Specification for Steel Tie Plates, Low-Carbon and High-Carbon-Hot-Worked

2021 ◽  
Author(s):  
Keyword(s):  
Low Carbon ◽  
High Carbon

Precipitation at the transformation interface of pearlite in steel

1990 ◽  
Vol 48 (4) ◽  
pp. 912-913
Author(s):  
F. A. Khalid ◽  
D. V. Edmonds
Keyword(s):  
Thin Foil ◽  
Carbon Steels ◽  
Model Alloy ◽  
Low Carbon ◽  
High Carbon ◽  
Growth Interface ◽  
Medium Carbon ◽  
Interphase Precipitation ◽  
Solution Treated ◽  
Wide Range

The austenite/pearlite growth interface in a model alloy steel (Fe-1lMn-0.8C-0.5V nominal wt%) is being studied in an attempt to characterise the morphology and mechanism of VC precipitation at the growth interface. In this alloy pearlite nodules can be grown isothermally in austenite that remains stable at room temperature thus facilitating examination of the transformation interfaces. This study presents preliminary results of thin foil TEM of the precipitation of VC at the austenite/ferrite interface, which reaction, termed interphase precipitation, occurs in a number of low- carbon HSLA and microalloyed medium- and high- carbon steels. Some observations of interphase precipitation in microalloyed low- and medium- carbon commercial steels are also reported for comparison as this reaction can be responsible for a significant increase in strength in a wide range of commercial steels.The experimental alloy was made as 50 g argon arc melts using high purity materials and homogenised. Samples were solution treated at 1300 °C for 1 hr and WQ. Specimens were then solutionised at 1300 °C for 15 min. and isothermally transformed at 620 °C for 10-18hrs. and WQ. Specimens of microalloyed commercial steels were studied in either as-rolled or as- forged conditions. Detailed procedures of thin foil preparation for TEM are given elsewhere.

scholarly journals Interfacial Phenomena and Inclusion Formation Behavior at Early Melting Stages of HCFeCr and LCFeCr Alloys in Liquid Iron

2021 ◽  
Author(s):  
Yong Wang ◽  
Andrey Karasev ◽  
Joo Hyun Park ◽  
Wangzhong Mu ◽  
Pär G. Jönsson
Keyword(s):  
Liquid Iron ◽  
Diffusion Zone ◽  
Early Stage ◽  
Interfacial Phenomena ◽  
Solid Alloy ◽  
Low Carbon ◽  
High Carbon ◽  
Free Zone ◽  
Formation Behavior ◽  
Predetermined Time

AbstractChromium is normally added to liquid alloy in the form of different grades of ferrochromium (FeCr) alloys for the requirement of different alloy grades, such as stainless steels, high Cr cast iron, etc.. In this work, inclusions in two commercially produced alloys, i.e., high-carbon ferrochromium (HCFeCr) and low-carbon ferrochromium (LCFeCr) alloys, were investigated. The FeCr alloy/liquid iron interactions at an early stage were investigated by inserting solid alloy piece into contact with the liquid iron for a predetermined time using the liquid-metal-suction method. After quenching these samples, a diffusion zone between the alloys and the liquid Fe was studied based on the microstructural characterizations. It was observed that Cr-O-(Fe) inclusions were formed in the diffusion zone, FeOx inclusions were formed in the bulk Fe, and an “inclusion-free” zone was detected between them. Moreover, it was found that the HCFeCr was slowly dissolved, but LCFeCr alloy was rapidly melted during the experiment. The dissolution and melting behaviors of these two FeCr alloys were compared and the mechanism of the early-stage dissolution process of FeCr alloys in the liquid Fe was proposed.

scholarly journals Carbon Emission Governance Zones at the County Level to Promote Sustainable Development

Land ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 197
Author(s):  
He Zhang ◽  
Jingyi Peng ◽  
Dahlia Yu ◽  
Lie You ◽  
Rui Wang
Keyword(s):  
Sustainable Development ◽  
Carbon Emission ◽  
Total Carbon ◽  
Small Scale ◽  
County Level ◽  
Low Carbon ◽  
High Carbon ◽  
Governance System ◽  
Medium Carbon ◽  
Indicator Evaluation

