Precautions for the use of stainless steel welded pipes:
1. Generally, vertical external characteristics power supplies are used, with positive polarity in DC.
2. Suitable for welding thin plates under 6mm, with the characteristics of attractive weld bead shape and minimal welding distortion.
3. The protective gas is argon with a purity of. When the welding current is 50~50A, the argon flow rate is 8~0L/min; when the current is 50~250A, the argon flow rate is 2~5L/min.
4. The length of the tungsten electrode protruding from the gas nozzle is best at 4-5mm, 2-3mm for areas with poor shielding like corner welding, 5-6mm for areas with deep slots, and the distance from the nozzle to the workpiece should generally not exceed 5mm.
5. To prevent the occurrence of welding pores, ensure that any welding areas with rust, oil stains, etc., are thoroughly cleaned.
6. For welding steel, an arc length of 2~4mm is ideal, while for stainless steel, an arc length of ~3mm is preferable; longer arcs result in poor protective effects.
7. When aligning the base layer, to prevent oxidation of the backside of the weld track at the bottom, gas protection should also be applied to the backside.
8. To ensure effective protection of the welding pool by argon gas and facilitate welding operations, the tungsten electrode centerline should generally maintain an angle of 80° to 85° with the welding piece. The angle between the filler wire and the workpiece surface should be as small as possible, typically around 0°.
Features of stainless steel welded pipes:
Stainless steel welded pipes are produced continuously online. The thicker the wall thickness, the higher the investment in the equipment and welding machines, making it less economically and practically viable. As the wall thickness decreases, the return on investment ratio also diminishes. Generally, welded steel pipes have high precision, uniform wall thickness, and a high brightness on both the inside and outside surfaces (determined by the surface grade of the steel plate), and can be customized to any length. Therefore, they demonstrate their cost-effectiveness and aesthetic appeal in high-precision and medium-low pressure fluid applications.
Stainless steel welded pipes offer excellent compressive strength, corrosion resistance, and stress corrosion resistance, thus finding wide application across various fields. Why are stainless steel welded pipes becoming increasingly popular?
High Precision: Welded pipes are a deep-processed product of sheets, with the advantage of uniform wall thickness that is unmatched, and they can also be cut to any specified length with high accuracy. The welding process is simple, and the product specification range is wide, with a smooth surface and well-formed materials. The commonly used "welding-cold rolling" production process for stainless steel pipes involves cold-rolling coils cut to size and shaped, then welded into pipes, followed by cold rolling (drawing) to ensure that the weld's performance indicators are essentially consistent with the base material, thereby improving product quality and precision.
2. Economic & Eco-friendly: During the production of stainless steel welded pipes, the tube body undergoes even extrusion, followed by online bright annealing, resulting in a very smooth surface. A smooth surface is less prone to scaling, offering anti-scaling properties. This feature benefits both heat dissipation and reduces the need for frequent cleaning, saving time, effort, and money.
From the production and application perspective, stainless steel welded pipes are primarily used for conveying water, oil, air, and other general low-pressure fluids, as well as for heating hot water or steam. Some welded pipes are also employed in mining for compressed air, drainage, and shaft gas release. Stainless steel seamless pipes, on the other hand, can be used both for fluid conveyance pipelines in engineering and large equipment and for high-temperature, high-pressure fluid collection tanks and pipelines in power and nuclear power plant boilers.
