50 



CR 



Co'p'per and Copper-base Alloys 

 70 



60 



50 



oo 40 



o 30 



20 



10 



500 600 700 800 900 1000 1100 1200 1300 1400 

 Annealing Temp.in Deg.E (I Hr.a+ Temp.) 



Chart 63. — The effect of annealing on the Rockwell hardness, 

 percentage elongation in 2 in., and grain size of low-brass (80-20) 

 strip, previously cold-roUed 4 B. & S. Nos. (37 per cent reduction of 

 area) from a grain size of 0.020 mm. (80.41 % copper) (0.040-in. stock) . 



500 600 700 800 900 1000 1100 1200 1300 1400 

 Annealing Temp, in Deg.E( IHr. a+Temp.) 



Chart 64. — The effect of annealing on the yield strength of low- 

 brass (80-20) strip, previously cold-rolled 4 B. & S. Nos. (37 per cent 

 reduction of area) from a grain size of 0.020 mm. (80.41 % copper) 

 (0.040-in. stock). 



r '^ 



'^ \: 

 C o- 



(J o 



u o 



Si> ~. 



.r? 



D U 

 gj 



30 40 50 60 70 80 90 100 110 



Rockwell Hardness F- /'is" Ball 60 kg. Load 



5 23 40 58 76 

 Rockwell Hardness B- '/is" Ball 100 Kg. Load 



63 68 74 60 85 

 Rockwell Hardness 15-T /is Ball 15 Kg. Load 



19 31 43 55 67 

 Rockwell Hardness 30-T yie Ball 30 Kg. Load 



Chart 65. — This chart can be employed to determine the approxi- 

 mate tensile strength and percentage elongation of low-brass (80-20) 

 strip (80.41 % copper) when only Rockwell hardness is known. It is 

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

 given limits. 



0.001 0002 0003 0.004 0.005 0.006 



S+rain, Inches per In. 



Chart, 66. — The effect of cold working on the stress-strain charac- 

 teristics of low-brass (80-20) strip (0.040 in. thick) having a ready- 

 to-finish grain size of 0.020 mm. (80.41 % copper) ; 5,000-lb. capacity 

 hydraulic testing machine and Templin automatic extensometer 

 accurate to 0.00001 in. used. 



