Shielding gas and purging techniques during welding Part 3: Welding enclosures and trailing shields

摘要

Traditionally, permanent metal enclosures have been used when welding materials that are sensitive to contamination from atmospheric gases. Such enclosures may be evacuated using vacuum pumps or purged with inert gas. These solutions are expensive, time consuming and occupy a large permanent footprint - clearly quite unsuitable for routine welding applications. A typical steel GTAW vacuum enclosure with a volume of 1 cu m costs in the region of GBP 11,000' and a simple inert gas version about GBP 50002. A high vacuum electron beam welding plant of similar size is likely to cost upwards of GBP 60,0003.