scholarly journals Numerical Simulation of the Melting Behavior of Steel Scrap in Hot Metal

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 678
Author(s):  
Nanyang Deng ◽  
Xiaobin Zhou ◽  
Moer Zhou ◽  
Shiheng Peng
Keyword(s):  
Carbon Concentration ◽  
Vertical Direction ◽  
Bath Temperature ◽  
Melting Behavior ◽  
Melting Rate ◽  
Middle Part ◽  
Steel Scrap ◽  
Low Carbon ◽  
Carbon Distribution ◽  
Hot Metal

The current study focuses on the melting behavior of a scrap bar with low carbon content in hot metal which contains high carbon concentration by applying experiments and mathematical modelings. The experiments suggest that higher temperature is favorable for the melting of the bar and the melting rate of the bar is initially high while decreased to a relative stable level after 90 s in the current conditions. It can be found from the mathematical results that the bar temperature is increased near to bath temperature in about 20 s after it was immersed into the bath, and the temperature in the axis of the bar is not distributed evenly during the temperature increase stage. Moreover, the mathematical results shows that a bath circulation flow would be formed in the bath under the effects of temperature and carbon distribution during the melting process. The bath flow near the melting interface would influence the carbon concentration of the molten phase, in turn, affects the melting rate of the bar in the vertical direction. Both the experimental and mathematical results show that the melting rate in the upper part, which is in the upstream of the bath flow, is higher than that of the middle part, followed by the down part of the bar in the downstream of the flow, in which the carbon concentration is much lower than that of the bath. At this period, the main factor that dominate the bar melting is not the temperature but the carbon distribution at the melting interface after the bar temperature is increased to the bath temperature.

scholarly journals Diffusive steel scrap melting in carbon-saturated hot metal—phenomenological investigation at the solid–liquid interface

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1358 ◽  
Author(s):  
Penz ◽  
Schenk ◽  
Ammer ◽  
Klösch ◽  
Pastucha ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Carbon Concentration ◽  
Steel Production ◽  
Production Optimization ◽  
Steel Scrap ◽  
Process Conditions ◽  
Hot Metal ◽  
Scrap Melting ◽  
Solid Liquid Interface ◽  
Solid Liquid

The oxygen steelmaking process in a Linz-Donawitz (LD) converter is responsible for more than 70% of annual crude steel production. Optimization of the process control and numerical simulation of the LD converter are some of the current challenges in ferrous metallurgical research. Because of the process conditions and oxidation of impurities of the hot metal, a lot of chemical heat is generated. Therefore, steel scrap is charged as a coolant with the economical side aspect of its recycling. One of the more complex aspects is, among others, the dissolution and melting behaviour of the scrap in carbon-saturated hot metal. Heat and mass transfer act simultaneously, which has already been investigated by several researchers using different experimental approaches. The appearances at the interface between solid steel and liquid hot metal during diffusive scrap melting have been described theoretically but never investigated in detail. After an experimental investigation under natural and forced convective conditions, the samples were further investigated with optical microscopy and electron probe microanalysis (EPMA). A steep carbon concentration gradient in the liquid appeared, which started at an interface carbon concentration equal to the concentration on the solid side of the interface. Moreover, the boundary layer thickness moved towards zero, which symbolized that the boundary layer theory based on thermodynamic equilibrium was not valid. This fact was concluded through the prevailing dynamic conditions formed by natural and forced convection.

scholarly journals Experimental Investigation of Freezing and Melting Characteristics of Graphene-Based Phase Change Nanocomposite for Cold Thermal Energy Storage Applications

2019 ◽  
Vol 9 (6) ◽  
pp. 1099 ◽  
Author(s):  
Shaji Sidney ◽  
Mohan Dhasan ◽  
Selvam C. ◽  
Sivasankaran Harish
Keyword(s):  
Thermal Conductivity ◽  
Bath Temperature ◽  
Melting Behavior ◽  
Melting Rate ◽  
Graphene Nanoplatelets ◽  
Melting Time ◽  
Functionalized Graphene ◽  
Maximum Increase ◽  
Volume Percentage ◽  
Melting Characteristics

