Thermodynamics and Dynamics of Nitrogen Increasing in LF Refining Process

2012 ◽  
Vol 538-541 ◽  
pp. 2387-2391
Author(s):  
Zheng De Ren ◽  
Sheng Qin Zhang ◽  
Zhu Bing Gao ◽  
Qian Ying Zhang
Keyword(s):  
Reaction Mechanism ◽  
Liquid Steel ◽  
Refining Process ◽  
High Grade ◽  
Dissolved Nitrogen ◽  
Foam Slag ◽  
Factors Of Influence ◽  
Thermodynamics And Dynamics ◽  
Lf Refining ◽  
Grade Steel

Nitrogen is one of harmful elements in liquid steel. Reducing nitrogen quantity is required for making high-grade steel. This paper analyzes the reaction mechanism of nitrogen increasing through the methods of metallurgical thermodynamics and dynamics. In liquid steel dissolved nitrogen and nitrides are the main forms of nitrogen. The factors of influence on nitrogen increasing are temperature, kinds and quantity of the alloying elements in the liquid steel, , the lifetime of foam in foam slag, the quantity of flow of argon and so on. Analytical results of metallurgical thermodynamics and dynamics are verified by measuring nitrogen content in the links of LF refining process of new developed area of Chongqing steel and iron Co.Ltd.

Through-wall yield ductile burst pressure of high-grade steel tube and casing with and without corroded defect

2020 ◽  
pp. 102902
Author(s):  
Deng Kuanhai ◽  
Peng Yang ◽  
Liu Bing ◽  
Lin Yuanhua ◽  
Wang Jiandong
Keyword(s):  
Steel Tube ◽  
Burst Pressure ◽  
High Grade ◽  
Grade Steel

scholarly journals 3D Integrated Modeling of Supersonic Coherent Jet Penetration and Decarburization in EAF Refining Process

Processes ◽  
2020 ◽  
Vol 8 (6) ◽  
pp. 700
Author(s):  
Yuchao Chen ◽  
Armin K. Silaen ◽  
Chenn Q. Zhou
Keyword(s):  
Liquid Steel ◽  
Flow Characteristics ◽  
Bath Temperature ◽  
Integrated Model ◽  
Refining Process ◽  
Computational Time ◽  
Reacting Flow ◽  
Two Phase ◽  
Decarburization Rate ◽  
Coherent Jet

The present study proposes a complete 3D integrated model to simulate the top-blown supersonic coherent jet decarburization in the electric arc furnace (EAF) refining process. The 3D integrated model avoids the direct simulation of the supersonic coherent jet interacting with the liquid steel bath and provides a feasible way to simulate the decarburization in the liquid steel-oxygen two-phase reacting flow system with acceptable computational time. The model can be used to dynamically predict the details of the molten bath, including 3D distribution of in-bath substances, flow characteristics and bath temperature and provide a basis for optimizing the decarburization rate or other required parameters during the refining process.

Inclusions evolution during the LF refining process of 439 ultra-pure ferritic stainless steel

2019 ◽  
Vol 116 (6) ◽  
pp. 619
Author(s):  
Xingrun Chen ◽  
Guoguang Cheng ◽  
Yuyang Hou ◽  
Jingyu Li
Keyword(s):  
Stainless Steel ◽  
Ferritic Stainless Steel ◽  
Refining Process ◽  
Stable Phase ◽  
X Ray ◽  
Titanium Aluminum ◽  
Reasonable Range ◽  
Ti Addition ◽  
Automatic Scanning ◽  
Lf Refining

The morphology, composition, size, and number of inclusions in 439 ultra-pure ferritic stainless steel samples were analyzed using an automatic scanning electron microscope combined with an energy-dispersive X-ray spectrometer. In addition, the appropriate contents of titanium, aluminum, and calcium were analyzed through the coupling of thermodynamics calculation and experimental results. CaO-Al2O3-MgO inclusions existed in the 439 steel before Ti additions in the ladle furnace (LF) refining process. After Ti addition in the LF refining process, the inclusions were transformed into CaO-Al2O3-MgO-TiOx inclusions. The evolution of these inclusions was consistent with thermodynamic calculation, which indicated that when the Al, Ca, and Ti contents were within a reasonable range, Ca treatment could significantly modify the aluminate and spinel to form CaO-Al2O3-MgO liquid inclusions. In addition, the compositions of inclusions after the addition of titanium were mostly located in the Al2O3-TiOx stable phase. The collision of the CaO-Al2O3-MgO liquid inclusions and Al2O3-TiOx inclusions resulted in the modification of the CaO-Al2O3-MgO-TiOx inclusions. The compositions of most inclusions were located in the liquid zone. The control range of the aluminum, calcium, and titanium contents was obtained: logAl% ≥ 1.481logTi% − 0.7166, Ca% ≥ 34.926(Al%)3 − 3.3056(Al%)2 + 0.1112(Al%) − 0.0003.

