| 摘要 |
Disclosed is a brass which contains no lead (Pb), and which is excellent in cutting properties, castability, mechanical properties and others. Specifically disclosed is a brass comprising Cu at a content of 55 to 75 wt% (inclusive), Bi at a content of 0.3 to 4.0 wt% (inclusive), and B and Si at such contents that, when the contents of B and Si are represented by y wt% and x wt%, respectively, then y and x fulfill the relationship represented by the following formulae: 0=x=2.0, 0=y=0.3 and y>-0.15x+0.015ab [wherein a is a numeral number of 0.2, 0.85 or 1 when the content of Bi falls within the following range: 0.3=Bi<0.75 wt%, 0.75=Bi<1.5 wt% or 1.5=Bi=4.0 wt%, respectively; and b is a numeral number of 1 when the apparent Zn content is not less than 37 wt% and less than 41 wt%, and a numeral number of 0.75 when the apparent Zn content is 41 to 45 wt% (inclusive)], with the remainder being substantially Zn and unavoidable impurities. The brass has excellent castability, cutting properties, mechanical properties and others. |
