Thermanit 30/40 EW is a nickel base covered electrode of the E Ni 8025 type, that is NiCr29Fe26Mo. The manufacturer intended it for joining and surfacing on fully austenitic steels and cast steels containing molybdenum and copper, stabilized and unstabilized, and for joining those materials to unalloyed and low alloy steels.
The base grades are 1.4465 (X1CrNiMoN25-25-2), 1.4563 (X1NiCrMoCu31-27-4) and 1.4577 (X5CrNiMoTi25-25). The maximum service temperature is 450 degrees C. The corrosion resistance is good, especially in reducing environments, and in terms of hot cracking and corrosion resistance the material comes out ahead of the fully austenitic 20 25 5 Cu L / 385 and 25 22 2 N L / 310 (mod.) filler metals. The electrode runs on alternating current and on DC with the electrode positive.
- Classification EN ISO 14172: E NiZ (NiCr29Fe26Mo)
- Typ: E Ni 8025
- Current: AC/DC+
- Diameters: 3.2 / 4.0 mm
- Lengths: 350 mm
- Approvals: TÜV (04587.)
Nickel alloys are welded colder than steel, so keep the current low, the arc short and the beads narrow, without weaving. The pool is thick and does not spread by itself, so shape the weld by guiding the electrode rather than by raising the current. On joints to unalloyed steel lay a buffer layer on the carbon steel side first. Clean the surface after every layer, because slag from nickel alloys can stay at the groove faces.
