Abstract
The effects of non-voltage load on the starting condition of arching in high pressure atmosphere (up to 3 MPa) of argon and helium were investigated. And the effects of an high pressure atmosphere (up to 3 MPa) on arc-voltage and bead formation were also investigated.
The results are as follows:
(1) The critical distance of arc starting between the electrode and the work decreased with increasing of the ambient helium pressure.
(2) The ambient pressure affected the critical distance of arc starting much more in argon atmosphere than in helium.
(3) No-load voltage at arc starting was constant in helium atmosphere between 0.1 MPa and 3 MPa pressure.
(4) The arc voltage in helium atmosphere was higher than that in argon. And it was affected markedly by the ambient pressure.
(5) The shape of welding arc in helium atmosphere was affected remarkably by the ambient pressure in comparison with that in argon.
(6) The erosion of the electrode in helium atmosphere became larger above the ambient pressure of 0.5 MPa.
(7) Good weld can be formed even in helium atmosphere of 3 MPa.
