| 摘要 |
<p>A brass that not containing lead, excels in cutting performance, castability, mechanical properties, etc. This brass is characterized by having a crystal structure wherein the ratio of the sum of a-phase and ß-phase is 85% or higher and containing 55 to less than 75 wt.% of Cu, 0.3 to 4.0 wt.% of Bi, and amounts of B and Si satisfying the relationships of, providing that the amounts of B and Si are referred to as y wt.% and x wt.%, respectively, 0=x=2.0, 0=y=0.3 and y > -0.15x + 0.015ab (wherein when 0.3=Bi<1 wt.%, 1=Bi<2 wt.% and 2=Bi=4 wt.%, a is 0.2, 0.75 and 1, respectively, and when the apparent Zn content is 37 to below 39 wt.% or 39 to below 41 wt.%, b is 1 while when the apparent Zn content is 41 to below 43 wt.% or 43 to 45 wt.%, b is 0.75) together with the balance substantially consisting of Zn and unavoidable impurities.</p> |
