scholarly journals The Role of Carbon in the Mechanism of Ferritic-Austenitic Cast Steel Solidification

2014 ◽  
Vol 14 (3) ◽  
pp. 83-86
Author(s):  
G. Stradomski
Keyword(s):  
Carbon Content ◽  
Cast Steel ◽  
Hot Cracking ◽  
Cast Steels ◽  
Microstructure Morphology

Abstract The paper presents the results of research on the microstructure of GX2CrNiMoCuN25-6-3-3 and GX2CrNiMoCuN25-6-3 cast steels with a varying carbon content. The cause for undertaking the research were technological problems with hot cracking in bulk castings of duplex cast steel with a carbon content of approx. 0.06% and with 23% Cr, 8.5% Ni, 3% Mo and 2.4% Cu. The research has shown a significant effect of increased carbon content on the ferrite and austenite microstructure morphology, while exceeding the carbon content of 0.06% results in a change of the shape of primary grains from equiaxial to columnar.

scholarly journals The Role of Chemical Composition of High-Manganese Cast Steels on Wear of Excavating Chain in Railway Shoulder Bed Ballast Cleaning Machine

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7794
Author(s):  
Janusz Krawczyk ◽  
Michał Bembenek ◽  
Jan Pawlik
Keyword(s):  
Chemical Composition ◽  
Cross Sections ◽  
Structural Integrity ◽  
Cast Steel ◽  
Maximum Speed ◽  
Chemical Compositions ◽  
Main Task ◽  
High Manganese ◽  
Cast Steels

The main task for a ballast bed is to transmit the sleeper pressure in a form of stress cone to the subsoil, provide proper drainage and resist the sleeper displacement. Poorly maintained ballast could severely limit the maximum speed capacity and create further problems with the structural integrity, possibly leading to a complete failure of a given rail line. To prevent the unwanted corollaries, the ballast bed has to be periodically cleaned with an appropriate machinery. In this paper the authors investigated the effect of the chemical composition on the physical properties of the ballast excavating chains made of high-manganese steels. The authors focused on the wear mechanism, work hardening ability and hardness in the cross-sections areas. A microstructure analysis was performed as well, and observations revealed divergent morphology of precipitations at the grain boundaries, which influenced the size of austenite grains. The deformation twins formed as a result of operation were noticed in the samples. Research has shown that less carbon and chromium reduces the hardness of cast steel, and it specifically affects the ability to strain hardening. The authors explained the role of adjustments in chemical composition in the operational properties of high-manganese cast steels. It has been shown in the paper that different chemical compositions affect the properties of the alloys, and this causes different types of wear. The high content of chromium increases the hardness of materials before and after plastic deformation hardening, which in the conditions of selector chains results in greater dimensional stability during wear of holes in pin joints and will be more susceptible to abrasive wear in the presence of dusts from the ballast than creep.

scholarly journals Fracture Mechanisms in Steel Castings

2013 ◽  
Vol 13 (3) ◽  
pp. 88-91 ◽  
Author(s):  
Z. Stradomski ◽  
S. Stachura ◽  
G. Stradomski
Keyword(s):  
Cast Steel ◽  
Hot Cracking ◽  
Hadfield Steel ◽  
Fracture Mechanisms ◽  
Structural Factors ◽  
Low Carbon ◽  
High Carbon ◽  
Cast Steels ◽  
Steel Castings ◽  
Low Alloyed Steel

Abstract The investigations were inspired with the problem of cracking of steel castings during the production process. A single mechanism of decohesion - the intergranular one - occurs in the case of hot cracking, while a variety of structural factors is decisive for hot cracking initiation, depending on chemical composition of the cast steel. The low-carbon and low-alloyed steel castings crack due to the presence of the type II sulphides, the cause of cracking of the high-carbon tool cast steels is the net of secondary cementite and/or ledeburite precipitated along the boundaries of solidified grains. Also the brittle phosphor and carbide eutectics precipitated in the final stage solidification are responsible for cracking of castings made of Hadfield steel. The examination of mechanical properties at 1050°C revealed low or very low strength of high-carbon cast steels.

