Miller Maxstar 140, Руководство пользователя

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OM-2224 Page 30
SECTION 7 – SELECTING AND PREPARING
TUNGSTEN ELECTRODE
gtaw 7/97
For additional information, see your distributor for a handbook on the Gas
Tungsten Arc Welding (GTAW) process. Wear clean gloves to prevent
contamination of tungsten electrode.
NOTE
7-1. Selecting Tungsten Electrode
Amperage Range - Gas Type
♦
- Polarity
Electrode Diameter DC – Argon – Electrode Negative/Straight
Polarity
DC – Argon – Electrode Positive/Reverse
Polarity
2% Thorium Alloyed Tungsten (Red
Band)
.010” Up to 25 *
.020” 15-40 *
.040” 25-85 *
1/16” 50-160 10-20
3/32” 135-235 15-30
1/8” 250-400 25-40
5/32” 400-500 40-55
3/16” 500-750 55-80
1/4” 750-1000 80-125
♦
Typical argon shielding gas flow rates are 15 to 35 cfh (cubic feet per hour) – 7 to 16.5 lpm (liters per minute).
*Not Recommended.
The figures listed are intended as a guide and are a composite of recommendations from American Welding Society (AWS) and electrode
manufacturers.
7-2. Safety Information About Tungsten
Ref. S-0161
Y
Grinding the tungsten elec-
trode produces dust and fly-
ing sparks which can cause
injury and start fires. Use lo-
cal exhaust (forced ventila-
tion) at the grinder or wear
an approved respirator.
Read MSDS for safety infor-
mation. Consider using
tungsten containing ceria,
lanthana, or yttria instead of
thoria. Grinding dust from
thoriated electrodes con-
tains low-level radioactive
material. Properly dispose
of grinder dust in an envi-
ronmentally safe way. Wear
proper face, hand, and body
protection. Keep flam-
mables away.
1 Pointed Tungsten Electrode
2 Tungsten Electrode With
Balled End
2
1