There are two main differences:
One, the material is different
1, welded steel pipe: welded steel pipe refers to the use of steel strip or steel plate bending and deformation of round, square and other shapes and then welded into the surface of the steel pipe with seams, the billet used in the welded steel pipe is a steel plate or strip steel.
2, seamless steel pipe: made from a whole piece of metal, no seams on the surface of the steel pipe, called seamless steel pipe.
Two, different classifications
1, welded steel pipe: according to the different welding methods can be divided into arc welding pipe, high-frequency or low-frequency resistance welding pipe, gas welding pipe, furnace welding pipe, Bonded pipe. According to the use is divided into general welded pipe, galvanized welded pipe, oxygen blowing welded pipe, wire casing, metric welded pipe, roller pipe, deep well pump pipe, automotive pipe, transformer pipe, electric welding thin-walled pipe, electric welding profile pipe and spiral welded pipe.
2, seamless steel pipe: seamless pipe hot-rolled pipe, cold-rolled pipe, cold-drawn pipe, extruded pipe, top pipe, etc.. According to the sectional shape, seamless steel pipe is divided into two kinds of round and shaped, shaped pipe has square, oval, triangular, hexagonal, melon, star, with finned tube with a variety of complex shapes. The maximum diameter is up to 650mm and the minimum diameter is 0.3mm, according to the different uses, there are thick-walled and thin-walled tubes.
Expanded Information:
Use
Seamless steel tubes have a wide range of uses. General-purpose seamless steel pipe is rolled from ordinary carbon structural steel, low alloy structural steel or alloy structural steel, with the highest production capacity, and is mainly used as a pipeline or structural parts for conveying fluids.
Seamless steel pipe has a hollow cross-section, used in large quantities as a pipeline for the transportation of fluids, such as pipelines for the transportation of oil, natural gas, gas, water and certain solid materials. Compared with round steel and other solid steel, steel pipe in the same bending and torsion strength, the weight is lighter, is a kind of economic cross-section steel.
Widely used in the manufacture of structural and mechanical parts, such as oil drilling rods, automobile driveshafts, bicycle frames, and steel scaffolding used in building construction, etc. Use steel pipe to manufacture annular parts, can improve material utilization, simplify the manufacturing process, save materials and processing time, has been widely used in the manufacture of steel pipe.
Baidu Encyclopedia - Seamless Steel Pipe