CZ m [06€ * 
= Figure 2 - Elongation reduc- RET 
i lated t ELE 
ne Ductile iron tion related to | 
; Cog pickling time. per1pher 
2 | . tion, 
9 10 = "8 ar the 
ww Blackheart oT the intel 
Sr Malleable Iron oo 
—~—— CL de— a ———— ; ENE 
0 SE 3 6 18 72 
Pickling Time (log h) 
Table I — Effects of the cathodic charging conditions on the mechanical properties 
of Blackheart Malleable Iron and Ductile Iron. 
POST UTS 3 E ET* 
N 
IRON CHARGING CONDITIONS TREATMENT (pa) | Pa) | (2) | (7) 
319 197 | 13,7 - 
2,5 mA/ cm? - 24h = 295 194 9,3 32 
ey 2,5 mA/cm” - 96h - 287 | 194 | 7,5 | 45 
2,5 mA/em® - 96 h 2000 - 4h 311 | 192 | 14,3 | - 
7,5 mA/em® - 24 h = 203 | 197! 7,6! 45 
7,5 mA/cm” - 24 h 2009C -4h 316 | 206 { 12,2 | - 
446 | 313 | 21,8 
7,5 mA/cm® - 24h 421 | 200 | 11,8 | 46 
7,5 mA/ cm? ~- 24h 2009C - 4 h | 443 298 21,7 - 
7,5 mA/em® ~- 72 h 421 | 288 | 12,5 | 43 
%* ET (embrittlement tendency) = per cent elongation loss. 
Figure 3 - Surface cracks develop-— 
A ment during the tensile 
| . Sn & SS test. Ductile Iron, The clear 
ER &% @- ZZ 75 mA/ cm? — 24 h, sen 
Ga Ga gf § Gi 
5 SS ‘ i 
como 7 + e * @ ? nn + 
® Ce , "ee 
Prakt. Met. Sonderbd. 21 (1990) 
‘ 0.8 
sole 
DI 
12U