Study on Experiment and Mechanism of Bottom Blowing CO2During the LF Refining Process

2013 ◽  
Vol 85 (4) ◽  
pp. 589-598 ◽  
Author(s):  
Yunling Gu ◽  
Haijuan Wang ◽  
Rong Zhu ◽  
Jing Wang ◽  
Ming Lv ◽  
...  
Keyword(s):  
Refining Process ◽  
Bottom Blowing ◽  
Lf Refining

Analysis of Research Topic on Cement Cold-Recycled Base of High-Grade Highways

2012 ◽  
Vol 204-208 ◽  
pp. 1730-1735
Author(s):  
Tao Liu ◽  
Tu Zhang Ming ◽  
Guang Wei Hu
Keyword(s):  
Cement Hydration ◽  
Research Topic ◽  
Fatigue Properties ◽  
High Grade ◽  
Aggregate Gradation ◽  
Evaluation Indexes ◽  
Fine Aggregates ◽  
Factors Of Influence ◽  
The Difference ◽  
Aggregate Base

This review presents the difference between cement cold-recycled base and cement-stabilized new aggregate base. Old aggregate gradation is obviously beyond the prescribed limits. Due to old cement hydration products, the gradation of old mixture is not real by screening test, just called it “Fake Gradation”. The various factors of influence on pavement performances are introduced, including cement content, gradation, fine aggregates content, old material characteristic and water loss ratio. The main pavement perforamnce, such as mechanical properties, shrinkage properties and fatigue properties of cement cold-recycled mixture may not meet the requirement of high grade highways. The research topic of cement cold-recycled base is pointed out, which includes properties of old materials, the application of additives, the methods of improving pavement perforamnce and the establishment of pavement performances evaluation indexes, etc.

Corrosion Assessment Method Validation for High-Grade Line Pipe

2010 ◽  
Author(s):  
Michael Besel ◽  
Steffen Zimmermann ◽  
Christoph Kalwa ◽  
Theo Ko¨ppe ◽  
Andreas Liessem
Keyword(s):  
Plastic Flow ◽  
Predictive Accuracy ◽  
Plastic Material ◽  
Assessment Method ◽  
Burst Pressure ◽  
High Grade ◽  
Line Pipe ◽  
Corrosion Defect ◽  
Von Mises Plasticity ◽  
Grade Steel

The present paper deals with the pressure containment and deformation capacity of corroded high-grade steel line pipe. Firstly, some well established models are investigated concerning their predictive accuracy if applied to high-grade line pipe steel. In particular, it will be shown that all models under consideration tend to overestimate the remaining strength in the case of high-grade steel pipes. Afterwards, FE-analyses are performed in order to study the local evolution of plastic flow in the area of the corrosion defect; at the same time, the burst pressure is predicted applying von Mises plasticity and a simple failure criterion. Although different defect geometries are associated with well pronounced differences in the evolution of the plastic flow around the corrosion defect no significant effect on the burst pressure is found. Finally, the main results of a hydrostatic burst test performed on a pristine X100 line pipe joint are presented. It appears that the material under consideration seems to have anisotropic plastic material properties which may have effect on burst pressure.

scholarly journals Effect of Na2O and Rb2O on Inclusion Removal in C96V Saw Wire Steels Using Low-Basicity LF (Ladle Furnace) Refining Slags

Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 691 ◽  
Author(s):  
Changyong Chen ◽  
Zhouhua Jiang ◽  
Yang Li ◽  
Meng Sun ◽  
Kui Chen ◽  
...  
Keyword(s):  
Melting Zone ◽  
Refining Process ◽  
Ladle Furnace ◽  
Refining Slag ◽  
Dramatic Decrease ◽  
Inclusion Removal ◽  
Wire Steel ◽  
Al2o3 Inclusion ◽  
Lf Refining ◽  
Slag Entrapment

Inclusion removal and modification of C96V saw wire steel using Na2O- and Rb2O- containing novel low-basicity LF (ladle furnace) Refining Slags have been researched. The results indicated that the addition of Na2O deteriorates inclusion removal; by contrast, the addition of Rb2O seems to significantly enhance inclusion removal. In detail, Rb2O can improve the cleanliness in the as-quenched C96V saw wire steel melts compared to preexisting synthetic LF refining slag compositions: (i) The average inclusion diameter experienced a remarkable decrease after reaction between the liquid steel and the synthetic LF refining slag; (ii) In addition, the number of inclusions also suffered from a dramatic decrease, with the reaction time increasing from 900 to 2700 s (15 to 45 min); (iii) Furthermore, both of the MnO-SiO2-Al2O3 and CaO-SiO2-Al2O3 inclusion system mainly concentrated in the low melting zone when the composition of Rb2O in synthetic refining slag was ≥5.0 wt%. This is mainly because Na2O significantly reduces the viscosity of refining slag, while Rb2O increases it. Then, there are two remarkable influences causing the increase of viscosity of refining slag with the addition of Rb2O: the inclusions can be sufficiently entrained within the slag once absorbed due to the significant increase in the viscosity; and the slag entrapment during refining process weakened dramatically.

Sustainable practices for bridge structures

2021 ◽  
Author(s):  
Harminder Singh
Keyword(s):  
Reinforced Concrete ◽  
Environmental Economic ◽  
Social Aspects ◽  
Weathering Steel ◽  
High Grade ◽  
Sustainable Practices ◽  
Planning Stage ◽  
Bridge Structures ◽  
Grade Steel ◽  
Current Practices

<p>On a typical project, the sustainability requirements of bridges should be considered from the planning stage or earlier. In recent years, a lot of research has been undertaken to improve the durability of reinforced concrete and with the use of high-grade steel and weathering steel, the sustainability aspects of bridges have significantly improved. To ensure sustainability in bridges, the already available framework of sustainability covering environmental, economic and social aspects can be implemented. There are several other frameworks and guidelines available from different countries about the sustainability requirements that can be useful for bridges. The paper presents a brief overview of sustainability in bridges, current practices and areas of emerging and future opportunities to improve sustainability.</p>

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