In the present work, the freezing and melting characteristics of water seeded with chemically functionalized graphene nanoplatelets in a vertical cylindrical capsule were experimentally studied. The volume percentage of functionalized graphene nanoplatelets varied from 0.1% to 0.5% with an interval of 0.1%. The stability of the synthesized samples was measured using zeta potential analyzer. The thermal conductivity of the nanocomposite samples was experimentally measured using the transient hot wire method. A ~24% (maximum) increase in the thermal conductivity was observed for the 0.5% volume percentage in the liquid state, while a ~53% enhancement was observed in the solid state. The freezing and melting behavior of water dispersed with graphene nanoplatelets was assessed using a cylindrical stainless steel capsule in a constant temperature bath. The bath temperatures considered for studying the freezing characteristics were −6 °C and −10 °C, while to study the melting characteristics the bath temperature was set as 31 °C and 36 °C. The freezing and melting time decreased for all the test conditions when the volume percentage of GnP increased. The freezing rate was enhanced by ~43% and ~32% for the bath temperatures of −6 °C and −10 °C, respectively, at 0.5 vol % of graphene loading. The melting rate was enhanced by ~42% and ~63% for the bath temperatures of 31 °C and 36 °C, respectively, at 0.5 vol % of graphene loading.

scholarly journals Evaluation of the Influences of Scrap Melting and Dissolution during Dynamic Linz–Donawitz (LD) Converter Modelling

Processes ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 186 ◽  
Author(s):  
Florian Penz ◽  
Johannes Schenk ◽  
Rainer Ammer ◽  
Gerald Klösch ◽  
Krzysztof Pastucha
Keyword(s):  
Process Model ◽  
Research Work ◽  
Bath Temperature ◽  
Melting Behavior ◽  
Pure Oxygen ◽  
Dissolution Behavior ◽  
Special Focus ◽  
Hot Metal ◽  
Crude Steel ◽  
Scrap Melting

The Linz–Donawitz (LD) converter is still the dominant process for converting hot metal into crude steel with the help of technically pure oxygen. Beside hot metal, scrap is the most important charging material which acts as an additional iron source and coolant. Because of the irrevocable importance of the process, there is continued interest in a dynamic simulation of the LD process, especially regarding the savings of material and process costs with optimized process times. Based on a thermodynamic and kinetic Matlab® coded model, the influences of several scrap parameters on its melting and dissolution behavior were determined, with a special focus on establishing the importance of specific factors on the crude steel composition and bath temperature after a defined blowing period to increase the accuracy of the process model. The calculations reported clearly indicate that the dynamic converter model reacts very sensitively to the chemical composition of the scrap as well as the charged scrap mass and size. Those results reflect the importance of experiments for validation on the diffusive scrap melting model in further research work. Based on that, reliable conclusions could be drawn to improve the theoretical and practical description of the dissolution and melting behavior of scrap in dynamic converter modelling.

Critical Carbon Concentration and Excessively High Bath Temperature for Smelting Ferrochromium in the Argon-Oxygen Furnace

2013 ◽  
Vol 423-426 ◽  
pp. 202-206
Author(s):  
Ming Rong Han ◽  
Long Qiang Huang ◽  
Bi Jia
Keyword(s):  
Artificial Intelligence ◽  
Carbon Dioxide ◽  
Carbon Concentration ◽  
Dynamic Control ◽  
Bath Temperature ◽  
Steel Scrap ◽  
Furnace Temperature ◽  
Artificial Intelligence Technology ◽  
Two Stages ◽  
Double Channel

Some problems have seriously affected the implementation of smelting ferrochromium in the argon-oxygen furnace. This paper discussed reducing chromium loss and controlling excessively high bath temperature by thermodynamic analysis. The results show that the process is divided into two stages and the critical carbon concentration of its switchover point is controlled in the range of 1.5%-2% to reduce chromium loss; dynamic control of oxygen and argon supply by theoretical calculation and AI(Artificial Intelligence) technology and carbon dioxide blown by a lance with double channel as coolant instead of steel scrap and chrome ore can flexibly control furnace temperature.