Low-carbon governance at the county level has been an important issue for sustainable development due to the large contributions to carbon emission. However, the experiences of carbon emission governance at the county level are lacking. This paper discusses 5 carbon emission governance zones for 1753 counties. The zoning is formed according to a differentiated zoning method based on a multi-indicator evaluation to judge if the governance had better focus and had formulated a differentiated carbon emission governance system. According to zoning results, there is 1 high-carbon governance zone, 2 medium-carbon governance zones, and 2 low-carbon zones. The extensive high-carbon governance zone and medium-carbon zones are key governance areas, in which the counties are mainly located in the northern plain areas and southeast coastal areas and have contributed 51.88% of total carbon emissions. This paper proposes differentiated governance standards for each indicator of the 5 zones. The differentiated zoning method mentioned in this paper can be applied to other governance issues of small-scale regions.

scholarly journals A Novel Decarburizing-Nitriding Treatment of Carburized/through-Hardened Bearing Steel towards Enhanced Nitriding Kinetics and Microstructure Refinement

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 112
Author(s):  
Fuyao Yan ◽  
Jiawei Yao ◽  
Baofeng Chen ◽  
Ying Yang ◽  
Yueming Xu ◽  
...  
Keyword(s):  
Surface Engineering ◽  
Plasma Nitriding ◽  
Nitrided Layer ◽  
Metallographic Analysis ◽  
Material Surface ◽  
Low Carbon ◽  
High Carbon ◽  
Softening Effect ◽  
Microstructure Refinement ◽  
Bearing Steels

Decarburization is generally avoided as it is reckoned to be a process detrimental to material surface properties. Based on the idea of duplex surface engineering, i.e., nitriding the case-hardened or through-hardened bearing steels for enhanced surface performance, this work deliberately applied decarburization prior to plasma nitriding to cancel the softening effect of decarburizing with nitriding and at the same time to significantly promote the nitriding kinetics. To manifest the applicability of this innovative duplex process, low-carbon M50NiL and high-carbon M50 bearing steels were adopted in this work. The influence of decarburization on microstructures and growth kinetics of the nitrided layer over the decarburized layer is investigated. The metallographic analysis of the nitrided layer thickness indicates that high carbon content can hinder the growth of the nitrided layer, but if a short decarburization is applied prior to nitriding, the thickness of the nitrided layer can be significantly promoted. The analysis of nitriding kinetics shows that decarburization reduces the activation energy for nitrogen diffusion and enhances nitrogen diffusivity. Moreover, the effect of decarburization in air can promote surface microstructure refinement via spinodal decomposition during plasma nitriding.

scholarly journals Laser Welding Dissimilar High-Strength Steel Alloys with Complex Geometries

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 792 ◽  
Author(s):  
Panos Efthymiadis ◽  
Khalid Nor
Keyword(s):  
Carbon Steel ◽  
Laser Welding ◽  
Cross Sections ◽  
High Carbon Steel ◽  
High Strength Steels ◽  
High Strength ◽  
Low Carbon ◽  
High Carbon ◽  
Material Chemistry ◽  
Metallurgical Defects

Laser welding of dissimilar high-strength steels was performed in this study for two different geometries, flat and circular samples with material thicknesses of 5 and 8 mm. The material combinations were a low carbon to a medium or high carbon steel. Three different welding systems were employed: a Nd:YAG, a CO2 and a fiber laser. The process stability was evaluated for all the experiments. The resulting full penetration welds were inspected for their surface quality at the top and bottom of the specimens. Cross sections were taken to investigate the resulting microstructures and the metallurgical defects of the welds, such as cracks and pores. Significant hardening occurred in the weld region and the highest hardness values occurred in the Heat Affected Zone (HAZ) of the high carbon steel. The occurrence of weld defects depends strongly on the component geometry. The resulting microstructures within the weld were also predicted using neural network-simulated Continuous Cooling Transformation (CCT) diagrams and predicted the occurrence of a mixture of microstructures, such as bainite, martensite and pearlite, depending on the material chemistry. The thermal fields were measured with thermocouples and revealed the strong influence of component geometry on the cooling rate which in term defines the microstructures forming in the weld and the occurring hardness.

