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.