Pré-aquecimento de A709 Gr.36 para SMAW (non-low-hydrogen) — 1-1/2" to 2-1/2"

SMAW (Non-Low-Hydrogen)

Non-low-hydrogen SMAW (E6010/E6011) uses cellulosic electrodes with higher hydrogen potential, assigned to Category A in Table 5.11.

For common structural shapes and plate, non-low-hydrogen SMAW with E6010 or E6011 excels at root passes on open-root groove welds where burn-through control matters. Vertical-up technique with a slight weave keeps the puddle manageable. Rod consumption runs about 10-12 electrodes per pound of weld metal deposited. Electrode stubs should be no shorter than 2 inches to maintain adequate arc length control.

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 que Este Pré-aquecimento para A709 Gr.36 com SMAW

Bridge-specific 36 ksi grade with CVN testing for highway construction. At this thickness, SMAW with non-low-hydrogen electrodes places the joint in Category A of Table 5.11. The minimum preheat of 225°F compensates for the higher diffusible hydrogen from cellulosic electrode coatings. The thicker the material, the longer hydrogen takes to escape the heat-affected zone, which is why preheat rises with thickness even for this common grade.

Aplicações 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 que o Pré-aquecimento Importa em 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.

Outros Aços com SMAW (non-low-hydrogen) em 1-1/2" to 2-1/2"

A709 Gr.36 com SMAW (non-low-hydrogen)

Experimente Diferentes Combinações

Use a calculadora interativa de pré-aquecimento para consultar qualquer combinação de aço, processo e espessura da D1.1:2025 Tabela 5.11.

Guias de Soldagem de A709 Gr.36