ER70S-2 [ER48S-2] is primarily used for single-pass welding of killed, semi-killed, and rimmed steels, but may be used for some multipass applications. Because of the added deoxidants, these filler metals can be used for welding steels that have a rusty or dirty surface, with a possible sacrifice of weld quality depending on the condition of the surface. ER70S-2 [ER48S-2] filler metals are used extensively to produce high quality, high toughness welds with the GTAW process. These filler metals are also well suited for use in single side, melt through welding without a protective root shielding gas on the backside of the joint. Typical specifications for these steels are ASTM A 36, A285-C, A 515-55, and A 516-70, which have UNS numbers K02600, K02801, K02001, and K02700, respectively.
ER70S-3 [ER48S-3] are intended for welding single-pass and multi-pass welds. Typical base metal specifications are often the same as those for the
ER70S-2 [ER48S-2] classification. Electrodes of the ER70S-3 [ER48S-3] classification are the most widely used of the GMAW electrodes classified under this specification.
ER70S-4 [ER48S-4] are intended for welding steel where conditions require more deoxidation then is provided by the
ER70S-3 [ER48S-3] filler metal. Typical base metal specifications are often the same as those for the
ER70S-2 [ER48S-2] classification. This classification does not require impact setting.
ER70S-6 [ER48S-6] are intended for both single- and multi-pass welding. They are especially suited for sheet metal applications, where smooth weld beads are desired, and structural and plate steels that have moderate amounts of rust or mill scale. These electrodes permit the use of higher current ranges with either CO
2 (
AWS A5.32 Class SG-C) shielding gas or with mixtures of argon and oxygen (
AWS A5.32 Class SG-AC-Y). However, these electrodes do require a higher level of oxidation than the previously described electrodes when using either binary or ternary argon shielding gas mixtures per the
AWS A5.32 specification. Typical base metal specifications are often the same as those for the "
ER70S-2 [ER48S-2] classification.
