The Relation among the Potential Hydrogen in Electrode Coatings, the Partial Pressure of Hydrogen in Arc Atmosphere and the Disolved Hydrogen in Deposit Metal (Report I)
1952 Volume 21 Issue 5-7 Pages 150-157
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1952 Volume 21 Issue 5-7 Pages 150-157
It is reliable that the potential hydrogen (or available hydrogen) in electrode coating has much influences upon the volume. of the disolved hydrogen in molten steel during metallic arc welding. The relation between them was reported by Sloman and his co-workers who showed linear proportion among them.
However, the disolved hydrogen does not depend directly upon the potential hydrogen in coating, but upon the partial pressure of hydrogen in arc atmosphere generated from coating during welding.
Then, even each potential hydrogen in various coating are contained same volume, the compositions of arc, atomosphere are changed by another components of coatings, and so the volumes of disolved hydrogen in deposit are necessarily changed.
As Reeve already pointed out this problem, he did not study the relation of the three.
We studied the relation between the potential hydrogen in coatings, partial pressure of hodrogen in arc atmosphere and disolved hydrogen in deposit metal using various coated electrodes previously reported.
The results and conclusions obtained are as follows;
(1) The more the potential hydrogen in coatings contained, the more the partial pressure of hydrogen in arc atmosphere and the disolved hydrogen in deposit metal are found, only when same type electrode coatings were used.
(2) When we compared the different types of coatings for example, limestone type to deoxide type of coatings, the partial pressure of hydrogen and volume of disolved hydrogen in deposit collected with grycelin method indicate more with the latter than with the former, while almost same volumes of potential hydrogen in coating contained in both types.
Then, when potential hydrogen in coating changed to the hydrogen component in atmosphere by lime type, it was diluted with CO and CO2 produced from limestone, while deoxide type its dilution was much less than limestone type.
