ESAB Adds H4R Classification To OK 48.08 7018-G MMA Electrode For Demanding High Strength Weld Applications
February 8, 2022
ESAB has improved its OK 48.08 MMA electrode to a H4R classification — SFA/AWS A5.5 E7018-G H4R — to meet low hydrogen and moisture resistant requirements. The electrode is specifically designed to weld carbon steels, carbon manganese steels and fine grained carbon manganese steels with elevated yield strength. It is ideally suited for construction, offshore and fabrication demanding an all-position electrode with good mechanical properties at low temperature.
“This electrode is really suited for complicated welds in areas with hard to access bevels and shapes,” says Jean-Philippe Ernoult, Global Product Manager Non- and Low-Alloyed Electrodes, ESAB. “By adding the H4R classification we made this, already exceptional electrode even better. It passes all our post-weld heat treatment testing for high strength pressure vessel type applications and is offered in diameters from 5.0 mm down to 2.0 mm, which are hard to find in this category of electrodes.”
ESAB’s improved OK 48.08 offers the same efficiency, mechanical properties and superior weldability in a modern formulation engineered to decrease moisture pick-up in high humidity conditions. Resistance to moisture absorption helps prevent hydrogen cracking and aids in elimination of porosity, especially critical in offshore applications. It uses AC or DC+(-) polarity.
OK 48.08 does not require requalification. It continues to provide mechanical strength with metal alloyed from normal to low alloyed 0.9% Ni steels and fulfills the requirements of impact toughness at -50 degrees C. OK 48.08 has a yield strength of 540 MPa, a tensile strength of 630 MPa and provides the same results with varying heat inputs in any weld position. Its unique formulation makes it possible to achieve the balance in strength and toughness, but also provide a greater resistance to cracking.
“This electrode provides very high deposition rates, with good arc characteristics that results in smooth finished welds with limited spatter,” continues Ernoult. “For demanding applications requiring strict customer specifications, this electrode’s formulation is a superior choice.”
Its low moisture absorprtion coating yields diffusible hydrogen less than 4ml per 100g of weld metal and can be used straight out of the VacPac package without the need to re-bake or store them temporarily in holding ovens or quivers to meet low-hydrogen requirements. Designed for moisture resistances, R electrodes have less than 0.4 percent moisture absorption after 9 hours of exposure at 27 oC and 80 percent relative humidity. OK 48.08 is HIC test compliant as per NACE TM0284, SSC test compliant as per NACE TM0177 and carries approvals from: ABS; CE EN; DB; DNV-GL; LR; NAKS/HAKC; RS; VdTUV.
OK 48.08 electrodes come in VacPac™ packaging, which feature a laminated, multi-layer aluminium foil that is hermetically sealed. Protected by a cardboard outer box, they do not require special warehouse conditions. Provided they are handled with care and the foil is not damaged, upon opening, fresh and dry electrodes are guaranteed.
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OK 48.08 all position AC/DC electrode to a H4R classification — SFA/AWS A5.5 E7018-G H4R — to meet H4R low hydrogen and moisture resistant requirements. The electrode is specifically designed to weld carbon steels, carbon manganese steels and fine grained carbon manganese steels with elevated yield strength.