BRONZE STEEL, the name originally given to the metal obtained by the process of General Von Uchatins of the Austrian army, which process consists of casting bronze in a chill-mold and forging it cold. In the casting process hardness is increased and this has the effect of placing the interior metal in a state of compression and the exterior in a state of tension, while the metal has almost the strength and elasticity of steel. The circumstances of chief difficulty and importance in the manipula tion of bronze affecting the production of can non and large castings are: (1) The chemical constitution of the alloy as influencing the bal ance of hardness and tenacity; (2) its chemical constitution and other conditions influencing the segregation of the cooling mass when cast into two or more alloys of different and often variable constitutions; (3) the effect of rapid and slow cooling and of the temperature at which the metal is fused and poured; (4) the effect due to repeated fusions and to foreign constituents in minute proportions entering the alloy. In bronze, sufficient hardness must be
secured to resist longest the abrasions of pro jectiles and deflagration of powder;'along with the greatest ultimate tenacity there must be certain rigidity and ductility with ultimate co hesion; hardness and rigidity increase with the proportions of tin, ductility and tenacity with that of the copper, but not in direct ratio; specific gravity increases with copper. The fusibility is greater than copper and less than tin, ultimate cohesion less than that of tough copper but greater than that of tin, ductility greater than tin but less than copper, hardness greater than either. In consequence of the difference in the fusibility of tin and copper the perfection of the alloy depends much on the nature of the furnace and treatment of the melted metal. By these means alone the tenac ity of bronze has been carried as high as 60,000 pounds.