AWS D1.1:2025 · Tabella 5.11 · Categoria B

Preriscaldo di A588 per SAW — up to 3/4"

Temperatura minima di preriscaldo e interpass per A588 saldato con SAW a spessore up to 3/4", secondo AWS D1.1:2025 Tabella 5.11.

Basato su AWS D1.1:2025 Tabella 5.11 — ogni valore tracciato alla clausola.

Temperatura Minima di Preriscaldo e Interpass
32°F / 0°C
Categoria B
Processo SMAW, SAW, GMAW o FCAW basso idrogeno
AWS D1.1:2025 Tabella 5.11, §5.7
Quando la temperatura del metallo base è inferiore a 32°F [0°C], preriscaldare a minimo 70°F [20°C] e mantenere durante la saldatura (Tabella 5.11 nota a).
Strumento di riferimento. Verificare contro l'edizione applicabile e WPS approvata dall'Ingegnere.

SAW (Submerged Arc Welding)

SAW submerges the arc beneath granular flux for highest deposition rates, flat/horizontal only. Category B in Table 5.11.

SAW with F7A2-EM12K wire/flux delivers the highest deposition rates for flat-position fillet welds on building steel. Typical parameters: 500-700 amps, 28-32 volts, 18-30 IPM travel speed. Flux consumption runs approximately equal to wire consumption by weight. Unfused flux recovery and recycling systems are standard in production shops to control consumable costs.

SAW Tips for Common Structural Steels

For A588 weathering steel (50 ksi yield, CE-IIW 0.45–0.52), SAW with weathering-composition wire (EM12K-W or similar) and neutral flux handles girder web-to-flange fillet welds on unpainted bridge fabrication. The higher alloy content of A588 means the SAW heat input on thick flanges is a more critical parameter than on A36 — target 30–55 kJ/in to avoid excessive grain growth in the wide HAZ.

Typical values for reference — always verify against your approved WPS and electrode manufacturer data.

Filler Metal for SAW

Wire: EM12K or EL12 with matching flux (AWS A5.17). Common combo: F7A2-EM12K. Diameter: 3/32" or 7/64". Flux type: active (A) for single-pass, neutral (N) for multi-pass. Voltage: 28-34V. Current: 400-800A depending on joint size. Travel: 12-24 ipm.

Typical values for reference — always verify against your approved WPS and electrode manufacturer data.

A588

ASTM A588 is a weathering steel specification (50 ksi minimum yield, 70 ksi minimum tensile) that forms a protective iron oxide patina when exposed to atmospheric wet-dry cycling. The copper (0.25-0.40%), chromium (0.40-0.65%), and nickel (0.25-0.40%) alloying creates a dense, adherent rust layer that stabilizes after 2-5 years of exposure. Used in unpainted bridges and exposed structural members, it requires low-hydrogen processes (Category B) per Table 5.11 due to its higher alloy content pushing CE-IIW to 0.45-0.52. Weld filler metal must be a matching weathering composition (e.g., E8018-W2) to achieve corrosion-matching at exposed joints. A588 is produced as plate up to 8" thick and is available in structural shapes, though A709 Gr.50W is more commonly specified for bridge applications.

Perché Questo Preriscaldo per A588 con SAW

Weathering steel forming protective patina for unpainted bridge applications. This steel is prequalified only with low-hydrogen processes under Table 5.11. With SAW, the submerged arc process with granular flux produces controlled hydrogen levels, with flux condition being the primary variable. The 32°F minimum preheat balances the steel’s strength level and carbon equivalent against the hydrogen control provided by SAW. Non-low-hydrogen SMAW is not an option for this grade under D1.1 prequalified WPS.

Applicazioni Tipiche di A588

Used in unpainted highway bridge girders, exposed pedestrian bridges, architectural weathering facades, transmission tower legs, rail bridge stringers, and marine navigation light structures. A588 welds must use compatible weathering-type filler metals (e.g., E8018-W2 or ER80S-G) to achieve matching corrosion resistance in the exposed weld face. Girder flange splices and stiffener fillet welds are primary fabrication joints. The distinctive brown-orange patina develops over 2-5 years of atmospheric exposure to form a stable, adherent oxide layer that does not require repainting. In coastal locations with salt spray or in areas where the surface stays wet for extended periods, the protective oxide layer may not form properly, limiting A588 to inland applications with reliable wet-dry cycling. Bolt holes and copes must be deburred to prevent corrosion concentration. Drainage details in the steel design prevent water traps that would undermine the patina formation process.

Perché il Preriscaldo è Importante a up to 3/4"

Thin material sheds heat quickly, allowing hydrogen to escape the HAZ readily — lowest preheat tier in Table 5.11.

Altri Acciai con SAW a up to 3/4"

AcciaioCategoriaPreriscaldo
A36B32°F (0°C)
A633 Gr.EC50°F (10°C)
A709 HPS70WC50°F (10°C)
A710 Gr.AC50°F (10°C)

Prova Diverse Combinazioni

Usa il calcolatore interattivo di preriscaldo per consultare qualsiasi combinazione acciaio, processo e spessore dalla D1.1:2025 Tabella 5.11.

Qual è il preriscaldo minimo per A588 con SAW a up to 3/4"?
Per A588 saldato con SAW a spessore up to 3/4", la temperatura minima di preriscaldo è 32°F (0°C) secondo AWS D1.1:2025 Tabella 5.11, Categoria B.
Quale categoria della Tabella 5.11 si applica a A588 con SAW?
A588 saldato con SAW rientra nella Categoria B di AWS D1.1:2025 Tabella 5.11. Processo SMAW, SAW, GMAW o FCAW basso idrogeno. A spessore up to 3/4", questa categoria richiede un preriscaldo minimo di 32°F (0°C).
A588 necessita di preriscaldo a up to 3/4"?
A spessore up to 3/4" con SAW, il preriscaldo minimo è 32°F (0°C) — effettivamente temperatura ambiente sopra il punto di congelamento. Non è necessario preriscaldo attivo a meno che il metallo base sia sotto i 32°F.

Dati di riferimento D1.1:2025. Non affiliato con AWS.