| 摘要 |
There is provided a brass free from lead (Pb) and possessing excellent machinability, castability, mechanical properties and other properties. A brass consisting of not less than 55% by weight and not more than 75% by weight of copper (Cu), not less than 0.3% by weight and not more than 4.0% by weight of bismuth (Bi), and y% by weight of boron (B) and x% by weight of silicon (Si), y and x satisfying the following requirements: 0 ‰¤ x ‰¤ 2.0, 0 ‰¤ y ‰¤ 0.3, and y > -0.15x + 0.015ab, wherein a is 0.2 when Bi is 0.3% by weight ‰¤ Bi < 0.75% by weight; 0.85 when Bi is 0.75% by weight ‰¤ Bi < 1.5% by weight; and 1 when Bi is 1.5% by weight ‰¤ Bi ‰¤ 4.0% by weight, b is 1 when the apparent content of zinc (Zn) is not less than 37% and less than 41%; and 0.75 when the apparent content of Zn is not less than 41% and not more than 45%, the balance consisting of Zn and unavoidable impurities, is excellent in castability, as well as, for example, in machinability and mechanical properties. |
