| 摘要 |
<p>In a metal gas arc (MGA) welding process using a spray transfer arc and a shielding gas of mainly Ar and optionally He, the consumable wire electrode feed speed is 15-30 m/min., and the shielding gas consists of 16-50 vol.% CO2, 0-5 vol.% O2, optionally 10-40 vol.% He and balance Ar. Preferably, the shielding gas contains (by vol.) 18-40 (preferably 20-40, especially 23-30)% CO2, 15-35 (preferably 20-30)% He and 0.5-4 (preferably 1-3)% O2. The wire electrode is preferably passed at 18-25 m/min. through a contact tube, the contact tube stand-off distance being maintained at 20-35 mm. Preferably, the wire electrode consists of a ferromagnetic material and is a solid wire which preferably contains 0.3-1.3 (preferably 0.7-1.2) wt.% Si and which is copper coated.</p> |
