May 12, 2020 - ESAB Welding & Cutting Products, Annapolis Junction, Maryland, has globally introduced Cryo-Shield Ni9, a Ni Cr Mo alloy flux cored wire used for all-position welding of 9 percent Ni steel LNG fuel and storage tanks with 100 percent CO2 shielding gas. This modified 625-type wire offers excellent crack resistance and is superior to conventional NiCrMo-3 wires. Mechanical properties are similar to Hastelloy ENiMo-13 flux cored wires but at lower purchase price because of its modified formula. Further, because it uses 100 percent CO2 shielding gas instead of an argon blend, it lowers operating cost. The wire carries approvals from the ABS, BV, DNV GL, KR, LR and CCS classification societies.
“We developed Cyro-Shield Ni9 in response to ship propulsion systems shifting from heavy fuel oil to LNG fuel to reduce oxide emissions,” says Neil Farrow, Global Product Manager – Cored Wires, ESAB. “This wire also meets the needs of LNG storage tank fabricators and other 9 percent Ni steel applications. In benchmark tests against leading 625-alloy wires, Cryo-Shield Ni9 provided superior crack-resistance tolerance, which is especially critical for root welding. Customer field tests with 100 percent CO2 shielding gas also confirmed better tolerance to porosity formation, wet-out for a flatter bead crown and slag release compared to conventional 625-alloy wires. In addition, the slag system supports all-position welding, including over-head.”
ESAB offers Cryo-Shield Ni9 in 1.2 mm diameter and packaged on 300 mm wire baskets or plastic spools; vacuum-seal foil packaging prevents moisture absorption. Typical as-welded mechanical properties are a yield strength of 440 MPa, tensile strength of 730 MPa, elongation of 44 percent and an impact value of 65 J at -196 oC.
