136 



Copper and Copper-base Alloys 



m 100 

 ■c 



§ 90 



_i 



J" 80 

 o 

 to 

 u. 70 



D 60 



CO 



"^ 50 



V) 



S 40 

 c 

 ■o 

 ^ ^0 



X 



= 20 



CR 400 500 600 700 800 900 1000 1100 1200 1300 

 Annealing Temp. in Deg.FflHr. at Temp.) 



Chaht 7. — The effect of annealing on the Rockwell hardness and 

 percentage elongation in 2 in. of bearing or weatherstrip bronze strip, 

 previously cold-rolled 6 B. & S. Nos. (50 per cent reduction of area) 

 from two different grain sizes, 0.015 and 0.080 mm. (90.49 % copper, 

 0.48 % tin, balance zinc) (0.040-in. stock). 



80 



70 



ceo 



U0 50 



a40 



30 



-20 



400 500 600 700 800 900 1000 1100 1200 1300 

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



Chart 8. — The effect of annealing on the yield strength of bearing 

 or weatherstrip bronze strip, previously cold-rolled 6 B. & S. Nos. 

 (50 per cent reduction of area) from a grain size of 0.015 mm. (90.49 % 

 copper, 0.48 % tin, balance zinc) (0.040-in. stock). 



110 



100 



90 



80 



70 



60 



50 



400 500 600 700 800 900 1000 1100 1200 1300 

 Annealing Temp in Deg.R flHr at Temp.) 



Chart 9. — The effect of annealing on the yield strength of bearing 

 or weatherstrip bronze strip, previously cold-rolled 6 B. & S. Nos. 

 (50 per cent reduction of area) from a grain size of 0.080 mm. (90.49 % 

 copper, 0.48 % tin, balance zinc (0.040-in. stock). 



20 



10 20 30 40 50 60 70 80 90 100 



Rockwell Hardness B '/i6"Ball lOOKg.Load 

 57 63 69 74 80 86 91 97 - - - 



Rockwell Hardness F '/i6"Ball 60 kg. Load 

 61 64 67 71 74 77 80 84 87 90 93 



Rockwell Hardness 15T '/le'Ball 15 Kg. Load 

 15 22 29 36 43 50 57 64 70 76 82 



i?ockwelI Hardness 30T Me'Ball 30Kg. Load 



Chart 10. — This chart can be employed to determine the approxi- 

 mate tensile strength and percentage elongation of bearing or weather- 

 strip bronze strip (90.49 % copper, 0.48 % tin, balance zinc) when only 

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

 0.020 and 0.080 in. within the given limits. 



