SAW Welding: 30V / 300A
Heat input at travel speeds 100–300 mm/min (efficiency η=1)
SAW at 30 V and 300 A is a workhorse parameter set used across structural fabrication, pipe welding, and general repair work on carbon and low-alloy steels. At this electrical input the arc transfers enough energy to fuse plate from about 3 mm up to roughly 12 mm in single-pass work, with thicker sections handled in multiple passes following a qualified WPS. The voltage value controls arc length and bead width while the current value governs deposition rate and penetration; together they define a stable operating envelope that experienced welders can read from puddle behavior alone. Always match the wire diameter and shielding gas to the parameter set called out in your Procedure Qualification Record.
SAW (Submerged Arc Welding) uses a continuously fed bare wire electrode submerged under a layer of granular flux, which shields the arc and weld pool. It delivers very high deposition rates and deep penetration, making it suitable for thick plate steel in shipbuilding, pressure vessels, and heavy structural fabrication.
At 30 V and 300 A, the electrical input power is 9000 W. Voltage primarily controls arc length and bead profile — higher voltage widens and flattens the bead — while current drives deposition rate and penetration depth. Exceeding the rated current for a given wire diameter increases the risk of burn-through on thin sections and premature contact-tip wear.
Heat input directly affects the weld metallurgy. Lower heat input preserves heat-sensitive alloys and reduces distortion; higher heat input improves fusion on thick sections but may coarsen grain structure and reduce toughness. Always verify that heat input falls within the Procedure Qualification Record (PQR) limits for the base material. For carbon steel, heat input above 3.5 kJ/mm may require post-weld heat treatment (PWHT) to restore toughness in the heat-affected zone (HAZ).
Welding Specification
| Process | SAW |
| Voltage | 30 V |
| Current | 300 A |
| Process Efficiency | η = 1 |
Heat Input by Travel Speed
| Travel Speed (mm/min) | Heat Input Q (kJ/mm) |
|---|---|
| 100 | 5.4 |
| 150 | 3.6 |
| 200 | 2.7 |
| 250 | 2.16 |
| 300 | 1.8 |
Amperage Range Notes
High-amperage welding (250 A and above) is the range for heavy plate above 10 mm, structural beams, shipbuilding, and pressure vessel fabrication. Preheat requirements kick in on carbon steel above 25 mm or any time the carbon equivalent exceeds about 0.45 — typically 100–200 °C for 4140 or A572 Grade 50 plate. Interpass temperature must be monitored with a tempil stick or contact pyrometer to keep the HAZ inside spec, usually capped around 230 °C for normalized structural steels. Self-shielded FCAW and submerged-arc welding both work comfortably in this range with single-pass deposits in excess of 15 mm leg height.
Typical Use Cases
SAW at 30 V / 300 A is suited to general-purpose carbon steel fabrication in the flat or horizontal position. Verify wire diameter and shielding gas composition against your weld procedure specification (WPS) before production runs.
Setup Checklist
Confirm wire feed speed matches the target current range. Set gas flow rate to 15–25 CFH for solid wire GMAW, or follow the flux manufacturer's instructions for FCAW. Inspect contact tips and liners for wear before welding. Preheat thick sections (> 25 mm) to reduce hydrogen cracking risk.