BÖHLER FOX EV 50 is a basic coated electrode of the E7018-1 H4R type, developed for high quality joints in steel structures, boilers, tanks, vehicles, ships and machinery. The manufacturer also recommends it for buffer layers when surfacing high carbon steels and for offshore structures, for which a CTOD test was made at -10 degrees C. The material is qualified for sour gas after the HIC test to NACE TM-02-84, and SSC test values are available too.
The base steels cover S235JR to S355JR, S235JO to S355JO, S235J2 to S355J2, S275N to S420N as well as S275M to S420M and S275ML to S420ML. The deposit combines high strength with impact energy held down to -50 degrees C. The coating is moisture resistant and the diffusible hydrogen stays below 4 ml per 100 g of weld metal. The electrode copes with steels of poorer metallurgical cleanliness and raised carbon content, and the metal recovery reaches about 110 percent.
- Classification EN ISO 2560-A: E 42 5 B 4 2 H5
- Classification EN ISO 2560-B: E4918-1 A U H5
- AWS classification A5.1 / SFA-5.1: E7018-1 H4R
- Coating: basic
- Current: DC+
- Diameters: 2.0 / 2.5 / 3.2 / 4.0 / 5.0 / 6.0 mm
- Lengths: 300, 350 and 450 mm
- Approvals: TÜV (00426), DB (10.014.02), ABS, BV, DNV, LR, RINA, CWB (diameters 3.2 to 6.0 mm), CE
When surfacing high carbon steel, start with a buffer layer of this electrode and lay the hard alloy on top of it. Dry the electrodes to the data sheet and carry them in a quiver if the weld has to meet hydrogen requirements. Weld with a short arc and minimal weaving, on DC with the electrode positive. On heavier parts with raised carbon, set a preheat, because a low hydrogen level alone is not enough against cold cracking.
