Crack-Resistant NiCrMo Wire for Welding LNG Fuel, Storage Tanks
ESAB’s Cryo-Shield Ni9 flux cored wire is a modified 625-type wire that’s approved by ABS, BV, DNV GL, KR, LR and CCS. Not only is it offered at a lower-than-expected price point, the wire saves on operating costs.
Posted: May 11, 2020
Cryo-Shield Ni9 from ESAB Welding & Cutting Products (Annapolis Junction, MD), is a NiCrMo alloy flux cored wire used for all-position welding of 9% Ni steel LNG fuel and storage tanks with 100% CO2 shielding gas. This modified 625-type wire offers crack resistance and performs better than conventional NiCrMo-3 wires.
Its mechanical properties are similar to Hastelloy ENiMo-13 flux cored wires, but it’s offered at lower purchase price because of its modified formula. In addition, because it uses 100% CO2 shielding gas instead of an argon blend, users will experience a lower operating cost.
The wire carries approvals from the ABS, BV, DNV GL, KR, LR and CCS classification societies.
“We developed Cryo-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% 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% 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% and an impact value of 65 J at -196 oC.
The company also offers a full portfolio of filler metal and equipment for LNG applications.