1951 Volume 20 Issue 9-10 Pages 286-293
The authors earlier reported in Part I that the components of arc atmosphere produced during metallic arc welding would be CO, CO2, H2 and H2O and their composition would depend upon water gas reaction at high temperature.
In this paper, the components of exact arc atmosphere directly around the arc during welding using various fluxes of electrodes were studied.
Electrodes used contained cellulose percentages varying 0, 4, 8, 10, 13, 15, 17, 20, 23 and 25, in addition to the base mixture of Ilmenite, Kaolin, FeO, MnO2, SiO2, Fe-Mn and Al2O3.
Five well-known types of electrodes generally used in Japan, two slag shielded types, two medium types and one gas shielded types were also employed.
Arc was started in 1-3mm Hg vacuum welding tube, using Akazaki welding process. Gases were collected in two reservoirs up to about 1.2 atm and then they were analized. Welded deposits and slags were also analized.
The important conclusions obtained in this study are as follows:
1. The components of arc atmosphere obtained in metallic arc welding were CO, C02, H2 and H20 and their compositions depended upon water gas reaction at high temperature (1200°C-1700°C).
2. The greater the cellulose percentage contained in. electrode flux, the more reducing gas in arc at-mosphere was formed.
3. Hydrogen absorbed in molten steel from atmosphere at 1550°C, 1600°C and 1700°C were calcu-lated with application of Sievelt's law and Chipman's data, and of Christensen's formula which combines partial pressures of hydrogen in atmosphere and FeO content in slags.