| 摘要 |
<p>Titanium tubes are welded from rolled sheet under an inert gas shield. The equipment comprises a table with a lengthways slot. A carriage straddles the slot forming a gas holding enclosure. It also carries the welding torch, its nozzle close to the slot. A longitudinal support holds the rolled sheet against the underside of the table. The edges to be welded are aligned with the slot. The shielding gas, e.g. argon, is piped to the hollow centre of the support and passes into a groove below the joint. Two lips, fixed to the underside of the table, pinch the sheet against the edges of the groove, to prevent escape of gas. This type of welding is frequently carried out in an evacuated chamber, to which argon gas is introduced. For long lengths the equipment described is more economical, and uses less gas.</p> |
