BÖHLER FOX C 9 MV is a basic coated stick electrode whose 9Cr-1Mo-VNb type deposit has a martensitic structure and works in the tempered condition. The manufacturer directs it to joints in creep resistant steels and cast steels of the same class in turbine and power plant construction and in the chemical industry. The material is approved for long term service up to 650 degrees C.
The base grades are 1.4903 (X10CrMoVNb9-1), 1.4955 (GX12CrMoVNbN9-1) and 10Cr9. A very low content of trace elements gives a Bruscato factor below 15, and the limited sum of manganese and nickel, below 1.2 percent by weight, keeps the Ac1 temperature above 780 degrees C. The basic coating holds the level of diffusible hydrogen in the weld low.
- Classification EN ISO 3580-A: E CrMo91 B 4 2 H5
- Classification EN ISO 3580-B: E6215-9C1MV H5
- AWS classification A5.5 / SFA-5.5: E9015-B91 H4
- Coating: basic
- Current: DC+
- Diameters: 2.5 / 3.2 / 4.0 / 5.0 mm
- Lengths: 250, 350 and 450 mm
- Approvals: TÜV (06762), CE
P91 steel needs preheating and an interpass temperature held in the window given in the procedure, and tempering below Ac1 after welding. Before the joint goes into the furnace cool it to the temperature in the instruction, so that the martensitic transformation can run through the whole section. Do not exceed the upper tempering temperature, because above Ac1 the structure re-forms from scratch and the tests will fail. Bake the electrodes and carry them in a quiver, hydrogen is the main enemy here.
