Manufacturing Process
At present, carbon steel pipes can be divided into several categories according to the forming process, namely ERW steel pipes, LSAW steel pipes, SSAW steel pipes, and seamless steel pipes. Seamless steel pipes are further divided into hot extruded seamless steel pipes and cold drawn seamless steel pipes.
The main steps of the production process for ERW steel pipes are: uncoiling, straightening, forming, high-frequency resistance welding, removing welds, water cooling, sizing, cutting, testing, and warehousing.
The main steps in the production process of LSAW steel pipes are: steel plate inspection - trimming - pre bending - forging and cold forming - pre welding - internal and external welding - sizing - chamfering - UT inspection - water pressure inspection - appearance inspection - spray marking storage
The main steps in the production process of SSAW steel pipes are: uncoiling, cutting, butt welding, straightening, spiral forming, double-sided submerged arc welding, cutting, ultrasonic testing, water pressure testing, appearance testing, spray marking and storage.
We will introduce two production processes for seamless structural steel pipes. The production process of hot extruded seamless steel pipes and cold drawn seamless steel pipes.
① The main production processes (main inspection processes) of hot-rolled seamless steel pipes:
Preparation and inspection of pipe blank → heating of pipe blank → perforation → rolling of pipe → reheating of raw pipe → sizing (reduction) → heat treatment → straightening of finished pipe → finishing → inspection (non-destructive, physical and chemical, bench inspection) → storage
② The main production processes of cold-rolled (drawn) seamless steel pipes
Preparation of billets → Acid pickling and lubrication → Cold rolling (drawing) → Heat treatment → Straightening → Precision finishing → Inspection