This article focuses on the regulation of the casting speed of ingots and expounds the basic principles of regulating the casting speed of ingots, that is, under the premise of ensuring that the quality of ingots meets the technical conditions and the yield rate, the casting speed should be increased as much as possible to maximize the production capacity of the casting machine. The principles of casting speed control for flat ingots, small-diameter and large-cross-section round ingots, hollow round ingots, and different casting methods were analyzed respectively. The close relationship between casting speed and alloy chemical composition was pointed out, aiming to provide a theoretical basis for the reasonable control of casting speed in actual production.
I. Introduction
Casting is one of the important processes in metal processing. The quality of ingots directly affects the performance and quality of subsequent processed products. Casting speed, as a key parameter in the casting process, has a significant impact on the quality of ingots and the production capacity of casting machines. Reasonable regulation of the casting speed can not only ensure that the quality of the ingot meets the technical requirements, but also improve the production efficiency. Therefore, it is of great practical significance to study the regulation principles of the casting speed of ingot.
Ii. General Principles for Regulating the Casting Speed of Ingots
The core principle of regulating the casting speed of ingots is to increase the casting speed as much as possible on the basis of ensuring that the quality of ingots meets the technical conditions (including the yield rate), so as to fully exert the maximum production capacity of the casting machine. This principle runs through the casting process of different types of ingots and serves as the basis for formulating specific casting speed control plans.
Iii. Principles for Regulating the Casting Speed of Different Types of Ingots
3.1 Flat ingots
For flat ingots, the primary consideration in choosing the casting speed is to avoid cracks in the ingot. The tendencies of cold cracking and hot cracking vary among different alloys, and the principles for regulating their casting speeds also differ. For soft alloys without a tendency for cold cracking, as the width-to-thickness ratio of the ingot increases, the casting speed should be reduced. For hard alloys with a greater tendency of cold cracking, the casting speed should be increased as the width-to-thickness ratio of the ingot increases. When the thickness and width-to-thickness ratio of the ingot are fixed, for alloys with a greater tendency to develop hot cracks, the casting speed should be reduced. This is because the width-to-thickness ratio and alloy properties can affect the stress distribution and cooling rate of the ingot during the casting process, thereby influencing the formation of cracks.
3.2 Round ingots
3.2.1 Small diameter and large cross-section round ingots
Due to the small crack tendency and the absolute size of the transition zone of small-diameter round ingots, a higher casting speed can be selected under the condition of ensuring good surface quality of the ingot. On the contrary, for large cross-section round ingots, a lower casting speed should be adopted. For the same alloy, the larger the diameter of the ingot, the lower the casting speed. This is because large-diameter ingots have a slower cooling rate during the casting process, and the internal stress distribution is complex, making them prone to defects such as cracks. Reducing the casting speed can decrease the occurrence of these problems.
3.2.2 Different alloy round ingots
When the diameters of the ingots are the same, The casting speed is classified according to soft alloys (industrial pure aluminum, 3A21, 5A02, etc.), 6000 series alloys (6063, 6061, 6A02, etc.), high magnesium alloys (5A05, 5A06, 5056, etc.), high content 2000 series alloys (2A11, 2A12, 2B11, etc.), and high content 7000 series alloys (7075, 7A0 The order of 4, 7A09, etc. decreases in descending order. The chemical composition and physical properties of different alloys vary, and so do their hot cracking tendencies and fluidity. Therefore, the casting speed needs to be adjusted according to the type of alloy.
3.3 Hollow round ingots
For hollow round ingots, under the conditions of the same alloy and outer diameter, the casting speed increases with the increase of wall thickness. Under the condition that the alloy and inner diameter are the same, the casting speed decreases as the wall thickness increases. Under the same other conditions, the casting speed of soft alloy hollow round ingots is approximately 30% higher than that of solid round ingots with the same outer diameter, and the casting speed of hard alloy hollow round ingots is approximately 50% to 100% higher than that of solid round ingots with the same outer diameter. This is because the wall thickness of hollow round ingots and the alloy properties will affect their heat dissipation and stress distribution, thereby influencing the selection of casting speed.
Iv. The Influence of Different Casting Methods on Casting Speed
When performing hot top casting, oil vapor slide casting and electromagnetic casting, under the same other conditions, the casting speeds are respectively approximately 10%-20%, 15%-25% and 20%-30% higher than those of ordinary casting. These advanced casting methods increase the casting speed by improving the solidification conditions of the ingots and the heat transfer process, thereby enhancing production efficiency.
V. The Influence of Alloy Chemical Composition on Casting Speed
The regulation of casting speed is highly related to the chemical composition of the alloy. For the same alloy, under the condition that other process parameters remain unchanged, adjusting the chemical composition of the alloy can increase the allowable casting speed to ensure that the ingot does not develop cracks. This is because the alloying chemical components will affect the physical properties of the alloy such as its melting point, fluidity, and coefficient of thermal expansion, and thereby influence the solidification behavior and stress distribution of the ingot during the casting process.
Vi. Conclusion
The regulation of the casting speed of ingots is a complex process that requires comprehensive consideration of multiple factors such as the type of ingot, the chemical composition of the alloy, and the casting method. In actual production, the appropriate casting speed control principle should be selected based on specific circumstances to ensure the quality of ingots and production efficiency. At the same time, we should constantly research and explore new casting processes and methods for adjusting the chemical composition of alloys, further optimize the control of casting speed, and improve the quality of ingots and production efficiency.
Through the research on the principles of regulating the casting speed of different types of ingots, we can better understand the interrelationships among various factors in the casting process and provide scientific guidance for actual production. Future research can further delve into the quantitative relationship between alloy chemical composition and casting speed, as well as the impact of new casting processes on casting speed and ingot quality, providing more powerful support for the development of the casting industry.
