Gas Tungsten Electrode Arc Welding (GTAW)

Gas tungsten electrode arc welding, also known as gas tungsten arc welding (GTAW), is mainly used for casting repair welding, molding constructing and repairing, construction, and copper alloy piping systems constructing and standard weldments welding, allowing welders to precise control weld line and maximize to increase deposited quality. GTAW preferred power type is DC negative (dcen) and also use high-frequency alternating current (achf). The protective gas is usually high purity helium and tungsten electrode is usually to choose sharp-pointed nose. Tungsten electrode extending torch nozzle length should be 1/4 "to 3/8" (6.4 to 9.5mm). Arc length should be maintained at 1/6 "to 3/16" (1.6 to 4.8mm).

carbide Milling Inserts

GTAW preheat recommendations:
1. Mild steel carbon content less than 0.29% does not require preheating;

2. Medium carbon steel carbon content between 0.3% to 0.59% preheating temperature is between 149 ℃ ~ 315 ℃;
3. Low alloy steel does not require preheating;
4. The gray cast iron preheating temperature is between 204 ℃ ~ 315 ℃, slowly cooling;
5. Ductile cast iron and malleable iron preheating temperature is between 149 ℃ ~ 204 ℃ and after welding should employ annealing;
6. The copper-nickel alloy and silicon bronze does not require preheating and the highest level temperature is 93 ℃;
7. Aluminum bronze aluminum content not more than 10% does not require preheating and the highest level temperature is 149 ℃;
8. Manganese bronze protective gas arc welding preheat temperature is 149 ℃ and shielded metal arc welding temperature (SMAW) is 260 ℃;
9. The preheating temperature of copper is 538 ℃.

Welding current recommendations:

GTAW	Welding Wire Diameter	DC Negative	Alternating Current
	1/16”	70-120	70-150
	3/32”	120-160	140-230
	1/8”	170-230	225-320
	5/32”	220-280	175-300
	3/16”	280-330	200-320
Weldment is nickel alloy or ferroalloy to select smaller value; Weldment is bronze alloy to select intermediate values; Weldment is copper to chose large value;