Precalentamiento de A709 Gr.36 para SAW — 1-1/2" to 2-1/2"

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.

Why SAW for A709 Gr.36 at 1-1/2" to 2-1/2"

Why SAW for A709 Gr.36 at 1-1/2" to 2-1/2"? SAW delivers 15-40 lb/hr deposition — the highest deposition rate among available processes. Position capability: flat and horizontal only. Suitability: shop only.

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.

A709 Gr.36

ASTM A709 Grade 36 is the bridge-specific equivalent of A36, used exclusively for highway bridge construction under AASHTO LRFD Bridge Design Specifications. With 36 ksi minimum yield, 58-80 ksi tensile, and mandatory Charpy V-notch testing requirements based on AASHTO temperature zone (Zone 1: 70°F, Zone 2: 40°F, Zone 3: 10°F test temperatures), it qualifies for both Category A and Category B preheat in Table 5.11. Chemistry matches A36 (0.26% max carbon) but the CVN requirements add a fracture resistance guarantee absent from plain A36. A709 Gr.36 is primarily used for secondary bridge members — lateral bracing, floor beam stiffeners, diaphragm plates, and bearing components — where Gr.50 strength is not needed but bridge-code CVN compliance is required.

Por qué Este Precalentamiento para A709 Gr.36 con SAW

Bridge-specific 36 ksi grade with CVN testing for highway construction. With low-hydrogen SAW, this combination falls under Category B rather than Category A — the submerged arc process with granular flux produces controlled hydrogen levels, with flux condition being the primary variable. The 150°F minimum preheat is lower than what non-low-hydrogen SMAW would require at the same thickness because SAW significantly reduces the driving force for hydrogen-induced cracking in the heat-affected zone.

Aplicaciones Típicas de A709 Gr.36

Specified exclusively for highway bridge deck plate, floor beams, lateral bracing, secondary framing, bridge railing posts, abutment bearing stiffeners, and diaphragm plates. A709 Gr.36 requires CVN testing per AASHTO zone classification, distinguishing it from plain A36 by guaranteeing fracture resistance at the bridge’s design service temperature. Transverse stiffener fillet welds and floor beam web-to-flange joints are high-frequency fabrication details in bridge shops. The fracture-critical designation on certain bridge members imposes additional NDT requirements (UT in lieu of RT for CJP welds) and welder qualification testing beyond standard D1.5 provisions. Temperature zones (1 through 3) determine the CVN test temperature for the Charpy specimens: Zone 1 at 70°F for moderate climates, Zone 2 at 40°F for cold climates, and Zone 3 at 10°F for severe cold. Mill certifications must show CVN results meeting the specified zone before plate release to the bridge fabricator.

Por qué el Precalentamiento Importa en 1-1/2" to 2-1/2"

Heavy plate with significant restraint and thermal mass — preheat is critical to maintain slow cooling for hydrogen escape.

Otros Aceros con SAW en 1-1/2" to 2-1/2"

A709 Gr.36 con SAW

Prueba Diferentes Combinaciones

Usa la calculadora interactiva de precalentamiento para consultar cualquier combinación de acero, proceso y espesor de D1.1:2025 Tabla 5.11.

Guías de Soldadura de A709 Gr.36