scholarly journals The Structure of the Silumin Coat on Alloy Cast Steels

2012 ◽  
Vol 12 (2) ◽  
pp. 215-220
Author(s):  
T. Szymczak
Keyword(s):  
Phase Structure ◽  
High Speed ◽  
Cast Steel ◽  
Intermetallic Phases ◽  
External Layer ◽  
Cast Steels ◽  
Steel Grades ◽  
The Absolute ◽  
The Given ◽  
Alloy Cast

The Structure of the Silumin Coat on Alloy Cast Steels The work presents the analysis results of the structure of the coat obtained by dipping in silumin AlSi5 of two grades of alloy cast steel: GX6CrNiTi18-10 (LH18N9T) and GX39Cr13 (LH14). The temperature of the silumin bath was 750±5°C, and the hold-up time of the cast steel element τ = 180 s. The absolute thickness of the coat obtained in the given conditions was g = 104 μm on cast steel GX6CrNiTi18-10 and g = 132 μm on GX39Cr13. The obtained coat consisted of three layers of different phase structure. The first layer from the base "g1" was constructed of the phase AlFe including Si and alloy additives of the tested cast steel grades: Cr and Ni (GX6CrNiTi18-10) and Cr (GX39Cr13). The second layer "g1" of intermetallic phases AlFe which also contains Si and Cr crystallizes on it. The last, external layer "g2" of the coat consists of the silumin containing the intermetallic phases AlFeSi which additionally can contain alloy additives of the cast steel. It was shown that there were no carbides on the coat of the tested cast steels which are the component of their microstructure, as it took place in the case of the coat on the high speed steels.

scholarly journals The Cracking Mechanism of Ferritic-Austenitic Cast Steel

2016 ◽  
Vol 16 (4) ◽  
pp. 153-156 ◽  
Author(s):  
G. Stradomski
Keyword(s):  
Chemical Composition ◽  
Cast Steel ◽  
Hot Cracking ◽  
Hadfield Steel ◽  
Structural Factors ◽  
Low Carbon ◽  
Secondary Phases ◽  
High Tendency ◽  
Iron Manganese ◽  
Low Solubility

Abstract In the high-alloy, ferritic - austenitic (duplex) stainless steels high tendency to cracking, mainly hot-is induced by micro segregation processes and change of crystallization mechanism in its final stage. The article is a continuation of the problems presented in earlier papers [1 - 4]. In the range of high temperature cracking appear one mechanism a decohesion - intergranular however, depending on the chemical composition of the steel, various structural factors decide of the occurrence of hot cracking. The low-carbon and low-alloy cast steel casting hot cracking cause are type II sulphide, in high carbon tool cast steel secondary cementite mesh and / or ledeburite segregated at the grain solidified grains boundaries, in the case of Hadfield steel phosphorus - carbide eutectic, which carrier is iron-manganese and low solubility of phosphorus in high manganese matrix. In duplex cast steel the additional factor increasing the risk of cracking it is very “rich” chemical composition and related with it processes of precipitation of many secondary phases.

HUMUS FRACTION RATIOS AS A MEANS OF DISCRIMINATING BETWEEN HORIZON TYPES

1980 ◽  
Vol 60 (2) ◽  
pp. 219-229 ◽  
Author(s):  
L. E. LOWE
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Carbon Content ◽  
Fulvic Acid ◽  
Soil Classification ◽  
Acid Fraction ◽  
Humus Fraction ◽  
Wide Range ◽  
Fraction Distribution

Humus fraction distribution in a wide range of horizon samples was examined by measuring carbon content in humic acid (Ch), in fulvic acid (Cf) and in the strongly colored polyphenolic component of the fulvic acid fraction (Ca). Fraction distribution was described by the ratios Ch/Cf and Ca/Cf. It was concluded that humus fraction ratios were related to horizon types as used in the Canadian System of Soil Classification, and were effective in discriminating between certain horizon types, particularly between Luvisolic Bt and Podzolic Bf. The results also suggested that humus fraction ratios may be effective in separating distinct sub-populations within Ah horizons and Bf horizons in general, based on qualitative differences in organic matter present. Aspects of the role of humus fractions in soil genesis are discussed.

