The Numerical Solution of a Continuous Casting Problem

Free-cutting steel gains specific working properties thanks to the high content of sulfur and phosphorus. These elements, especially sulfur, have a rather high tendency to segregation. Therefore, segregation defects in free-cutting steel continuously cast billets can be significantly developed. The aim of the work was to study the influence of the chemical composition of freecutting steel and casting technological parameters on the quality of the macrostructure of continuously cast billets. A metallographic assessment of the internal structure of cast metal made of free-cutting steel and data processing by application of correlation and regression analysis were the research methods. The array of production data of 43 heats of free-cutting steel of grade A12 was studied. Steel casting on a five-strand radial type continuous casting machine was carried out by various methods of metal pouring from tundish into the molds. Metal of 19 heats was poured with an open stream, and 24 heats – by a closed stream through submerged nozzles with a vertical hole. High-quality billets had a cross-sectional size of 150×150 mm. The macrostructure of high-quality square billets made of free-cutting steel of A12 grade is characterized by the presence of central porosity, axial segregation and peripheral point contamination, the degree of development of which was in the range from 1.5 to 2.0 points, segregation cracks and strips – about 1.0 points. In the course of casting with an open stream, almost all of these defects are more developed comparing with the casting by a closed stream. As a result of correlation and regression analysis, linear dependences of the development degree of segregation cracks and strips both axial and angular on the sulfur content in steel and on the ratio of manganese content to sulfur content were established. The degree of these defects development increases with growing of sulfur content in steel of A12 grade. These defects had especially strong development when sulfur content in steel was of more than 0.10%. To improve the quality of cast metal, it is necessary to have the ratio of the manganese content to the sulfur content in the metal more than eight.

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Backscattering Analysis of Cylinder Shaped Scatterer in Vegetation Medium: Comparison Between Theories

Journal of Engineering Technology and Applied Physics ◽

10.33093/jetap.2020.2.1.3 ◽

2020 ◽

Vol 2 (1) ◽

pp. 15-18

Author(s):

Syabeela Syahali ◽

Ewe Hong Tat ◽

Gobi Vetharatnam ◽

Li-Jun Jiang ◽

Hamsalekha A Kumaresan

Keyword(s):

Numerical Solution ◽

Cross Section ◽

Traditional Method ◽

Microwave Remote Sensing ◽

Solution Model ◽

Complex Nature ◽

Good Match ◽

Equivalent Source ◽

Backscattering Cross Section ◽

Method Model

This paper analyses the backscattering cross section of a cylinder both using traditional method model and a new numerical solution model, namely Relaxed Hierarchical Equivalent Source Algorithm (RHESA). The purpose of this study is to investigate the prospect of incorporating numerical solution model into volume scattering calculation, to be applied into microwave remote sensing in vegetation area. Results show a good match, suggesting that RHESA may be suitable to be used to model the more complex nature of vegetation medium.

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Resolution of Off-Centered Sulfide Segregation in High-Carbon Automotive Steel During Continuous Casting With Vertical Bending Slab Casters

AISTech2020 Proceedings of the Iron and Steel Technology Conference ◽

10.33313/380/160 ◽

2020 ◽

Author(s):

R. Sangwai ◽

V. Mahashabde ◽

P. Palai

Keyword(s):

Continuous Casting ◽

High Carbon ◽

Automotive Steel ◽

Sulfide Segregation

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