Growth of cast iron due to phase transformations and oxidation processes

1970 ◽  
Vol 12 (12) ◽  
pp. 991-993
Author(s):  
G. F. Tikhonov ◽  
A. P. Rukavishnikova
Keyword(s):  
Cast Iron ◽  
Phase Transformations ◽  
Oxidation Processes

Mechanisms of phase transformations during laser treatment of grey cast iron

1992 ◽  
Vol 27 (13) ◽  
pp. 3487-3496 ◽  
Author(s):  
N. Zárubová ◽  
V. Kraus ◽  
J. Čermák
Keyword(s):  
Cast Iron ◽  
Phase Transformations ◽  
Laser Treatment ◽  
Grey Cast Iron ◽  
Grey Cast

Kinetics of the reduction-oxidation processes taking place during the heating of powders produced from cast iron swarf

1988 ◽  
Vol 27 (6) ◽  
pp. 411-414
Author(s):  
S. S. Kiparisov ◽  
O. V. Padalko ◽  
E. S. Bogodukhova ◽  
L. A. Pronin ◽  
A. S. Mints
Keyword(s):  
Cast Iron ◽  
Oxidation Processes ◽  
Kinetics Of

scholarly journals Long-term heat treatment of collector bars for aluminium electrolysis: impact on microstructure and electrical properties

2020 ◽  
Vol 2 (9) ◽  
Author(s):  
Jonas Hankel ◽  
Sandra Kernebeck ◽  
Friederike Deuerler ◽  
Sebastian Weber
Keyword(s):  
Electrical Conductivity ◽  
Energy Efficiency ◽  
Cast Iron ◽  
Electrical Properties ◽  
Phase Transformations ◽  
Diffusion Processes ◽  
Electrolysis Cell ◽  
Service Temperature ◽  
Aluminium Electrolysis ◽  
The Impact

Abstract In order to identify possible optimizations regarding the electrical energy efficiency of an aluminium electrolysis cell, the impact of service temperature on microstructure and electrical properties of the cell cathode was investigated. The investigations include experiments regarding the chemical composition, especially the content of carbon, the electrical conductivity and the microstructure at selected positions. Thermodynamic calculations were used to estimate local service temperatures and explain phase transformations and formations. It was found that due to the increased service temperature diffusion processes of carbon took place to a particular extent between cast iron and collector bar. As a result, the carbon content in the collector bar changed from 0.06 to 1.05–1.4 wt%, while in the cast iron a reduction from 3.47 to < 1.50 wt% took place. These processes led to isothermal phase transformations and formations, that changed the matrix of the collector bar from austenitic with low content of ferrite to an austenitic matrix accompanied by precipitation of secondary, predominantly allotriomorphic cementite at service temperature. It was then shown that this has a negative effect on collector bar and decreases the electrical conductivity by up to 26 %. It was also discovered that graphite spheroidization within the grey cast iron has a positive effect on its electrical conductivity, which has increased by 52 %. The results provide the basis to gain an understanding of the carbon diffusion related processes within the cathode of an electrolysis cell and reveal further potential to increase the energy efficiency of primary aluminium production.

Enhanced densification of white cast iron powders by cyclic phase transformations under stress

1982 ◽  
Vol 13 (3) ◽  
pp. 355-361 ◽  
Author(s):  
Oscar A. Ruano ◽  
Jeffrey Wadsworth ◽  
Oleg D. Sherby
Keyword(s):  
Cast Iron ◽  
Phase Transformations ◽  
White Cast Iron ◽  
Iron Powders ◽  
Cyclic Phase

scholarly journals Peculiarities of Alloying Effect on the Eutectic Cementite Behavior Under Hot Rolling

2019 ◽  
Vol 2 (2) ◽  
pp. 289-300
Author(s):  
Tatiana Mironova ◽  
Svetlana Proidak
Keyword(s):  
Cast Iron ◽  
Phase Transformations ◽  
Hot Rolling ◽  
High Hardness ◽  
Hot Working ◽  
Plastic Working ◽  
Alloying Effect ◽  
Carbide Transformation ◽  
Dynamic Softening ◽  
Chilled Cast Iron

Abstract Currently, cast iron remains one of the major modern casting materials in metallurgy and machine-building industry and is sure to take the lead in the future. Chilled cast iron has high hardness and wear resistance due to a large number of carbide phases in its structure. However, low ductility and impact hardness essentially limit its applicability in terms of processing. Hot plastic working, under which the eutectic net crushing is observed, appears to be one of the most effective means of the eutectic alloy products shape and microstructure transformation. Chilled cast iron properties fundamentally improve after hot plastic working: ductility, strength and impact hardness increase by 2-3 times on retention of the high hardness factor. Chilled cast iron ductility increase can be attained when using phase transformations in eutectic cementite under lean alloying with carbide forming elements. The purpose of the paper is to study alloying effect on the chilled cast iron ductility as well as eutectic cementite behavior under hot rolling. In the paper hardening and softening of the structural components in chilled cast iron under hot working have been studied. The deformation texture forming in eutectic cementite under hot rolling has been revealed, which is connected with the dynamic softening and depends on the degree and the nature of its alloying. The mechanism and regularities of the phase transformation effect in cementite on its behavior under plastic deformation and on the alloys ductility in general have been studied. In cementite chromium alloying initiates processes, that can be characterized as the pre-precipitation stage of the new phases, and this way it contributes to the cast iron ductility reduction and embrittles cementite. Carbide transformation, that occurs in eutectic cementite under alloying with vanadium, stimulates softening of the alloy and increases its ductility level. Moreover, the multiple glide planes {130},{011},{112} in cementite have been determined. It has been found out, that in supersaturated cementite vanadium carbides precipitation stimulates the extra glide plane {111} occurrence under hot rolling. The essence of the carbide transformation phenomenon is that under hot working there occurs the lubricating effect at the transition of the metastable iron carbide condition, which is strengthened with vanadium supersaturation and mechanical hardening, to a more stable condition due to precipitation of the proeutectoid constituents on the one hand, and because of the dynamic softening processes on the other hand. At that, the autocatalyticity effect is observed: there is precipitation of carbides with hardening and softening, similar to the processes that arise as a result of the superplastic effect induced by phase transformations.

Surface of Cast Iron after Laser Hardening

2013 ◽  
Vol 685 ◽  
pp. 92-96 ◽  
Author(s):  
Stanislav Němeček
Keyword(s):  
Cast Iron ◽  
Phase Transformations ◽  
Automotive Industry ◽  
Abrasion Resistance ◽  
Surface Hardening ◽  
Laser Surface ◽  
Coarse Grained ◽  
Body Parts ◽  
High Demand ◽  
Hardness Values

Laser surface hardening of cast iron is not trivial due to the material’s heterogeneity and coarse-grained microstructure, particularly in massive castings. Despite that, hardening of heavy moulds for automotive industry is in high demand. The present paper summarises the findings collected over several years of study of materials structure and surface properties. Phase transformations in the vicinity of graphite are described using examples from production of body parts in automotive industry. The description relates to formation of martensite and carbide-based phases, which leads to hardness values above 65 HRC and to excellent abrasion resistance.

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