The Influence of Annealing on the Structure and Hardness of Electrodeposited Chromium

SynopsisElectron-micrographs of chromium conventionally electrodeposited and then annealed at a series of temperatures up to 700°C. are presented. The mean grain diameter obtained after a 1-hour anneal at 700°C. was 7,900 Å; it diminshed steadily with reduction of annealing temperature to 1460 Å for a 1-hour anneal at 450°C. The hardness showed a concomitant change, but this does not necessarily mean that increase of hardness is caused by decrease in grain size; changes during annealing of other factors such as oxide dispersion, stress, preferred orientation and hydrogen content may well cause the changes both in grain size and in hardness.