A Study of the Heat Treatment, Microstructure and Hardness of 60 :40 Brass

WHEN 60:40 brass is heated to 825° C., given a drastic quench to obtain the beta solid solution, and reheated, various changes take place in the structure. Reheating at 200° C. causes a fine, granular, sorbitic structure to appear which has been considered alpha solid solution. These particles coalesce at higher temperatures of reheating, and at 470° C., the alpha forms twins. A further study of these transformations was considered worth investigating. EXPERIMENTAL WORK The object of the experimental work was to study the effect of mechanical work on rolled 60:40 brass, quenched and reheated, and the mechanism of twinning in the alpha reeds of a furnace-cooled specimen. It was desired to determine the effect of mechanical work on the transformations taking place on reheating the quenched material, both at 200 and at 470° C. A study of the nature of the structure resulting from the breakdown of the beta at 200° C. and a study of the mechanism of twinning above 470° C. were considered problems for investigation. The question of the twinning of the alpha reeds was also an important phase of the work. With high-power magnifications, there was hope of following these processes.