Pré-aquecimento de A106 Gr.B para SMAW (non-low-hydrogen) — up to 3/4"
Temperatura mínima de pré-aquecimento e interpasse para A106 Gr.B soldado com SMAW (non-low-hydrogen) em espessura up to 3/4", conforme AWS D1.1:2025 Tabela 5.11.
Baseado na AWS D1.1:2025 Tabela 5.11 — cada valor rastreado à cláusula.
Processo SMAW não baixo hidrogênio
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.
On pipe joints, non-low-hydrogen SMAW root passes with E6010 use the keyhole technique to ensure complete penetration. Pipe rotation (roll welding) is preferred when practical; fixed-position welding requires 5G or 6G qualified procedures. The cellulosic coating generates significant spatter, so adjacent base metal should be protected with anti-spatter compound.
A106 Gr.B
ASTM A106 Grade B covers seamless carbon steel pipe for high-temperature service up to about 750°F, with 35 ksi minimum yield and 60 ksi minimum tensile strength. Produced in sizes from 1/4" through 30" NPS, it is the standard pipe material for power plants, refineries, and process piping where elevated temperature and pressure coexist. Chemistry limits (0.30% max carbon, 0.29-1.06% manganese) give it a weldability profile that matches common structural grades with Category A and B preheat requirements. A106 is exclusively seamless, which eliminates the ERW seam concern present in A53. Grade C (40 ksi yield) exists but Grade B handles the vast majority of process piping service.
Por que Este Pré-aquecimento para A106 Gr.B com SMAW
Seamless pipe rated for high-temperature service up to 750°F. At this thickness, SMAW with non-low-hydrogen electrodes places the joint in Category A of Table 5.11. The minimum preheat of 32°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 A106 Gr.B
Used in boiler steam headers, refinery piping racks, process plant branch connections, heat exchanger nozzle welds, power plant main steam lines, petrochemical reactor feed piping, and high-temperature manifolds. A106 Gr.B butt welds in process piping require joint preparation to B31.1 (power piping) or B31.3 (process piping) depending on service classification. Socket welds on small-bore A106 drain lines and instrument take-offs are common in utility stations, typically 1/2" to 2" NPS. Typical wall thicknesses range from Schedule 40 (0.237" wall on 2" NPS) to Schedule 160 (0.500" wall on 4" NPS) in critical high-energy service. Weld procedure qualification often includes side bend tests and tensile tests specific to the pipe diameter and wall thickness being joined. Field welds at pipe-to-flange connections and valve set-on joints require portable preheating equipment when wall thickness exceeds 1/2".
Por que o Pré-aquecimento Importa em up to 3/4"
Thin material sheds heat quickly, allowing hydrogen to escape the HAZ readily — lowest preheat tier in Table 5.11.
Por que 32°F para A106 Gr.B?
Um pré-aquecimento mínimo de 32°F (0°C) significa que nenhum pré-aquecimento ativo é necessário acima das condições de congelamento. A Tabela 5.11 Categoria A nesta espessura atribui o mínimo ambiente porque A106 Gr.B com SMAW não baixo hidrogênio possui ductilidade suficiente e equivalente de carbono baixo o bastante para que o risco de trinca por hidrogênio seja mínimo. Conforme a nota de rodapé (a), se a temperatura estiver abaixo de 32°F, pré-aquecer a junta a pelo menos 70°F (20°C) e manter durante a soldagem.
Outros Aços com SMAW (non-low-hydrogen) em up to 3/4"
A106 Gr.B 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 A106 Gr.B
Dados de referência D1.1:2025. Sem afiliação com AWS.