Seamless steel pipes are made of a whole round steel perforated. Steel pipes with no welds on the surface are called seamless steel pipes.
According to the production method, seamless steel pipes can be divided into hot-rolled seamless steel pipes, cold-rolled seamless steel pipes, cold-drawn seamless steel pipes, extruded seamless steel pipes, jacked pipes, etc.
According to the cross-sectional shape, seamless steel pipes are divided into two types: round and special-shaped. Special-shaped pipes have various complex shapes such as square, oval, triangle, hexagon, melon-shaped, star-shaped, and finned pipes. The maximum diameter is 900mm and the minimum diameter is 4mm.
According to different uses, there are thick-walled seamless steel pipes and thin-walled seamless steel pipes. Seamless steel pipes are mainly used as petroleum geological drilling pipes, cracking pipes for petrochemical industry, boiler pipes, bearing pipes, and high-precision structural steel pipes for automobiles, tractors, and aviation.
Production Process
①Main production processes of hot-rolled seamless steel pipes (△Main inspection processes):
Preparation and inspection of tube blank △ → heating of tube blank → perforation → pipe rolling → steel pipe reheating → diameter determination (reduction) → heat treatment △ → finished pipe straightening → finishing → inspection △ (non-destructive, physical and chemical, Taiwan inspection) → warehousing
②The main production processes of cold-rolled (drawn) seamless steel pipes:
Blank preparation→pickling and lubrication→cold rolling (drawing)→heat treatment→straightening→finishing→inspection
The production process of general seamless steel pipes can be divided into two types: cold drawing and hot rolling.
