Plasma welding process with bypass wire feeding for austenitic stainless steel 254SMo

Abstract

The invention relates to the technical field of welding, in particular to a plasma welding process with bypass wire feeding for austenitic stainless steel 254SMo. The plasma welding process with bypass wire feeding for the austenitic stainless steel 254SMo comprises the following process steps of (1) cutting a steel plate; (2) selecting a welding wire; (3) pretreating the steel plate; (4) splicing and positioning the steel plate; (5) installing a back shielding tool; (6) filling a back shielding gas; and (7) welding, wherein the welding process parameters comprise: the power polarity of a plasma-arc welding device is a straight polarity direct current, a tungsten electrode type of a plasma-arc welding gun is a cerium tungsten electrode WCe-20, and the diameter is phi 4.0mm; the back shielding gas, a welding front surface shielding gas, a plasma gas and a dragging and covering gas use argon with the purity grade reaching to 99.99 percent; and a plasma gas flow is 5.5 to 6.0L / min, the flows of the welding front surface shielding gas and the dragging and covering gas are 25 to 30L / min, a welding current is 210 to 230A, the voltage is 26 to 28V, the welding speed is 20 to 22cm / min, and the heat input amount is 0.89 to 1.16KJ / mm. According to the plasma welding process with bypass wire feeding for the austenitic stainless steel 254SMo provided by the invention, the welding efficiency is improved, the production cost is reduced, and meanwhile, the welding quality is improved.

Description

technical field [0001] The invention relates to the field of welding technology, in particular to a plasma welding process of austenitic stainless steel 254SMo with bypass wire feeding. Background technique [0002] Super austenitic stainless steel 254SMo (UNS S31254), as the main material for desulfurization tower construction, has strong resistance to pitting corrosion, crevice corrosion, chloride ion stress corrosion and intergranular corrosion resistance, especially for acid radicals such as sulfate ions and chloride ions Ions have good corrosion resistance and can be used in extremely harsh working environments, so super austenitic stainless steel is more and more widely used. [0003] In the prior art, the welding process for the above-mentioned super austenitic stainless steel 254Smo mainly adopts electrode arc welding (SMAW), submerged arc welding (SAW), and manual argon arc welding (TIG). Hot crack defects. Especially for the welding of medium and thick-walled sup...

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Problems solved by technology

[0003] In the prior art, the welding process for the above-mentioned super austenitic stainless steel 254Smo mainly adopts electrode arc welding (SMAW), submerged arc welding (SAW), and manual argon arc welding (TIG). hot crack defect

Especially for the welding of medium and thick-walled super austenitic stainless steel, the base metal often needs to be beveled on one or both sides for multi-layer multi-layer welding, which will greatly increase the production cost and reduce the production efficiency. And the expansion of the heat-affected zone also leads to the increase of welding deformation

In addition, the traditional welding process requires a lot of pre-weld preparation work, requires opening grooves, requires a large amount of welding consumables, low welding efficiency, large welding deformation, prone to thermal cracks, and difficult to guarantee quality

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