BÖHLER FOX C 9 MVW is a core wire alloyed covered electrode with a basic coating for shielded metal arc welding. The 9Cr-1Mo-1W-VNb type deposit has a fully tempered martensitic structure after heat treatment. The manufacturer directs it to joints in tube, forgings and castings made of creep resistant steels of the ASTM grade 911 class, also known as E911, used in thermal power plants.
The base materials are 1.4905 (X11CrMoWVNb9-1-1) and 1.4906 (GX12CrMoWVNbN10-1-1). The tungsten addition raises the creep resistance, and the material is approved for long term service up to 650 degrees C. The composition is restricted with respect to trace elements, and the basic coating keeps the level of diffusible hydrogen low.
- Classification EN ISO 3580-A: E ZCrMoWVNb 9 1 1 B 4 2 H5
- Classification EN ISO 3580-B: E6215-G H5
- AWS classification A5.5 / SFA-5.5: E9015-B92 H4 (mod.)
- Coating: basic
- Current: DC+
- Diameters: 3.2 / 4.0 / 5.0 mm
- Lengths: 350 and 450 mm
- Approvals: TÜV (09176.), CE
Run the thermal cycle as with the other 9 percent chromium steels: preheating, a controlled interpass temperature, cooling to the value in the procedure and only then tempering. Without post weld heat treatment the joint has no right to enter service. Lay narrow beads, so that the following passes temper the previous layers. Plan the breaks so that the joint does not cool below the interpass temperature.
