The Cwpro-nickels 



237 



90 



80 



70 



. 60 

 c 



c^50 



g.40 



5 30 

 o 

 o 

 S 20 



CR 700 800 900 1000 1100 1200 1300 1400 1500 1600 

 Annealing Temp, in Deg.F. (iHr: at Temp.) 



Chart 32. — The effect of annealing on the yield strength of 80-20 

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

 reduction of area) from a grain size of 0.055 mm. (78.18 % copper, 

 20.65 % nickel, 0.51 % manganese) (0.040-in. stock). 



20 



90 



30 40 50 60 70 80 



Rockwell Hardness J^ie Ball B 100 Kg. Load 



74 80 86 91 97 



Rockwell Hardness V\i' Ball F 60 Kg. Load 



71 74 77 80 84 87 



Rockwell Hardness Xie" Ball I5T 15 Kg. Load 



36 43 50 57 64 70 



Rockwell Hardness /le" Ball 30T 30 Kg. Load 



Chart 33. — This chart can be employed to determine the approxi- 

 mate tensile strength and percentage elongation of 80-20 cupro-nickel 

 strip (78.18 % copper, 20.65 % nickel, 0.51 % manganese) when only 

 Rockwell hardness is known. It is accurate for all thicknesses between 

 0.020 and 0.080 in. within the given limits. 



69 



67 



29 



90 



76 



0.002 O004 0.006 0.008 



5+rain^ Inches per In. 

 Chart 34. — The effect of cold rolling on the stress-strain character- 

 istics of 80-20 cupro-nickel strip (0.040 in. thick) having a ready-to- 

 finish grain size of 0.015 mm.; 5,000-lb. capacity hydraulic testing 

 machine and Templin automatic extensometer accurate to 0.00001 in. 

 used. (78.18 % copper, 20.65 %. nickel, 0.51 % manganese.) 



O002 0.004 Q006 0.008 



S+rafn^ Inches per In. 

 Chart 35. — The effect of cold rolling on the stress-strain character- 

 istics of 80-20 cupro-nickel strip (0.040 in. thick) having a ready-to- 

 finish grain size of 0.055 mm.; 5,000-lb. capacity hydraulic testing 

 machine and Templin automatic extensometer accurate to 0.00001 in. 

 used (79.18 % copper, 20.65 % nickel, 0.51 % manganese). 



