Manufacturing process and difference between stainless steel welded pipe and seamless pipe

Manufacturing process
Stainless steel welded pipe:
Raw materials: mainly steel plates or steel strips.
Process: After the unit and the mold are curled and formed, they are connected by welding process. Common welding methods include argon arc welding, high frequency welding, plasma welding, etc. There is generally a weld on the inner wall of the welded pipe, but after high-precision processing and polishing, the weld can be very smooth and not easy to detect.
Features: The production process of welded pipes is relatively simple, with high production efficiency and low cost, and can produce large diameter and thicker pipes.
Stainless steel seamless pipe:
Raw materials: round pipe billets are used as raw materials.
Process: Made by hot rolling, cold rolling, cold drawing or hot extrusion. There is no welding link in the production process of seamless pipes, so there are no welding points on the pipes.
Features: The manufacturing process of seamless pipes is complex, the production efficiency is relatively low, and the cost is high, but it can produce pipes with uniform wall thickness and high precision. Seamless pipes are usually used in occasions with high requirements for pipe precision and pressure bearing capacity.

Difference
1. Pipe wall performance:
The pipe wall of seamless pipes is uniform, with better pressure bearing capacity and mechanical properties. Seamless pipes are usually better than welded pipes in corrosion resistance, pressure bearing and high temperature resistance.
The wall thickness tolerance of welded pipes is very small, the wall thickness of the entire circumference is very uniform, and the steel pipe has high precision, but seamless pipes may be slightly inferior to welded pipes in wall thickness uniformity (especially high-precision welded pipes).
2. Corrosion resistance:
Generally speaking, the corrosion resistance of seamless pipes may be better than that of welded pipes, but welded pipes can also achieve high corrosion resistance through high-precision polishing and surface treatment.
3. Inspection requirements:
The inspection requirements for seamless pipes are usually more stringent, including internal flaw detection, water pressure testing, etc. to ensure their quality.
Welded pipes also need to be strictly inspected, including weld radiographic flaw detection, eddy current flaw detection, etc., to ensure the quality of the welds and the pressure bearing capacity of the pipes.
4. Price:
The production process of seamless pipes is complex and the cost is high, so the price is relatively expensive.
The production process of welded pipes is simple, the production efficiency is high, and the cost is low, so the price is relatively cheap.
5. Application scenarios:
Seamless pipes are mainly used in situations where there are high requirements for pressure bearing capacity, mechanical properties and corrosion resistance, such as petroleum, chemical, power generation, automobile, shipbuilding and other industries.
Welded pipes are widely used in heat exchanger pipes, fluid pipes, pressure pipes, mechanical structure pipes, urban landscape and other industries. Welded pipes are also commonly used for decorative pipes, product pipes, prop pipes, etc., because they have good surface effects and low costs.