Volume 13, Issue 5 (September 1985)
Creep Behavior of Copper and Copper Alloys As Design Criteria in Pressure Vessel Manufacture
Six materials, copper and copper alloys, have been subjected to long-term creep tests (30 000 h) per DIN 50 118 at a range of 100 to 250°C, except for aluminum bronze which was tested from 150 to 300°C. The following annealed materials were tested: SF-Cu (DIN 1787)—equivalent to C 12200, Phosphorus Deoxidized Copper, high residual Phosphorus (Cu-DHP); CuZn39Pb0.5 (DIN 17 660)—equivalent to C 33500, low-leaded brass; CuZn20Al2 (DIN 17 660)—equivalent to C 68700, aluminum-brass, arsenical; CuZn28Sn1 (DIN 17 660)—equivalent to C 44300, Admiralty brass, arsenical; CuZn38SnAl (DIN 17 660), improved Muntz-metal, 60%, not standardized in the United States; and CuAl10Ni5Fe4 (DIN 17 665)—similar to C 62730 or C 63000, nickel-aluminum-bronze. The test conditions and the metallurgical history of the materials are described. The minimum value of the 1% creep strain and the average value of creep strength, both temperature and duration dependent, as well as the stress for minimum creep rates of 1% for a given time are also shown. The design criteria for pressure vessels are discussed.