Seamless Steel Pipe

We are a seamless steel pipe manufacturer. Senhai especially produces welded steel pipes of large diameter and thick wall thickness in ERW, LSAW and SSAW. Anti-corrosion layers can also be done in our factory.

Seamless steel pipe is a kind of circular, square and rectangular steel with hollow section and no joints around. Seamless steel tube is made of steel ingot or solid tube blank by piercing and then by hot rolling, cold rolling or cold drawing.

Seamless Steel Pipe

Seamless steel pipe has a hollow section, which is widely used as a pipeline for conveying fluid. Compared with solid steel such as round steel, the steel pipe has a lighter weight when the bending and torsional strength are the same. It is a kind of economic section steel, widely used in manufacturing structural parts and mechanical parts, such as steel scaffold of petroleum drill, etc.

Seamless steel pipe production has a history of nearly 100 years. In 1885, German Mannesmann brothers first invented the two roll cross rolling piercer, and in 1891, they also invented the periodic pipe rolling mill.

In 1930s, because of the adoption of three roll pipe rolling mill, extruder and periodic cold rolling mill, the variety and quality of steel pipes were improved. In the 1960s, due to the improvement of the continuous rolling mill and the emergence of the three roll piercer, especially the success of the application of the tension reducing mill and the continuous casting billet, the production efficiency was improved, and the competitiveness of seamless pipe and welded pipe was enhanced.

Since 1953, China has attached great importance to the development of seamless steel tube industry, and has initially formed a production system for rolling various large, medium and small pipes.

Carbon Steel Pipe

Application and classification of seamless steel pipe

Application: seamless steel pipe is a kind of economic section steel, which plays an important role in the national economy. It is widely used in petroleum, chemical industry, boiler, power station, ship, machinery manufacturing, automobile, aviation, aerospace, energy, geology, architecture and military industry.

Classification:

① according to the section shape: circular section pipe and special section pipe

② by material: carbon steel pipe, alloy steel pipe, stainless steel pipe, composite pipe

③ according to the connection mode: threaded connection pipe and welded pipe

④ according to the production mode: hot rolling (extrusion, jacking, expansion) pipe, cold rolling (drawing) pipe

⑤ by use: boiler pipe, oil well pipe, pipeline pipe, structural pipe, fertilizer pipe

Production process of seamless steel pipe

SMLS Steel Pipe

① main production process (main inspection process) of hot-rolled seamless steel pipe:

Preparation and inspection of tube blank → heating of tube blank → piercing → rolling tube → reheating of raw tube → sizing (reducing) diameter → heat treatment → straightening of finished tube → finishing → inspection (non-destructive, physical and chemical, bench inspection) → warehousing

② main production process of cold rolled (drawn) seamless steel pipe:

Billet preparation → pickling and lubrication → cold rolling (drawing) → heat treatment → straightening → finishing → inspection