The concept and classification of brass
Brass is mainly an alloy composed of copper and zinc. It is characterized by high wear resistance, high strength, hardness, chemical corrosion resistance and good cutting processability. Brass often undergoes quaternary cracking (stress corrosion cracking), which is obvious in ammonia, ammonia water or sulfuric acid. There are three reasons for quarterly cracking of brass. One is pitting corrosion (electrochemical corrosion), the other is dezincification, and the third is residual stress.
①With the addition of Zn, it is composed only of copper and zinc, and is called ordinary brass. It is used to make copper plates, copper tubes, etc.
② Adding Pb, in addition to copper and zinc, also contains lead, the cutting performance is particularly good, it is called fast cutting brass, has good castability and good fluidity.
③Add Sn, in addition to copper and zinc, there is also tin, which is corrosion-resistant and used in marine climates.
④Add AI to improve strength, hardness, and corrosion resistance in the atmosphere, and can be used to manufacture corrosion-resistant parts.
⑤Add Si to improve mechanical properties, corrosion resistance and wear resistance, and can be used to manufacture marine ship parts and chemical machinery parts.
⑥ Add Mn, such as 58-4 (L105), which is often used as solder and has good high temperature wettability.
⑦ Adding Ni has good heat resistance and corrosion resistance.
⑧ Adding Fe has good heat resistance and corrosion resistance.
