Welding method of super duplex stainless steel 2507

Abstract

The invention discloses a welding method of super duplex stainless steel 2507. The method comprises the steps that semi-automatic GMAW is adopted; a welding material adopted in welding is a solid welding wire; protection gas adopted in welding is mixed gas including 75% of argon and 25% of helium; a welding groove is ground into a double-face V shape; oil dirt and water within the 25 mm range of the interior and the two sides of the groove are cleaned; the numbers of the welding layers of the welding groove is 4, 3, 2, 1, 5, 6 and 7 from top to bottom, and according to the welding parameter table, welding is carried out as the specific welding method; the temperature between welding layers is controlled to below 100 DEG C; the welding line energy is controlled to 9.0 to 10.5 Kj / cm. Throughthe method, the tensile strength and the low-temperature impact toughness of a welding line joint can be improved, plasticity and corrosion resistance are excellent, welding line metal and base metalare well fused, the welding material utilization rate is obviously improved, energy saving effect is improved, generation of harmful smoke is reduced, and stability and reliability of welding line joint quality are ensured.

Description

technical field [0001] The invention relates to a stainless steel welding method, in particular to a super duplex stainless steel 2507 welding method. Background technique [0002] Super duplex stainless steel refers to a duplex steel with PREN>40, containing 25% chromium Cr and high molybdenum Mo (>3.5%), and high nitrogen N (0.22-0.30%). The most commonly used one is grade 2507 (ie UNS32750), such as image 3 Shown is the chemical composition of UNS32750 super duplex stainless steel, which was successfully developed by French, Swedish, and British companies around 1991 and introduced to the market. [0003] Compared with high-alloy duplex stainless steel 2205, 2507 super duplex stainless steel has higher gold content; the balanced design of high chromium Cr, high molybdenum Mo and high nitrogen N in 2507 super duplex stainless steel makes it resistant to chloride ion corrosion The ability has been greatly improved, and at the same time, it performs well in crevice c...

AI Technical Summary

Problems solved by technology

Using this welding process for welding, the production efficiency is low, and the effective utilization rate of materials is low; the effective deposition of SMAW welding materials is about 55%, and GTAW is about 85%.

Not only that, a large amount of welding fume will be generated in the SMAW process, which will not only pollute the environment, but also cause obvious harm to the occupational health of the welders.

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