Welding suitability of nickel materials
In addition to the well-known steel and aluminium materials and the copper materials discussed in the last issue, nickel materials also occupy a relatively large space in the field of resistance welding. These have approximately twice the electrical conductivity of steel. However, the thermal conductivity is only slightly higher compared to steel. For resistance welding, a higher current is required for this reason. In addition, a higher electrode force must be selected, as the nickel materials tend to stick to the electrodes.
Just as with the copper materials, short welding times are required. Silver-plated electrodes are often used with nickel materials. The spot welding suitability in general can be described as very good if these boundary conditions are observed. For example, a welding current of approx. 17 kA at 100 ms welding time and an electrode force of 5 kN is recommended for a single-cut joint of 1 mm nickel sheet. Mixed joints with steel are also possible. Likewise, projection and roller seam welding applications can be carried out well.
For flash butt welding of nickel materials, it should be noted that a high welding energy is required, as well as a high upsetting force and a higher upsetting speed than for steel materials.
As always, you can find more information in the DVS leaflets and from your Harms & Wende partner.