CW617 is lead brass. Lead brass is an extremely important and most widely used complex brass with excellent cutting performance and wear resistance. Lead brass contains less than 3% lead, and a small amount of Fe, Ni or Sn is often added. Ph exists in a free state in the tissue, which splits the matrix, making the lead brass have good machinability and anti-friction properties.
Lead brass is a complex brass with lead as the main additive element. It is a combination of four non-ferrous metals such as Cu, Pb, Al, and Zn in a certain proportion. Lead rarely dissolves in the copper-zinc alloy, and exists as an independent phase in the alloy. It is distributed as free particles in the grain boundary and within the grain. It not only has a lubricating effect, but also makes the chips broken into pieces, which can improve the machinability of brass. And abrasion resistance.
The machinability of lead brass is directly proportional to the lead content, but when the lead content exceeds 3%, the machinability of copper is no longer significantly improved, and the hardness, strength and elongation of the brass are reduced. Therefore, the main properties of lead brass can be summarized as wear resistance, corrosion resistance and good toughness.
Lead brass (commonly known as free-cutting brass): Lead is actually insoluble in brass and is distributed on grain boundaries in the state of free particles. According to its organization, lead brass has two types: α and (α+β). Due to the harmful effects of lead, alpha-lead brass has very low high temperature plasticity, so it can only be cold deformed or hot extruded. (Α+β) Lead brass has good plasticity at high temperature and can be forged.
