The three steps of large-diameter thick-walled steel pipe production of are as follows:
The first production methods: from thick-walled steel pipe (plate, belt) directly into the welding pipe, the main process for the strip forming, welding, sizing. Features: less production processes, the project process is simple, the product production cycle is short, the product accuracy is slightly lower.
The second production method: from the thick-walled steel pipe (plate, belt) first direct welding into a certain size pipe, and then after cold drawn or cold rolled into a finished product tube, known as DOM welded steel pipe. The main process for the forming, welding, sizing, cold rolling or cold drawing (with mandrel or no mandrel), or continuous cold drawing (ie welding - cold drawn joint production line). Features: the production process dispersion, process and production cycle is long, covers an area of large, product size and accuracy, both inside and outside the surface smooth, mechanical properties and microstructure state.
The third mode of production: by the thick-walled steel pipe (plate, with) the first direct welding into a certain size pipe, into the continuous reducer to reduce the diameter into a finished product tube. The main process for the forming, welding, continuous cold reduction. Features: compact production process, simple process, the unit production efficiency, specifications range change fast, suitable for the production of small diameter and thin-walled welded steel pipe.
