BÖHLER FOX CM 9 Kb is a core wire alloyed covered electrode with a basic coating, meant for manual arc welding. After post weld heat treatment the 9Cr-1Mo type deposit has a fully tempered martensitic structure. The manufacturer directs it to tube, plate and forgings made of creep resistant steels of this class in thermal power and petrochemical plants.
The base materials are 1.7386 (X11CrMo9-1), 1.7388 (X7CrMo9-1) and 1.7398 (GX12CrMo10-1). The approval covers long term service up to 600 degrees C. The basic coating keeps the diffusible hydrogen content low, and the metal recovery reaches about 115 percent.
- Classification EN ISO 3580-A: E CrMo9 B 4 2 H5
- Classification EN ISO 3580-B: E6218-9C1M H5
- AWS classification A5.5 / SFA-5.5: E8018-B8 H4
- Coating: basic
- Current: DC+
- Diameters: 2.5 / 3.2 / 4.0 mm
- Lengths: 250 and 350 mm
- Approvals: TÜV (02183), CE
Steel of the 9Cr-1Mo type without vanadium is tempered in a different temperature window than P91, so do not carry parameters over from one procedure to the other. Preheat to the temperature in the data sheet and hold it through the whole welding operation. After the last bead cool the joint in a controlled way and then anneal it. Throw the stubs away early, because an overheated coating gives spatter and a restless arc.
