WEARstick Hydrocav is suitable for wear resistant surfacings with high resistance to cavitation, corrosion, pressure and impact, above all in the construction of water turbines and pumps. Its main field of application is surfacing soft martensitic 13/4 CrNi steels on Kaplan turbine blades. Previously sold as UTP HydroCav.
The classification is E 5-UM-250-CKZT to DIN 8555 and E Z Fe9 to EN 14700. The hardness as welded is about 21 HRC, but thanks to a high work hardening rate the deposit doubles its hardness under impact stress and reaches about 50 HRC. The electrode welds in all positions except vertical down, the arc is stable, the bead builds up evenly and the slag comes off easily.
- Classification DIN 8555: E 5-UM-250-CKZT, EN 14700: E Z Fe9
- Coating: basic
- Current: AC/DC+
- Diameters: 2.5 / 3.2 / 4.0 mm
- Lengths: 250 and 350 mm
- Hardness of deposit: 21 HRC
- Former name: UTP HydroCav
A soft deposit straight after welding is not a fault, the hardness builds in service, so do not spoil the surface with extra heat treatment. Grind cavitation pits out to sound metal and chamfer the edges, then surface in thin beads with little dilution. On 13/4 steels match the preheat and interpass temperature to the grade, and dry the electrodes as the maker specifies.