Abstract
The effects of various impurities on the internal stress of iron deposits were investigated. The Brenner-Senderoff contractometer was used to measure internal stresses in all determinations.
The results obtained were summarized as follows
1) The curve of manganese represented that the stress was decreased with the concentration in the early stage, but it was increased when the concentration was over 0.5g/l.
2) Nickel linearly increased the stress. The deposit produced by the addition of nickel was brighter than the normal deposit. It was difficult to peel the deposit from the helix with hydrochloric acid, which indicated the possibility of co-deposition of nickel with iron.
3) Chromium and copper had little effects on the stress in the range of concentration studied. The deposit gradually became darker with the increase in the concentration of the impurity.
4) Zinc and tin(II) linearly increased the stress at a high rate. The structure gradually became finer with the increase in the concentration of addition agent.
5) Boric acid and urea decreased the stress. Whereas, sulfates increased the stress.
6) Chlorides had abilities of increasing stress. The addition of ferrous chloride increased the stress in proportion to its concentration.
