Bimetallic composite plate welding method

Abstract

The invention discloses a bimetallic composite plate welding method. The method comprises the steps that grooves are machined, after bimetallic composite plates are connected in a butt joint manner, I-type grooves are machined in base layers, V-type grooves are machined in composite layers, the height of the I-type grooves is 0.5-2 mm lower than the thickness of the base layers, the angle of the V-type grooves ranges from 50 degrees to 70 degrees, and the width of the bottoms of the V-type grooves ranges from 3 mm to 8mm; base layer welding, transition layer welding and composite layer welding are conducted sequentially, and the weld bead height of the composite layers is not lower than that of the composite layer. By the adoption of the bimetallic composite plate welding method, the groove manner is simple, one-time efficient welding of base layer weld beads can be achieved, the welding cladding amount of the composite layers is reduced by reducing the width of the base layer weld beads, and thus the purposes that welding wires are saved, and the welding efficiency of the composite layers is improved are achieved.

Description

[0001] Technical field: [0002] The invention relates to the technical field of layered structure bimetal welding, in particular to a welding method for a bimetal composite plate. [0003] Background technique: [0004] For high H 2 S / CO 2 In the exploitation of highly corrosive oil and gas fields and oil and gas transportation, the traditional single anti-corrosion technology, such as adding corrosion inhibitors, using plastic inner coatings and using non-metallic pipes, etc., has been difficult to meet the needs in terms of corrosion resistance reliability and economic indicators. Although the use of corrosion-resistant alloy pipes can greatly improve the corrosion resistance of pipes, its high price and lower strength than carbon steel seriously restrict its application in oil and gas fields, and corrosion-resistant alloy pipes are only used as corrosion-resistant parts. There is only about one-third of the overall pipe, and the remaining part is used as a mechanical supp...

AI Technical Summary

Problems solved by technology

[0006] At present, the main method of domestic composite pipe production is to produce carbon steel pipe and stainless steel liner separately, and combine them by expanding or exploding. The problem of low mechanical properties

The research on the welding of metallurgical bonded bimetallic composite pipes has just started. The main welding method in the early stage is TIG (MAG), the groove type is V-shaped, and the welding sequence is to weld the cladding layer first, and then weld the base layer. The existing problem is that many welding passes lead to Low production efficiency and base welding heat input lead to poor corrosion resistance of the clad layer, and V-shaped groove surfacing welding is difficult to realize automatic production; the main welding method in the later stage is SAW+TIG (MAG), the groove type is X-type, and the welding sequence is The base layer is welded first, and then the cladding layer is welded. Although this welding method solves the problems of poor welding efficiency of the base layer and poor corrosion resistance of the cladding layer, the excessive width of the SAW weld leads to an increase in cladding layer deposition, resulting in a The use of secondary and stainless steel welding wire increases, the overall welding efficiency of the weld is still not high, and the production cost is also difficult to control

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