures4340 (0.39C-1.81Ni-0.93Cr-0.26Mo) steel was austenitized at 950°C for 30 minutes. The TMTed specimen (T) was obtained by forging the specimen continuously as the temperature of the specimen was decreasing from 950°C to 600°C followed by oil quenching to room temperature. The thickness reduction ratio by forging is 40%. The conventional specimen (C) was obtained by quenching the specimen directly into room temperature oil after austenitized at 950°C for 30 minutes. All quenched specimens (T and C) were then tempered at 450, 500, 550, 600 or 650°C for four hours respectively.

High-temperature erosive wear characteristics and bonding requirements of hard carbides cast-in insertion multi-component white cast iron

Wear ◽  
2021 ◽  
pp. 203672
Author(s):  
Kenta Kusumoto ◽  
Kazumichi Shimizu ◽  
V.G. Efremenko ◽  
Hiroya Hara ◽  
Masato Shirai ◽  
...  
Keyword(s):  
Cast Iron ◽  
High Temperature ◽  
White Cast Iron ◽  
Erosive Wear ◽  
Wear Characteristics

Effect of Minor Additives on First Stage Graphitisation in White Cast Iron

1984 ◽  
Vol 34 ◽  
Author(s):  
P. L. Roy ◽  
A. K. Chakrabart ◽  
P. Banerjee
Keyword(s):  
Mechanical Properties ◽  
Cast Iron ◽  
Sodium Chloride ◽  
Yield Strength ◽  
White Cast Iron ◽  
Elemental Sulphur ◽  
Optimum Dose ◽  
White Iron ◽  
Kinetics Of ◽  
Strength And Ductility

ABSTRACTMinor additions (0.05-0.2 wt.%) of sodium chloride, hexachloroethane and elemental sulphur to commercial white iron melts have been found to enhance the kinetics of first stage graphitisation during subsequent annealing of white iron samples. The optimum dose of sodium chloride and hexachloroethane addition is around 0.1%. Yield strength and ductility of annealed test bars treated with NaCl or C2Cl6 compare favourably with those of untreated test bars. Sulphur treatment causes slight deterioration in mechanical properties. Fully grown nodules in both treated and untreated samples appear porous under SEM. Possible mechanisms of acceleration of graphitisation in the treated samples have been suggested.

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