What are the key points of production technology of copper sheet and brass sheet and strip?
Release time:2021-04-16Click:1051
Copper is a relatively pure copper, generally can be considered as pure copper, conductivity, plasticity are good, but the strength, hardness is worse. Red Copper has excellent heat conductivity, ductility and corrosion resistance. The trace impurities in red copper have a serious influence on the electrical and thermal conductivity of copper. Titanium, phosphorus, iron, silicon and so on obviously reduced the conductivity, but cadmium, zinc and so on has the very small influence. The solubility of sulfur, selenium and tellurium in copper is very small, and brittle compounds can be formed with copper.
The main points of the production technology of copper plate and strip are as follows:
1. INGOT heating. Copper ingots tend to oxidize on the surface when heated, and non-oxygen ingots tend to permeate oxygen when heated. Therefore, when heating should be used in general micro-reduction (more for oxygen-free copper, oxygen-rich copper due to easy "hydrogen disease" and should not be used) or neutral atmosphere, should maintain positive pressure furnace. Heating should be taken to quickly raise the temperature, low temperature out of the furnace.
2. Hot Rolling. The hot rolling of RED COPPER INGOT should adopt low temperature, fast and large processing rate to reduce high temperature oxidation.
3. Cold Rolling. The plasticity of red copper is good, the cold working rate between two annealing can reach over 95% . Therefore, the intermediate annealing is not necessary in the cold rolling process.
4. Finished annealing. Red Copper is easy to oxidize when returning, so it needs to be carried out in the annealing furnace with protective atmosphere.
5. Cleaning and finishing. The surface of red copper strip is easy to change color, it should be cleaned and passivated in time. Copper relatively soft, should take measures (such as lining paper) to prevent scratch. When cutting, carefully adjust the pressure of the tool to prevent indentation.
Brass is an alloy of copper and zinc. A brass composed of copper and zinc is called ordinary brass. An alloy composed of more than two elements is called special brass. Brass has strong wear resistance, brass is often used in the manufacture of valves, water pipes, air-conditioning inside and outside the connecting pipe and radiator.
The main points of brass plate and strip production process are as follows:
1. INGOT heating. HIGH-ZINC BRASS is easy to "dezincification" at high temperature, and some complex brass have large casting stress, therefore, most brass should not be heated quickly at high temperature. The micro-oxidation atmosphere should be used in the furnace.
2. Hot Rolling. Some brass (such as high zinc brass) in high temperature in addition to the brittle phase, hot rolling is best to avoid brittle temperature zone, so as to avoid cracking. Low Zinc simple brass (such as H96, H90, etc.) has good shape and can be hot rolled in a large temperature range, while some complicated brass such as lead brass have limited plasticity at high temperature, so the temperature range of hot rolling is narrow, it is necessary to carry out rapid rolling and pay attention to temperature drop.
3. Cold Rolling. Simple brass also has quite good plasticity, processing rate can reach more than 75% , and most complex brass plasticity is poor, some processing rate less than 50% . Therefore, the total processing rate should be designed to leave a point, so as not to crack edge, broken band.
4. ANNEAL. Some brass (such as HPb59-1, H62, etc.) are sensitive to internal stress and should be annealed within 24 hours after cold working to avoid cracking or deforming due to internal stress. FOR HIGH-ZINC BRASS, the lower limit of annealing temperature should be taken to prevent high-temperature dezincification, so that the products appear "pitted surface" defects. Because casting brass in the role of both degassing zinc, metal air content is less, so annealing higher. Cleaning and finishing. Brass pickling, acid concentration should not be too high time should not be too long to avoid pickling surface "dezincification. ". High-zinc brass hard products and semi-hard products should not be straightened repeatedly, otherwise stress relief annealing must be carried out in time.
Source: Web Collation
- Previous:Detailed explanation of casting technology, including vertical semi-continuous casting, vertical full continuous casting, horizontal continuous casting, upward continuous casting and so on
- Next:The contradiction between supply and demand is not prominent, why does the battle for the high price of copper become more and more fierce?