The commonly used welding methods in steel pipe welding, installation, and construction in the petroleum, chemical, natural gas, shipbuilding, and other industries are mainly the following:
① SMAW, due to its slow welding speed and the welding quality being greatly affected by the operator, its application in steel pipe construction has gradually decreased and is only used in places with poor maintenance and accessibility.
② Tungsten inert gas welding (TIG), with good welding quality, high cost, and low efficiency, is generally used in small-diameter steel pipe welding and base welds.
③ Flux-cored CO2 gas shielded welding (FCAW), with high welding efficiency and good weld formation; the cost is slightly higher, and it is not suitable for base weld welding.
④ Solid wire CO2 gas shielded welding (CO2), with high welding efficiency and good weld formation; the lowest cost, due to its relatively low impact toughness, it should be carefully selected when welding important steel pipes, and the welder’s technical requirements are high
⑤ Solid wire mixed gas shielded welding (MAG), with high welding efficiency and good weld formation; low cost, high impact toughness, suitable for important steel pipe welding.
In order to give full play to the advantages of each welding method, several welding methods are often used in construction, such as TIG welding primer + SMAW filling cap welding; TIG welding primer + FCAW filling cap welding; TIG welding primer + CO2MAG solid wire filling cap welding; CO2 solid wire primer + FCAW filling cap welding; cellulose electrode down-to-bottom welding + flux-cored self-protected welding wire filling cap welding.
In the petroleum, petrochemical, and other industries, TIG welding base + MAG solid welding wire filling and capping welding process is often used. After strict welding process evaluation and the use of the reverse crescent-shaped welding method, the weld excess height is low and the shape is beautiful. The X-ray flaw detection pass rate can reach 100%.
Post time: Apr-09-2025