ESAB Welding & Cutting Products has introduced Shield-Bright NiCrMo-3, a 625-type electrode for manual and automatic flux cored wide-weave welding of 9% nickel steel in the vertical-up (3G) position and using 75% argon/25% CO2 shielding gas.
“We specifically developed Shield-Bright NiCrMo-3 for a U.S. LNG tank fabricator that had shifted from a 1/8 in. (3mm) vs. 5/32 in. (4 mm) root gap using a ceramic backer,” says David Hamilton, Director of Sales, Stoody, an ESAB brand. “Wider gaps are challenging for high-nickel wires because the puddle tends to be sluggish and have a high crown, but Shield-Bright NiCrMo-3 creates an extremely flat bead profile with excellent tie-in at the toes of the weld. It almost runs like mild steel wire, reducing concerns related to hot cracking susceptibility and stress concentrations.”
The wire is classified as AWS A5.34/5.34M:2018 ENiCrMo3T1-4 wire and has a tensile strength >100 ksi (690 MPa) and a Charpy impact toughness of >52 ft lb. (70 J) at -320oF (-196oC). Shield-Bright NiCrMo-3, delivers mechanical properties that exceed customer requirements because ESAB carefully controls weld metal composition.
During development, ESAB engineers used a weld data analysis system to prove that the wire welds with excellent arc stability and amperage control. Lab tests in the 3G position showed a deposition rate of 5.25 lbs/hr (2.4 kg/hr) using a 0.045-in. (1.2 mm) wire. The slag released easily to reduce risk of slag inclusions and lower-post weld cleaning time and costs.
Family of LNG Filler Metals
Last year, ESAB introduced Cryo-Shield Ni9, 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 excellent crack resistance and is superior to conventional NiCrMo-3 wires. Mechanical properties are similar to Hastelloy ENiMo-13 flux cored wires. 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.
“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% 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.”
Further, because it uses 100% 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.
ESAB offers Shield-Bright NiCrMo-3 and Cryo-Shield Ni9 in 0.045 in. diameter and packaged on 12-in. wire baskets or plastic spools; vacuum-seal foil packaging prevents moisture absorption. To view ESAB’s full portfolio of filler metal and equipment for LNG applications, visit esab.com/lng to view additional product information and success stories.
At ESAB, we exist to shape the future of welding and cutting. We connect fabricators with the widest range of products under our industry-leading brand portfolio with the latest technologies to solve virtually any industry challenge — then we back it up with our knowledge, experience and passion to help them be more productive than ever before. To learn more, visit esab.com.