A plasma welding process of duplex stainless steel 2205 with bypass wire feeding

Abstract

The invention relates to the technical field of welding, and discloses a plasma welding process of duplex stainless steel 2205 with bypass wire feeding, comprising the following process steps: (1) steel plate cutting, (2) welding wire selection, (3) steel plate pretreatment , (4) splicing and positioning of steel plates, (5) installing back protection tooling, (6) filling back protective gas, (7) welding; the welding process parameters are: the polarity of the power supply of the plasma arc welding equipment is DC positive connection, plasma arc welding equipment The tungsten electrode type of the arc welding torch is cerium tungsten electrode WCe‑20, and the diameter is φ4.0mm; the back shielding gas and the welding front shielding gas are a mixture of 98% argon and 2% nitrogen, plasma gas, hood gas It is argon gas with a purity grade of 99.99%; the plasma gas flow rate is 5.5~6.0L / min, the flow rate of the welding front shielding gas and the hood gas are both 25~30L / min, the welding current is 220~240A, the voltage is 26~28V, and the welding speed is 19~21cm / min, heat input 0.98-1.27KJ / mm. The invention can improve welding efficiency, reduce production cost and improve welding quality at the same time.

Description

technical field [0001] The invention relates to the field of welding technology, in particular to a plasma welding process of duplex stainless steel 2205 with bypass wire feeding. Background technique [0002] Duplex stainless steel 2205 is a composite stainless steel composed of 22% chromium, 3.3% molybdenum and 5.8% nickel-nitrogen alloy. It has high strength, good impact toughness and good overall and local stress corrosion resistance. Compared with the first-generation duplex stainless steel, 2205 duplex stainless steel further increases the nitrogen content to enhance the stress corrosion resistance and pitting resistance in acidic media with high chloride ion concentration. Nitrogen is a strong austenite forming element, adding to duplex stainless steel can not only improve the strength of steel, but will not significantly damage the plasticity and toughness of steel. [0003] The excellent internal corrosion performance and mechanical properties of duplex stainless s...

AI Technical Summary

Problems solved by technology

The prior art usually adopts welding methods such as electrode arc welding (SMAW), submerged arc welding (SAW), manual argon arc welding (TIG), etc., and the specific welding method is multi-layer welding, and its welding efficiency is low on the one hand. On the other hand, when using multi-layer welding, it is necessary to cooperate with the welding of each layer to implement cooling and temperature control of each layer, resulting in poor overall cooling control stability, which will affect the accuracy of the ratio of the two-phase structure after welding, thereby reducing Comprehensive performance of duplex stainless steel 2205

In addition, the traditional welding method requires a lot of pre-weld preparation work, requires opening grooves, consumes a large amount of welding consumables, and has large welding deformation, making it difficult to guarantee the quality

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