56 



Copper and Copper-hase Alloys 



Room 400 500 600 700 800 900 1000 1100 1200 1300 

 Annealing Temp, in Deg.FflHr at Temp.) 



Ch.\rt 84. — The effect of annealing on the Rockwell hardness and 

 percentage elongation in 2 in. of spring-brass strip, previously cold- 

 rolled 6 B. & S. Nos. (50 per cent reduction of area) from two different 

 grain sizes, 0.015 and 0.095 mm. (74.69 % copper) (0.040-in. stock). 



100 

 90 

 80 



d 

 h 60 



00 



5 50 



o 



I 40 



30 



20 



10 







400 500 600 700 800 900 1000 1100 1200 1300 

 Annealing Temp, in Deg.F.(IHr.at Temp.) 



Chakt 85. — The effect of annealing on the yield strength of spring- 

 brass strip, previously cold-rolled 6 B. & S. Nos. (50 per cent reduction 

 of area) from a grain size of 0.015 mm. (74.69 % copper) (0.040-in. 

 stock). 



110 



100 



400 500 600 700 800 900 1000 1100 1200 1300 

 Annealing Temp.in Deg. F. OHr.at Temp.) 



Chart 86. — The effect of annealing on the yield strength of spring- 

 brass strip, previously cold-rolled 6 B. & S. Nos. (50 per cent reduction 

 of area) from a grain size of 0.095 mm. (74.69 % copper) (0.040-in. 

 stock). 



10 20 30 40 50 60 70 80 90 100 



Pockwell Hardness B '/is" Ball lOOKg.Load 

 57 63 69 74 80 86 91 97 



Rockwell Hardness F /is" Ball 60 Kg. Load 

 61 64 67 71 74 77 80 84 87 1Q 93 



Rockwell Hardness l5-T/i6"Ban ISKg.Load 

 15 22 29 36 43 50 57 64 70 76 82 



Rockwell Hardness 30-T J^ie'Soll 30Kg.Load 



Chart 87. — This chart can be employed to determine the approxi- 

 mate tensile strength and percentage elongation of spring-brass strip 

 (74.69 % copper) when only Rockwell hardness is known. It is 

 accurate for all thicknesses between 0.020 and 0.080 in. within the 

 given limits. 



