alloy percentage of the electrode and base metal

[opendoor]

hello everyone, i am a new guy here.
Two questions,
(1)Regarding alloy percentage of the electrode and base metal,which one should be higher?
(2)What determine the color of the spark test of the ferrous material?

 

[metengr]

(1)Regarding alloy percentage of the electrode and base metal,which one should be higher?

There is no general answer. The alloy in the weld rod can be very close to the principal alloying elements in the base metal. The answer is it is case-by-case specific for selection of weld rod.

(2)What determine the color of the spark test of the ferrous material?

Alloy elements