C67300

American “manganese bronze” (actually a manganese-containing brass). Corrosion-resistant, high-tensile alloy with good wear characteristics. The actual sample contains 62% Cu, 34% Zn, 2.4% Mn, 1.3% Si and 0.5% Pb. Alpha+beta microstructure with predominating alpha phase. The small blueish precipitations are probably Mn5Si3. The average hardness is 120 HV0.3.