Knowledge of copper industry production processes
1. Upward continuous casting process
Upward continuous casting is to introduce the molten metal in the holding furnace directly into the water-cooled crystallizer through the liquid flow control device, solidify it into a solidified shell with a certain strength, and then use the vertical outward pulling force applied by the ingot rod and the traction roller to continuously pull the solidified copper rod out of the crystallizer, forming a continuous casting process. This casting method is called upward continuous casting.
Advantages: high production efficiency, short production cycle, low processing cost; simple operation, low labor intensity; simple equipment, small footprint, low investment, high economic benefits.
Disadvantages: The central structure of the organization is easy to loose, not suitable for high-strength products, and not suitable for small batch production.
2. Continuous extrusion process
The continuous extrusion process uses particles or rods as billets, cleverly utilizes the friction between the deformed metal and the tool, and is composed of a rectangular section groove on the rotating extrusion wheel and a fixed die seat. The annular channel, when the extrusion wheel rotates, continuously feeds the rod-shaped billet with the help of the friction on the groove wall to achieve continuous extrusion.
Advantages: Using the upper lead rod as raw material, there is no extrusion excess, high material utilization rate, generally up to 95%, good uniformity of organizational properties, good finish, suitable for both large-scale and small-scale production.
Disadvantages: Cannot eliminate the quality problems caused by raw materials.
3. Rolling process
Our company's rolling production mainly includes cold rolling.
Cold rolling refers to the production method of rolling the ingot without heating. There is only work hardening effect during deformation, and there is no recovery and recrystallization phenomenon. Cold rolling has the disadvantages of high metal deformation resistance, relatively small pass processing rate, and high deformation energy consumption.
Common rolling defects include: cracks, cracked edges, tolerance runout, poor plate shape (single-side wave, two-rib wave), stress lines, transverse roller marks, etc. Therefore, reasonable roller shape, rolling force, rolling pass and processing rate in the rolling process are the key to determining product quality.
4. Annealing process
Heat the product to an appropriate temperature, take different holding times according to different materials, and then slowly cool it down. The purpose is to eliminate or reduce the uneven chemical composition inside the grains, so that the internal structure of the metal reaches or approaches a balanced state, and obtains good process performance and performance.
Annealing is divided into stress relief annealing, recrystallization annealing, homogenization annealing, etc. The heating temperature of stress relief annealing is lower than the recrystallization temperature; the recrystallization annealing temperature is above the recrystallization temperature line; the homogenization annealing temperature is below the solid phase point (pay attention to prevent overburning). Our company's annealing process mainly uses bell furnace, bright furnace, and air cushion furnace.
Common quality defects of annealing: overburning caused by too high temperature and too long holding time, uneven performance, oxidation blackening caused by atmosphere inclusions, etc. Therefore, the atmosphere ratio, annealing temperature, and holding time must be strictly controlled during the production process.