The role of pulverized coal drying temperature in fly ash carbon content and slagging of a tangentially coal-fired boiler

Fuel ◽  
2019 ◽  
Vol 257 ◽  
pp. 115951 ◽  
Author(s):  
Xin Liao ◽  
Qi Zhang ◽  
Wenhu Yang ◽  
Zhongzhu Qiu ◽  
Ruitang Guo ◽  
...  
Keyword(s):  
Fly Ash ◽  
Carbon Content ◽  
Pulverized Coal ◽  
Drying Temperature ◽  
Coal Drying

scholarly journals Effect of Carbon Content on Abrasive Impact Wear Behavior of Cr-Si-Mn Low Alloy Wear Resistant Cast Steels

2019 ◽  
Vol 6 ◽  
Author(s):  
Xiaodong Wang ◽  
Yunbo Chen ◽  
Shizhong Wei ◽  
Lingli Zuo ◽  
Feng Mao
Keyword(s):  
Carbon Content ◽  
Wear Behavior ◽  
Impact Wear ◽  
Wear Resistant ◽  
Cast Steels

Extraction of compounds associated with water repellency in sandy soils of different origin

Soil Research ◽  
2005 ◽  
Vol 43 (3) ◽  
pp. 225 ◽  
Author(s):  
S. H. Doerr ◽  
C. T. Llewellyn ◽  
P. Douglas ◽  
C. P. Morley ◽  
K. A. Mainwaring ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Carbon Content ◽  
Sandy Soils ◽  
Water Repellency ◽  
Organic Carbon Content ◽  
Soil Water Repellency ◽  
Diverse Range ◽  
Additional Information ◽  
The Uk

After an initial evaluation of several solvents, the efficiency of Soxhlet extractions with isopropanol/ammonia (s.g. 0.88) (70 : 30 v : v; 24 h) in extracting compounds associated with water repellency in sandy soils was examined using a range of repellent and wettable control soils (n = 15 and 4) from Australia, Greece, Portugal, The Netherlands, and the UK. Extraction efficiency and the role of the extracts in causing soil water repellency was examined by determining extract mass, sample organic carbon content and water repellency (after drying at 20°C and 105°C) pre- and post-extraction, and amounts of aliphatic C–H removed using DRIFT, and by assessing the ability of extracts to cause repellency in acid-washed sand (AWS). Key findings are: (i) none of organic carbon content, amount of aliphatic C–H, or amount of material extracted give any significant correlation with repellency for this diverse range of soils; (ii) sample drying at 105°C is not necessarily useful before extraction, but may provide additional information on extraction effectiveness when used after extraction; (iii) the extraction removed repellency completely from 13 of the 15 repellent samples; (iv) extracts from all repellent and wettable control soils were capable of inducing repellency in AWS. The findings suggest that compounds responsible for repellency represent only a fraction of the extract composition and that their presence does not necessarily always cause repellency.

scholarly journals Corrosion Behaviour of Low-Alloyed Cast Steel in Diverse State

2015 ◽  
Vol 15 (1) ◽  
pp. 25-28
Author(s):  
M. Kondracki ◽  
A. Studnicki ◽  
J. Szajnar
Keyword(s):  
Heat Treatment ◽  
Corrosion Test ◽  
High Salinity ◽  
Corrosion Behaviour ◽  
Cast Steel ◽  
Mining Industry ◽  
Cast State ◽  
Alloyed Cast ◽  
Cast Steels ◽  
Parts Manufacturing

Abstract In the paper the results and analysis of corrosion tests were presented for low-alloyed cast steel in as-cast state and after heat treatment operations. Such alloys are applied for heavy loaded parts manufacturing, especially for mining industry. The corrosion test were performed in conditions of high salinity, similar to those occurring during the coal mining. The results have shown, that small changes in chemical composition and the heat treatment influence significantly the corrosion behaviour of studied low-alloyed cast steels.

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