108 
Table E. 
Effect of Hydrochloric Acid on Unannealed Charcoal Iron Wire. 
Description. 
Diame- 
ter. 
inch. 
Ulti- 
mate 
Elonga- 
tion. 
Decrease 
in 
ditto. 
Break- 
ing 
Strain. 
Break- 
ing 
Strain 
per sq. 
inch. 
De- 
crease 
in 
ditto. 
No. of 
tests 
ofwh. 
result 
is a 
mean 
Charcoal iron before 
immersion in acid... 
•046'' 
1% 
lbs. 
134 
lbs. 
80,240 
lbs. 
6 
Ditto after immersion 
in acid for 5 hours... 
•045" 
1-83% 
110-6 
68,616 
6 
Last piece after 7 
days on hot plate... 
•045" 
3-00% 
—2-0% 
94-6 
59,700 
30,540 
6 
Charcoal iron after 
immersion in hy- 
drochloric acid for 
5| hrs., then washed 
and dried in air 6 
hours and again im- 
mersed 5hrs. in acid 
•045" 
1% 
86- 
53,320 
6 
Same piece as last 
heated for 7 days 
on hot plate 
•045" 
5-3% 
—4-3% 
90-6 
56,172 
34,068 
6 
All the above 30 tests were made from one coil. 
Average permanent decrease in B. strain after 
prolonged immersion=32,3041bs. per sq. in, 
„ „ increase in elongation „ =r3*15 per cent. 
Table F. 
Effect of Hydrochloric Acid on Unannealed Mild Steel. 
Description, 
Diame- 
ter. 
inch. 
Ulti- 
mate 
Elonga- 
tion. 
Decrease 
in 
ditto. 
Break- 
ing 
Strain. 
Break- 
ing 
Strain 
per sq. 
inch. 
De- 
crease 
in 
ditto. 
No. of 
tests 
ofwh. 
result 
is a 
mean 
Mild steel before im- 
mersion in acid 
•0905" 
1-66% 
lbs. 
656-3 
lbs. 
102024 
lbs. 
6 
Ditto after immersion 
in dilute acid 5 hrs.. 
•0893" 
2-8% 
—1-14 
613-3 
97979 
-1-4045 
6 
Last piece heated in 
hot room 12 hours 
to a temperature of 
40— 120°C 
•0893" 
2-16% 
-•5% ■ 
671-6 
107295 
—5271 
6 
Last piece heated 7 
days in same hot 
chamber 
•0893" 
3-42% 
—1*76% 
701- 
111992 
-1-9968 
6 
Decrease of Breaking strain on immersion=:4,0451bs. per sq. in. 
Increase of Elongation „ „ =:1-14 per cent. 
Each result is the mean of 6 tests on different coils. 