Low Carbon Mobility, Urgent futures and radical transitions

2016 ◽  
Author(s):  
James Higham ◽  
Debbie Hopkins
Keyword(s):  
Rapid Development ◽  
Transportation Systems ◽  
Transport Systems ◽  
Political Agenda ◽  
Low Carbon ◽  
Mobility Patterns ◽  
High Carbon ◽  
Transportation Emissions ◽  
Paris Climate Agreement ◽  
Transport Emissions

More people than ever before are moving more frequently and at accelerating speeds, often for shorter periods of time. These mobilities are largely dependent on unsustainable high-carbon technologies. The continued and accelerating growth of transportation emissions is attributed to changing mobility patterns among the high emitters of hypermobile developed societies, combined with the rapid development of high carbon intensity transport systems in emerging economies. Mitigation of transport emissions remains largely absent from the political agenda, despite growing recognition of the urgent need to address transportation emissions, because it is fundamentally incompatible with neoliberal ideals. The level of decarbonisation required to align regional and global transportation systems with the agreed targets of the Paris Climate Agreement (2015) has proved to be a particularly acute challenge. The Agreement recognises that radical and system-wide transitions toward low carbon mobility are urgently required. It is critically important that the varied social, cultural and geographic contexts of low carbon mobility transitions that are identified in Low Carbon Mobility Transitions are taken up and acted upon to inform the low carbon mobility transformations that are so obviously and urgently required. These insights must inform efforts to ensure the full accountability of transportation emissions, and to ensure that the INDCs that are outlined in the Paris Climate Agreement (2015) are upheld and achieved in full measure.

scholarly journals Microstructure and Properties of Heat Affected Zone in High-Carbon Steel after Welding with Fast Cooling in Water

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5059
Author(s):  
Michail Nikolaevich Brykov ◽  
Ivan Petryshynets ◽  
Miroslav Džupon ◽  
Yuriy Anatolievich Kalinin ◽  
Vasily Georgievich Efremenko ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Heat Affected Zone ◽  
Welded Joints ◽  
High Carbon Steel ◽  
Low Carbon Steel ◽  
Tensile Tests ◽  
Low Carbon ◽  
High Carbon ◽  
Mechanical Wear ◽  
Fast Cooling

The purpose of the research was to obtain an arc welded joint of a preliminary quenched high-carbon wear resistant steel without losing the structure that is previously obtained by heat treatment. 120Mn3Si2 steel was chosen for experiments due to its good resistance to mechanical wear. The fast cooling of welding joints in water was carried out right after welding. The major conclusion is that the soft austenitic layer appears in the vicinity of the fusion line as a result of the fast cooling of the welding joint. The microstructure of the heat affected zone of quenched 120Mn3Si2 steel after welding with rapid cooling in water consists of several subzones. The first one is a purely austenitic subzone, followed by austenite + martensite microstructure, and finally, an almost fully martensitic subzone. The rest of the heat affected zone is tempered material that is heated during welding below A1 critical temperature. ISO 4136 tensile tests were carried out for the welded joints of 120Mn3Si2 steel and 09Mn2Si low carbon steel (ASTM A516, DIN13Mn6 equivalent) after welding with fast cooling in water. The tests showed that welded joints are stronger than the quenched 120Mn3Si2 steel itself. The results of work can be used in industries where the severe mechanical wear of machine parts is a challenge.

scholarly journals Revisiting the Psychology of Denial Concerning Low-Carbon Behaviors: From Moral Disengagement to Generating Social Change

2020 ◽  
Vol 12 (3) ◽  
pp. 935 ◽  
Author(s):  
Susanne Stoll-Kleemann ◽  
Tim O’Riordan
Keyword(s):  
Role Models ◽  
Moral Disengagement ◽  
Dominant Role ◽  
Low Carbon ◽  
High Carbon ◽  
New Findings ◽  
Climate Action ◽  
Climate Crisis ◽  
Behavioral Transformations

This paper reassesses the scope for shifting high-carbon personal behaviors in the light of prevailing insufficient political and regulatory action. Our previous research has shown that citizens regard such behavioral shifts as extremely daunting and create a number of psychological denial mechanisms that draw attention to the inaction of others, including governments. Further theoretical insights and relevant new findings have been attained from a more recent survey of more than 1000 German residents. This reveals that direct denial of anthropogenic climate change is replaced by a denial of responsibility for individual climate action. Ways of moral disengagement play a more dominant role, such as the diffusion and displacement of responsibility, although a majority is aware of—and very much concerned about—the climate crisis. More attention needs to be given for further reinterpretation of the role of moral disengagement to single out adequate strategies for different individuals and groups of people, such as making role models more visible to encourage social learning that could accelerate further necessary moral and behavioral transformations.

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