Study on the Arc Characteristics and Droplet Transfer of the Electrode CJR307 for Low Alloy Heat-resistant Steels

The effects of rutile on the arc characteristics and droplet transfer of the low alloy heat-resistant electrode CJR307 were investigated.Results showed that the eigenvalue of short-circuit time, defined as t₅₀, decreased from 6. 56 ms to 5. 58 ms gradually with the increasing of rutile from 0 to 8% (w). Meanwhile, the spattering was reduced and the stability of arc was improved, indicating remarkable improvement in the weldability of electrode CJR307. With the increasing of rutile, which was used to replace the quartz, the mass fractions of C and Mn in the deposited metal increased, and that of Si decreased. Accordingly, the tensile strength and yield strength presented an increasing trend. However, the impact toughness increased first and then decreased at-20 ℃, and the average value of impact toughness reached 128 J when the addition of rutile reached 4% (w).