Theory and Experimental Research on Inclusion Modification in Improved Carbon Structural Steel

2010 ◽  
Vol 146-147 ◽  
pp. 1659-1666
Author(s):  
Cai Jun Zhang ◽  
Li Guang Zhu ◽  
Dong Mei Tu ◽  
Shuo Ming Wang ◽  
Hui Ding
Keyword(s):  
Carbon Steel ◽  
Experimental Research ◽  
Calcium Treatment ◽  
Sulfur Activity ◽  
High Quality ◽  
Steel Temperature ◽  
Aluminum Activity ◽  
Molten Steel Temperature ◽  
Inclusion Modification ◽  
Carbon Structural Steel

By means of the thermodynamics analysis of inclusion modification in the process of calcium treatment, and the advantage area chart of calcium, aluminum, sulfur, oxygen activity in inclusion midification, this paper analyzes the effects of molten steel temperature, aluminum activity, sulfur activity and other factors on inclusion modification. After calcium treatment, inclusions in high-quality carbon steel S48 will become massive or globular calcium aluminate, MnS inclusion and the composite inclusions of MgO·Al2O3 in kernel and CaO·Al2O3 in shell.

scholarly journals A Kinetic Model for the Modification of Al2O3 Inclusions during Calcium Treatment in High-Carbon Hard Wire Steel

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1305
Author(s):  
Zuobing Xi ◽  
Changrong Li ◽  
Linzhu Wang
Keyword(s):  
Kinetic Model ◽  
Early Stage ◽  
Morphological Evolution ◽  
Product Layer ◽  
Melting Time ◽  
Calcium Treatment ◽  
High Carbon ◽  
Inclusion Modification ◽  
Shrinking Core ◽  
Wire Steel

Laboratory-scale experiments for the modification of Al2O3 inclusions by calcium treatment in high-carbon hard wire steel were performed and the compositions and morphological evolution of inclusions were studied. The kinetics of the modification of Al2O3 inclusions by calcium treatment were studied in high-carbon hard wire steel based on the unreacted shrinking core model, considering the transfer of Ca and Al through the boundary layer and within the product layer, coupled with thermodynamic equilibrium at the interfaces. The diffusion of Al in the inclusion layer was the limiting link in the inclusion modification process. The Ca concentration in molten steel had the greatest influence on the inclusion modification time. The modification time for inclusions tended to be longer in the transformation of higher CaO-containing calcium aluminate. The modification of Al2O3 into CA6 was fastest, while the most time was needed to modify CA into C12A7. It took about six times time longer at the later stage of inclusion modification than at the early stage. The complete modification time for inclusions increased with the square of their radii. The changes of CaO contents with melting time were estimated based on a kinetic model and was consistent with experimental results.

Temperature Prediction Model for Molten Steel in RH Refining Process

2013 ◽  
Vol 712-715 ◽  
pp. 22-25 ◽  
Author(s):  
Tia Xia ◽  
Zhu He
Keyword(s):  
Mathematical Model ◽  
Prediction Model ◽  
Molten Steel ◽  
Initial Temperature ◽  
Refining Process ◽  
Temperature Prediction ◽  
Steel Temperature ◽  
Molten Steel Temperature

A mathematical model for the RH refining process was developed and validated by the measured molten steel temperature in situ. It is showed that the model predicted temperature matched the measured value well and the average errors within ±5°C were 86.9%. The model results also showed that for every increase of 100°C of the initial temperature of the chamber inwall , the average molten steel temperature increased by about 8°C. For every blowing extra 50m3 oxygen, the steel temperature increased by about 7°C.

scholarly journals THE STATE OF FORMATION OF ADOLESCENTS’ COORDINATION QUALITIES IN THE PROCESS OF TEACHING MODERN DANCE

2021 ◽  
Vol 8 (44) ◽  
pp. 62
Author(s):  
N. M. Кholchenkova
Keyword(s):  
Physical Health ◽  
Experimental Research ◽  
Motor Coordination ◽  
Effective Means ◽  
Modern Dance ◽  
The State ◽  
Educational Process ◽  
Children And Youth ◽  
High Quality ◽  
Biomechanical Features

In the article modern dance is defined as an effective means of healthcare of children and youth in the educational process. The development of physical qualities, such as motor coordination, has a great importance for the high-quality performing of modern dance techniques and skills.The pedagogical and biomechanical features of teaching the basic motor elements of modern dance are revealed in the work. The results of the formation of statodynamic stability’s parameters in the structure of coordination qualities of younger adolescents are presented. The control took place with the use of a modern stabilographic complex at the ascertaining stage of the experimental research using the author's method of teaching modern dance.Key words: healthcare, coordination qualities, stability, modern dance, physical health.

scholarly journals IMPROVING WATERPROOFING PROPERTIES IN THE WALL BASEMENT AREA BY INJECTION METHOD

2019 ◽  
Vol 2 (53) ◽  
pp. 122-127
Author(s):  
Olena Filonenko ◽  
Maryna Leshchenko ◽  
Olesia Rozdabara ◽  
Oleksandr Duka ◽  
Vlad Pashchenko ◽  
...  
Keyword(s):  
Experimental Data ◽  
Moisture Content ◽  
Experimental Research ◽  
High Quality ◽  
Injection Method ◽  
Wall Area

The article is focused on the natural experimental research of injection waterproofing impact on basement areas of existingbuildings brick walls. Two types of experimental installations for waterproofing material injection have been developed. Thesecond type turned out to be more efficient due to the fact that it could cover larger waterproofing wall area. It can possiblyspeed up the process of walls waterproofing and major repairs of buildings in general. According to the experimental data, after the injection waterproofing placement, the wall moisture content decreased by half due to the high quality waterproofingmaterial and performed installation work.

Experimental research on the deep-hole boring of pure niobium tube

2020 ◽  
Vol 234 (8) ◽  
pp. 1124-1132
Author(s):  
Xiaolan Han ◽  
Zhanfeng Liu ◽  
Yazhou Feng
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
Experimental Research ◽  
Process Parameters ◽  
Cutting Tool ◽  
Geometric Parameters ◽  
Deep Hole ◽  
High Quality ◽  
Pure Niobium ◽  
Hole Axis

In the deep-hole boring process on pure niobium tube, there exist some problems including serious tool wear, tough chips, and poor surface quality. In order to bore high-quality deep holes on rolled niobium tube, the cutting tool structure and boring process parameters suitable for machining rolled niobium tube were designed and two experimental schemes were proposed. The results showed that the geometric parameters of the cutting tool and process parameters have important influences on the tool wear, chip morphologies, hole-axis deflection, and hole surface roughness. By adjusting the geometric parameters of the cutting tool and boring process parameters, reasonable geometric parameters of the cutting tool and boring process parameters were obtained.

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