A Study on the Wind Resistance in a Gas Shielded Arc Welding (Part 2)
The Wind Resisting Effect of the Nozzles
1974 Volume 43 Issue 2 Pages 174-179
Details
1974 Volume 43 Issue 2 Pages 174-179
We have made investigation for the improvement of wind resistance in gas shielded arc welding and extend our experiments of the welding nozzles which we mentioned in our previous paper. In the previous paper, the distribution of the shielding gas velocities, variation of the shape of gas jets and the influence of gas flows on the welds were examined.
In the present paper, the relation between the construction of the nozzles and the wind resistance is discussed based on the X-ray photographs of the welds under windy conditions and the CO2 concentration in the shielding gas jets without arc. Moreover the effect of the distance between the nozzle and the base metal is checked.
The welding nozzles classified in 3 types, i.e. A, B and C, are the same as used in the previous paper. The results are summarized below.
(1) It becomes clear that C type nozzle is most effective to the wind resistance followed by A and B in this order. The limit of the wind velocity is assumed to be 6m/sec in A type, 4m/sec in B type and 6.5m/sec in C type nozzle. Especially in C type nozzle, it is proved that the most suitable ratio of flows (the axial [QZ] and the tangential flows [QR]) exist within 2/1-3/1).
(2) The performance of wind resisting nozzle is proved by measuring the concentration of the shielding gas without arc. When the CO2 concentration is found over 80% in the gas jets, we can obtain a fine weld.
(3) It is desirable that the distance between nozzle and base plate be shorter in the same nozzle to increase the wind resistance in gas shielded arc welding.
