Basic Actions to Prevent Continuous Casting Defects of Billets

Author(s):  
D. Di Napoli Guzela ◽  
J. Bolota ◽  
M. Stuart Nogueira ◽  
J. Britti Bacalhau
2000 ◽  
pp. 119-148

Abstract This chapter describes various aspects of the billet making process and how they affect the quality of aluminum extrusions. It begins with an overview of the direct-chill continuous casting technique and its advantages over other methods, particularly for hard aluminum alloys. It then discusses the influence of casting variables, including pouring temperature and cooling rate, and operating considerations such as the make-up of charge materials, fluxing and degassing procedures, and grain refining. The chapter also provides information on vertical and horizontal casting systems, billet homogenization, and the cause of casting defects, including cracking and splitting, segregation, porosity, and grain growth.


2013 ◽  
Vol 331 ◽  
pp. 487-491
Author(s):  
Qin Zhang ◽  
Zhuo Cao ◽  
Ying Li ◽  
Jian Zhong Cui

Using electromagnetic horizontal continuous casting method, A trial was carried out on producing (Φ54mm) 1560 nickel-based alloy round ingot. Examinations are also proceed on properties of a series of 1560 alloy wires and rods that made from the ingot by further rolling and drawing. The results show that the central area of ingot produced by electromagnetic horizontal casting is composed of uniform equiaxed grains, Some casting defects that usually occur in conventional horizontal continuous casting , such as central crackshrinkage cavity and porosity are restrained. Meanwhile, the segregation of solutes was reduced significantly. This technique shorten the conventional production process by eliminating annealingforging and sanding operation, which can greatly enhance the production yield.


2009 ◽  
Vol 106 (6) ◽  
pp. 242-247
Author(s):  
C. Damerval ◽  
H. Tavernier ◽  
L. Avedian ◽  
P. Disant ◽  
P. Delfosse ◽  
...  

Author(s):  
A. T. Kunakbaeva ◽  
A. M. Stolyarov ◽  
M. V. Potapova

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.


Sign in / Sign up

Export Citation Format

Share Document