scholarly journals Traffic Density-Related Black Carbon Distribution: Impact of Wind in a Basin Town

2021 ◽  
Vol 18 (12) ◽  
pp. 6490
Author(s):  
Borut Jereb ◽  
Brigita Gajšek ◽  
Gregor Šipek ◽  
Špela Kovše ◽  
Matevz Obrecht
Keyword(s):  
Black Carbon ◽  
Carbon Concentration ◽  
Ground Level ◽  
Traffic Density ◽  
Carbon Distribution ◽  
Wind Speeds ◽  
Black Carbon Concentration ◽  
Low Wind Speeds ◽  
Temperature Inversions ◽  
Carbon Concentrations

Black carbon is one of the riskiest particle matter pollutants that is harmful to human health. Although it has been increasingly investigated, factors that depend on black carbon distribution and concentration are still insufficiently researched. Variables, such as traffic density, wind speeds, and ground levels can lead to substantial variations of black carbon concentrations and potential exposure, which is even riskier for people living in less-airy sites. Therefore, this paper “fills the gaps” by studying black carbon distribution variations, concentrations, and oscillations, with special emphasis on traffic density and road segments, at multiple locations, in a small city located in a basin, with frequent temperature inversions and infrequent low wind speeds. As wind speed has a significant impact on black carbon concentration trends, it is critical to present how low wind speeds influence black carbon dispersion in a basin city, and how black carbon is dependent on traffic density. Our results revealed that when the wind reached speeds of 1 ms−1, black carbon concentrations actually increased. In lengthy wind periods, when wind speeds reached 2 or 3 ms−1, black carbon concentrations decreased during rush hour and in the time of severe winter biomass burning. By observing the results, it could be concluded that black carbon persists longer in higher altitudes than near ground level. Black carbon concentration oscillations were also seen as more pronounced on main roads with higher traffic density. The more the traffic decreases and becomes steady, the more black carbon concentrations oscillate.

A Study on the smelting process of low carbon steel scrap and sponge iron in medium frequency induction furnace for production of front bumper beams

2021 ◽  
Vol 98 ◽  
pp. 8-13
Author(s):  
Dung Ngo Quoc ◽  
◽  
Viet Nguyen Hoang
Keyword(s):  
Carbon Steel ◽  
Induction Furnace ◽  
Current Trend ◽  
Low Carbon Steel ◽  
Steel Grade ◽  
Sponge Iron ◽  
Smelting Process ◽  
Steel Scrap ◽  
Low Carbon ◽  
Medium Frequency

MS1200 steel grade is now widely utilized in the automotive sector because it is a good solution for the current trend of vehicle chassis frame construction. This research presents a technology procedure for producing MS1200 steel grade from low carbon steel scrap and sponge iron – a product of MIREX Vietnam. The smelting using up to 30 % sponge iron briquettes combined with low carbon scrap, FeSi, FeMn, FeCr, FeTi,… was realized in a medium frequency induction furnace. The heat treatment for forged steel was performed to obtain required properties. The steel product has the following properties: tensile strength σb = 1280 MPa, yield strength σ0.2 = 990 MPa and impact toughness ak = 769 J/mm2, that meets the need of industrial use.

Quantitative determination of carbon concentration profiles by GD-OES for the study of decarburization in low-carbon steels

2015 ◽  
Vol 48 (2) ◽  
pp. 73-81 ◽  
Author(s):  
Henrique Duarte Alvarenga ◽  
Nele Van Steenberge ◽  
Chris Xhoffer ◽  
Patrick Steegstra ◽  
Jilt Sietsma ◽  
...  
Keyword(s):  
Quantitative Determination ◽  
Carbon Concentration ◽  
Carbon Steels ◽  
Concentration Profiles ◽  
Low Carbon ◽  
Low Carbon Steels

scholarly journals Low carbon steel for hot metal deformation tools (review)

2019 ◽  
Vol 89 (1) ◽  
pp. 39-47
Author(s):  
S.V. Bobyr ◽  
◽  
G.V. Levchenko ◽  
Keyword(s):  
Carbon Steel ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Hot Metal ◽  
Metal Deformation
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