Measures to control weld seam with tungsten defect
1. The welding current used is selected strictly according to the type and diameter of the tungsten electrode. Cerium tungsten electrode is a good choice in low current welding environment to ensure good arc ignition performance. Lanthanum tungsten electrode is suitable for large welding current (I > 100A) and AC power supply welding. Lanthanum tungsten electrode is not easy to burst under the condition of large temperature difference.
2. The purity of inert protective gas (≥ 99.9%) is strictly controlled, and Ar O _ 2 gas and Ar CO2 gas can not be used in TIG welding.
3. The tungsten protruding length should be controlled during welding. When the tungsten protruding length is generally kept at 5 mm; welding fillet weld, the best tungsten protruding length is 7 × 8 mm.
4. DC positive polarity is selected for DC TIG welding.
5. Select a reasonable gas flow value; the windshield should be used for welding in outdoor wind.
6. Short arc welding is used as much as possible to enhance the protection effect.
7. Use special grinding equipment to grind tungsten electrode; low current welding tungsten electrode grinding small angle and sharp angle; high current welding grinding appropriate large angle, end grinding into a large angle, fillet.
8. Strengthen the basic skills of welder operation, welding, strictly control the distance between tungsten electrode and workpiece, so as not to contact with the workpiece resulting in tungsten clamping.
