SA 516 Gr 70 Welding rod

SA 516 Gr 70 Welding Rod

SA 516 Gr 70 is a carbon steel plate grade under ASME SA-516 for pressure vessels, with a tensile strength of 70-90 ksi (485-620 MPa). Selecting the appropriate welding rod (filler metal) for SA 516 Gr 70 is crucial to ensure weld compatibility, toughness, and compliance with ASME Section IX. Common recommendations include low-hydrogen electrodes for SMAW, solid wires for GMAW, and flux-cored wires for FCAW. This article details suitable welding rods for SA 516 Gr 70, based on AWS classifications, with considerations for preheating, PWHT, and comparisons to related grades like ASME SA 516 Gr 65, ASME SA 516 Gr 60, and ASME SA 516 Gr 55. For more details, visit our ASME SA 516 Gr 70 steel plate.

Recommended Welding Rods for SA 516 Gr 70

SA 516 Gr 70 is P-No. 1, Group 2 material, requiring filler metals with matching or overmatching strength (e.g., AWS A5.1 Class E7018 or A5.18 ER70S-6). The filler must ensure welds meet impact toughness at -46°C (optional) and comply with ASME Section IX. Common welding rods/filler metals include:

SMAW (Shielded Metal Arc Welding)

• E7018: Low-hydrogen electrode (e.g., AWS A5.1 E7018-1 or E7018-H4R), tensile strength 70 ksi, suitable for all positions.
  • Why?: Low hydrogen reduces cracking; meets toughness requirements.
  • Preheating: 149-204°C (300-400°F) for >38 mm thickness.

GMAW (Gas Metal Arc Welding)

• ER70S-6: Solid wire (AWS A5.18 ER70S-6), tensile strength 70 ksi, with 75-80% Ar/20-25% CO2 shielding gas.
  • Why?: Good for mill-scaled surfaces; deoxidizers (Si, Mn) improve weld quality.
  • Preheating: Same as SMAW; used for root/fill passes.

FCAW (Flux-Cored Arc Welding)

• E71T-1C or E71T-8C: Flux-cored wire (AWS A5.20 E71T-1C), tensile strength 70 ksi, for 100% CO2 shielding.
  • Why?: High deposition rate for thick plates; self-shielded options available.
  • Preheating: 149-204°C for >38 mm.

For hybrid welding, combine ER70S-6 (root) with E71T-1C (fill) for better performance.

Chemical Composition of SA 516 Gr 70

The base material composition influences filler selection:

Carbon Equivalent (CEV): ~0.43%, calculated as CEV = C + Mn/6 + (Cr + Mo + V)/5 + (Ni + Cu)/15, guiding filler choice to match or overmatch.

Mechanical Properties and Weld Matching

SA 516 Gr 70 has:

• Yield Strength: ≥260 MPa (38 ksi).
• Tensile Strength: 485-620 MPa (70-90 ksi).
• Impact Toughness: ≥27 J at -46°C (optional).

Filler metals must match or exceed these (e.g., E7018 for tensile strength 70 ksi). For low-temp service, select fillers with matching toughness (e.g., E7018-H4R for low hydrogen).

Welding Procedure for SA 516 Gr 70

• Preheat: 149-204°C (300-400°F) for >38 mm to prevent cracking.
• PWHT: 593-649°C (1100-1200°F) for 1 hour per 25 mm thickness for stress relief.
• Filler Compatibility: Use P-No. 1 Group 1 or 2 fillers; overmatching (e.g., E8018) for high-strength welds.
• Testing: Welds must pass ASME Section IX qualification, including impact testing at -46°C if required.

For hybrid welds, use ER70S-6 root with E71T-1C fill for better toughness.

Comparison with Other SA 516 Grades

Key Difference: SA 516 Gr 70 requires overmatching fillers (e.g., E71T-1C for toughness) more often than lower grades due to higher strength, with similar welding rods but stricter PWHT for thick plates.

Applications and Filler Selection

SA 516 Gr 70 is used in:

• Pressure Vessels: High-pressure boilers with E7018 for all-position welds.
• Offshore Structures: Cold marine use with ER70S-6 for root passes.
• Petrochemical Tanks: E71T-1C for high deposition in thick plates.

For low-temp, use low-hydrogen fillers like E7018-H4R.

Why Choose Gangsteel?

Gangsteel supplies SA 516 Gr 70:

• Inventory: Extensive stock in China.
• Sizes: Thickness 6-200 mm, widths up to 3000 mm.
• Delivery: 7-30 days globally.
• Certifications: ASME SA-516, EN 10204 3.1/3.2, UT testing, ABS/LR/BV/DNV approvals.
• Processing: Cutting, rolling, bending; welding consultations available.

Contact us for ASME SA 516 Gr 70 steel plate.

FAQ

What welding rod for SA 516 Gr 70?E7018 for SMAW (low-hydrogen, 70 ksi tensile), ER70S-6 for GMAW (solid wire for mill scale), or E71T-1C for FCAW (flux-cored for high deposition), with preheating 149-204°C for >38 mm.

What is the best filler for SA 516 Gr 70 low-temp welding?E7018-H4R for low hydrogen and toughness at -46°C, or ER70S-6 with PWHT for pressure vessels, ensuring welds match impact requirements.

How does SA 516 Gr 70 welding differ from ASME SA 516 Gr 65?SA 516 Gr 70 requires overmatching fillers (e.g., E71T-1C) for higher strength (260 MPa yield vs 240 MPa), with similar preheating and PWHT, but stricter impact testing for welds.

What is the preheating for SA 516 Gr 70 welding?Preheating for SA 516 Gr 70 is 149-204°C (300-400°F) for >38 mm thickness to prevent cracking; PWHT at 593-649°C for stress relief.

What welding rod for SA 516 Gr 70 hybrid welding?For hybrid welding, use ER70S-6 for root passes and E71T-1C for fill passes on SA 516 Gr 70, ensuring high deposition and toughness.

What is the impact toughness for SA 516 Gr 70 welds?Welds for SA 516 Gr 70 must match base metal toughness (≥27 J at -46°C), using low-hydrogen fillers like E7018-H4R for low-temp service.