Copper Nickel Welding And Fabrication Guide
Copper Nickel should be preserved appropriately, any sort of sludge should be discarded as well as residuary oil and grease for it to be in pristine condition for welding. Cupronickels can be easily welded using complete conventional methods. The genesis of the components that might precipitate micro fissuring and crack in the weld should be specified discrete surveillance. This largely emerges due to paint and crayon discerning markings, temperature attestation markers. It is crucial that the requisites for composing, specifically hygiene is cautiously practised. The joint region should be intensively cleansed preparatory to the welding. The region should be parched with a sterile cloth as they should be clear of remnants. Automated welding, comprehending orbital welding of pipe, might as well be suitable.
Types of welding processes:
Tungsten inert gas (TIG)/ Gas-shielded tungsten-arc (GTAW) – This is often used for affixing pipe parts and for connecting flanges and fittings as the prevalent implementation of cupronickel is in the structure of the proportionately narrow walled pipe.
Manual metal arc (MMA)/ Shielded metal arc (SMAW) – This method is apt for welding cupronickel and has the primacy of using comparatively inexpensive tools and appliances as it uses flux-laminated stick electrodes.
Gas-shielded metal arc (MIG)/ (GMAW) – This is often used for tacking as they are extremely fast and have elevated coefficient of thermal expansion to carbon steel. It is a very fitting and well-managed method.
Tack welding – Tack welds are fixtures to confine the activities of the surfaces that are to be welded. They are intended to be placed to erect a steady gap between the surfaces.
Welding Composition:
Welding cupronickel up to 3mm wide with a square butt assembling is attainable. Although, autogenous welding should not be undertaken as it will out-turn porous welds due to lack of effectual deoxidisers in the alloys. A bevelled construction should be used as the molten weld metal is not as fluid and handling of the torch or electrode is compulsory to secure amalgamation of the side walls. Welding in accustomed positions is viable and advisable to weld down-hand. This will permit higher accumulation rates and require less skill. Pre-heating the core metal prior to welding and tacking is not required. The interposes temperature is perpetuated below 150 degree Celsius to circumvent micro fissuring.
Welding Consumables:
The proportions of cupronickel rods are relative to the copper-nickel pipe specifications. The consumable would have 65 per cent nickel content, when disparate metals together, like steel to cupronickel, Mostly, consumables hold small components of titanium which are prepended to empower reaction with nitrogen and oxygen-filled atmosphere.
Welding Requirements:
- Assure coordination and cleanliness to ensure a full supply chain and production method.
- Preferably use 70-30 cupronickel consumables for the welds including 90-10 copper-nickel.
- Avoid tension concentrator hoisting like tapered bends in pipes.
- Do not utilise contaminated water or other such sources in the course of the welding procedure.
- Electrically encase copper-nickels from reduced noble alloys, when high resilience to biofouling is essential.
Post-welding treatment:
Heat treatment after welding is not needed. Imprints of splatter should be detached from the joints, comprehending slag from the MMA process. The foremost method to clean slag is with a revolving flap wheel or stainless steel brush.
Inspection:
- All the weld joints should be examined for contours, fissures, undercut, absent fusion and perforation.
- Fluid dye penetrant to descry possible surface obstruction.
- Radiography for sections that will be dispatched into deep waters and are exceedingly exposed.
All our copper nickel products are strictly compliance with national as well as international standards. Please contact us to know more about our cupronickel products.