| 摘要 |
Disclosed is a pressure-resistant and corrosion-resistant copper alloy which contains 73.0-79.5 mass% of Cu and 2.5-4.0 mass% of Si with the balance made up of Zn and unavoidable impurities. The Cu content expressed as [Cu] mass% and the Si content expressed as [Si] mass% satisfy the following relationship: 62.0 = [Cu] - 3.6 × [Si] = 67.5. In addition, the area ratio of the a phase expressed as a%, the area ratio of the ß phase expressed as ß%, the area ratio of the ? phase expressed as ?%, the area ratio of the ? phase expressed as ?% and the area ratio of the µ phase expressed as µ% satisfy the following relationships: 30 = a = 84; 15 = ? = 68; a + ? = 92; 0.2 = ?/a = 2; ß = 3; µ = 5; ß + µ = 6; 0 = ? = 7; and 0 = ß + µ + ? = 8. |
