168 



Copper and Copper-base Alloys 



TABLE 11 



MANGANESE BRONZE 



Copper, 58.64%; iron, 1.13%; tin, 0.75%; manganese, 0.02%; zinc, balance 



Property 



Rod 



Hard» Soft' 



Forgings 



Cold" 



TensUe strength, p.s.i. (000 omitted) 



Apparent elastic limit, p.s.i. (000 omitted) 



Yield strength, 0.5% extension, p.s.i. (000 omitted) 



Yield strength, 0.2% offset, p.s.i. (000 omitted) 



Yield strength, 0.1% offset, p.s.i. (000 omitted) 



Elongation, % in 2 in 



Reduction of area, % 



Rockwell hardness F, l^i^-m. ball, 60-kg. load 



Rockwell hardness B, Ke-in- ball, 100-kg. load 



BrineU hardness, 10-mm. ball, 500-kg. load 



Modulus of elasticity, p.s.i 



Electrical conductivity,<8« % I.A.C.S., 68°F 



Thermal conductivity,'*" B.t.u. per sq. ft. per ft. per hr. per °F., 68°F. 



Density, lb. per cu. in 



Forging range, °F 



Forging quality 



Type structure 



90 

 65 

 65 

 65 

 55 

 10 

 20 



65 

 22 

 27 

 28 

 24 

 35 

 48 

 93 

 64 

 101 



64-67 

 17-27 

 27-47 

 22-50 

 18-45 

 25-40 

 45-50 

 92-100 

 64-75 

 101-120 



68 

 35 

 35 

 40 

 29 

 40 

 65 

 93 

 64 

 101 



15,000,000 

 23.6 



58 



0,302 



1250-1450 



Excellent 



Two phase, alpha-beta 



■■ Refers to rod cold-drawn 30%; rod under 1 in. in diameter, previously annealed 1100°F. for 1 hr. with a ready-to-finish grain size, 0. 026 i 



' Refers to 1200°F. anneal (1 hr.). 



c Material cold-struck from forged condition. 



100 

 90 

 80 

 70 

 60 

 ■ 50 

 40 

 30 

 20 

 10 

 



50 



5 10 15 20 25 30 35 40 45 

 Percent Reduction in Area 

 Chaet 106. — The effect of cold drawing on the tensile strength and 

 apparent elastic limit of manganese-bronze rod, previously annealed 

 to a grain size^of 0.025 mm. (58.64 % copper, 1.13 % iron, 0.75 % tin, 

 0.02 % manganese, balance zinc) (rod under 1 in. in diameter). 



100 



-o 



o 90 



_j 



^ 80 



o 



o 



= 70 

 o 

 on 



',0 60 

 >., 



£D 50 



<n 



\ 40 

 o 30 



X 



% 20 



QlL 



5 10 15 20 25 30 35 40 45 50 

 Percent Reduction in Area 



Chart 107. — The effect of cold drawing on the Rockwell hardness, 

 percentage elongation in 2 in., and percentage reduction of area of 

 manganese-bronze rod, previously annealed to a grain size of 0.025 mm. 

 (58.64 % copper, 1.13 % iron, 0.75 % tin, 0.02 % manganese, balance 

 zinc) (rod under 1 in. in diameter). 



