|
 The
place where electrodes are stored should have relative humidity
below 50% and normal room temp say 30-350C these are ideal
conditions. It is also necessary that electrodes are stored in a
separate area where oil grease and other similar hazardous items
are not stored.
Higher humidity results in absorption of moisture by electrode
coverings. This mositure is the source for hydrogen. As we all
know hydrogen can have adverse effects on weldments. For this
reason proper storage, handling and conditioning of electrodes is
necessary. AWS/A 5.1 recommends the following storage conditions.
|
S.
NO |
AWS Class |
Temp |
Relative Humidity |
|
i) |
E6010 |
Ambient |
. . . . |
|
ii) |
E6012, E6013,E7016, E7018
etc |
300C +100C |
Max 50% |
Electrode manufacturers provide a certain degree of moisture
resistant packing by using polythene bags. Number of bags used per
packet vary from 1 to 3 depending upon the type of covering and
the permissible limit of moisture content in the flux coating.
Coating moisture content requirements have been specified in AWS/A5.1
& 5.5 which are reproduced here.
|
AWS Class
(As per AWS/A 5.1 & 5.5) |
COATING MOISTURE
Maximum percentage (after reconditioning) |
|
E 7016. X
E 7018. X |
0.40 |
|
E 8016. X
E 8018. X
E 9018. X |
0.20 |
|
E 10018. X
E 11018. X |
0.15 |
Since the possibility of mositure pickup in transportation and
storage can not be totally eliminated, there is a need for
redrying and rebaking of electrodes before use.
Top
|
Conventional
