Physical Properties of Welding Slags

Abstract

In reference to the operating characteristics of arc welding electrodes for mild steel, thermal expansion, thermal conductivity, hardness and microstructure and etc, in solid state ; viscosity and surface tension in liquid state ; and specific gravity and electrical conductivity in both solid and liquid states, of slag produced with five types of covered electrodes, i. e. D4301 (Ilmenite type), D4311 (High cellulose type), D4313 (High titania type), D4316 (Low hydrogen type) and D4320 (High iron oxide type) were determined and the results obtained are as follows ;
Electrode D4301 D4311 D4313 D4316 D4320
Inflection point on cooling curve °C 1124 1153 1218 1157 1138
Viscosity at 1500°C poise c. 10 c. 10 c. 10 c. 7 c. 10
Surface tension at 1500°C dyne/cm 350 to 400
Inflection point appeared on thermal expans 570 530 750 900 650
ion curve °C
Coefficient of linear expansion from 200°C to 8.3 11.5 4.3 9.9 10.0
inflection point X10^-6
Electrical conductivity mho/cm
at 1000°C 3.0 6.7 6.9 2.0 3.0
at 1500°C 5.5 9.8 11.0 5.2 5.6
Thermal conductivity cal/cm/°C/sec
at 100°C 2.5 2.8 2.7 2.9 2.7
at 400°C 3.4 5.8 2.0 8.0 4.4
Specific gravity
at room temp. 3.6 3.6 3.3 3.1 3.9
at 1300°C (liquid) 3.0 2.2 2.2 2.0 3.1
Hardness at room temp. Mob's scale 8 8.5 8.5 6.5 6.5