A physico-chemical study has been made on the deoxidation in welding using the data described in the Report 1-Report 4, and the following results are obtained.
As the weld slags are not generally saturated with a deoxidation product, the oxygen content in weld metals is affected by not only the composition of the metals, but also the composition of the slags. Thus the following equation was obtained for the oxygen in the metals:
log[%O]=A/n⋅B
L-m/n⋅log [%M]+1/n⋅log (%M
mO
n)-1/n (C-nD)
where, [%O]: the oxygen content in the weld metals
[%M]: the content of an alloying element in the weld metals
(% M
mO
n): the content of the deoxidation product in the weld slags
A⋅B
L+C: the logarithm of an equilibrium index represented by (%M
mO
n)/[%M]
m⋅(%FeO)
nD: the logarithm of an equilibrium index represented by [%O]/(%FeO)
The deoxidation powers of alloying elements on the same condition of slags decrease in the following order: Al, Ti, Si, Mn, V, Cr, W, Mo and Ni.
The deoxidation with silicon is appoximately reached to the equilibrium state, but that with manganese is not so. The oxygen content therefore should be discussed by rather silicon than manganese.
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