Abstract
In the previous report, the author proposed the value of the deoxidation tendency (R1+1/2R2-A) calculated from the chemical composition of fluxe and proved the relation between its value and the oxygen contents in weld metal. In this report, further, the relation was investigated about several types of electrodes produced experimentally.
The relation between (R1+1/2R2-A) and [O] is different from each other depending on the type of coating, as the basicity of slag is different. In electrodes used Fe-Si as deoxidizer, the relation between (R1+1/2R2-A) and [O] is different from the relation in electrodes used Fe-Mn in the cases of acidic types. The cause of which is presumed as follows: the reaction velocity of Si-deoxidation is slower than that of Mn-deoxidation, and weld metals are solidified before when the reaction rea-ches to equilibrium state. But that relation is not different in the case of basic type, because the reactions of Si-deoxidation and Mn-deoxidation are fast in the case of basic type. In spite of this experiment the consideration about the kind of deoxidizer is not necessary, because Fe-Mn is, only, used in acidic types electrode on the market. Therefore, it is able to presume the oxygen contents in weld metals from the chemical composition of fluxes.
These considerations are based on the experimental values of Km, and Ksi, which shows the distribution of Mn and Si between slag and weld metal, obtained in this experiment. KMn and Ksi in basic type (low hydrogen type) electrodes are different from these in acidic types (the other types) electrodes. In acidic types, Si contents in weld metals depend on the basicity of slags (SiO2 contents in slags), so oxygen contents are lower in the cases of strong acidic slags than nearly neutral slags. Next, KSi in electrodes used Fe-Si are different from the one in electrodes used Fe-Mn in the case of acidic types, but no difference in the case of basic type. After these experiments, it is proved that the slag-metal interactions affect extremely to the deoxidation reactions during welding process.
