Projection welding spot welding deformation is usually one of the two boards out of the bump, and then welding. Overcome the spot nugget offset the shortcomings of the current focus, therefore, projection welding, the thickness of the workpiece can be more than 6:1. Projection welding, the electrode must be with the bumps are pressure fed rapidly decreased, otherwise it will splash due to loss of pressure, it should be convex welder electrode with good mobility. Multi-point projection welding, the Nickel Welding Electrodes is inappropriate, will cause the bump shift phenomenon and lead to lower joint strength. Experiments show that the shift is caused by the current through the electromagnetic force. The actual welding, because the bump is highly inconsistent, the parallelism of upper and lower electrodes, a bit fixed-point move than two moving. In order to prevent bump shift, in addition to conditions to ensure the normal nugget, use a larger electrode pressure, smaller welding current, should also be possible to improve the pressurized system with the mobility. Improve is to reduce the pressure system with the mobility movable part of quality-oriented part of the rolling friction. Welding Electrodes Manufacturer, in order to overcome the pressure between the bump is not balanced, with additional warm-up pulse or rotating electrode approach. Second, the projection welding process parameters
Classification of flux cored wire is more complicated, according to the wire structure, flux cored wire can be divided into two kinds of seamed CO2 Gas Shielded Welding Wireand seamless wire. Seamless wire can be copper, good performance, and low cost, has become the future development direction.
Depending on whether the shielding gas, flux cored gas shielded welding and self-shielded welding wire; flux cored wire core powder ingredients with the electrode the drug skin deep similar containing arc stabilizer, deoxidizer, slagging and alloys, etc., can be divided into (slagging agent) wire of the powder-type "and" metal powder "(no slagging agent) wire; accordance with the basicity of the slag can be based on whether the slagging agents in the flux cored wire inner filler powders can be divided into divided into the titanium type (acidic residue), Chin calcium type (neutral or weak alkaline slag) and calcium type (the alkaline residue) wire.
Generally speaking, of titanium slag Department flux cored wire weld forming beautiful, all-position welding process performance, stable arc, little splash, but poor weld metal toughness and crack resistance. In contrast, calcium flux cored wire weld slag system excellent toughness and crack resistance, but somewhat less weld forming and welding performance. The calcium titanium slag Department from above between the two.
The metal powder type flux cored wire welding performance similar to the Copper Alloy Welding Wireefficiency and better crack resistance than powder type "wire cored mostly metal powder (iron, deoxy, etc.) , also joined the special arc stabilizer, which guarantees the welding slagging, high efficiency, small spatter, stable arc characteristics and weld diffusible hydrogen content, improved crack resistance.
The cross-sectional shape of the flux-cored wire welding performance and metallurgical properties. Simple cross-section "O"-shaped and complex cross-section folded two categories, folded shape can be divided into plum-shaped, T-shaped, E-shaped, and the middle filler wire shaped and so on can be divided according to the cross-sectional shape of the flux cored wire.
Generally speaking, the cross-sectional shape of the flux cored wire is more complicated and more symmetrical, more stable arc, cored metallurgical reaction and protection role more fully. But with the reduction in the wire diameter, and this difference is gradually reduced, and when the wire diameter is less than 2mm, the sectional shape of the impact has been obvious. Currently, small-diameter (≤ 2.0mm) flux-cored wire generally use the "O"-shaped cross-section, large diameter (≥ 2.4mm) flux-cored the use of E-shaped, T-shaped folded form of complex cross-section.