Seamless Steel Pipe Manufacturing Process

Seamless steel pipe manufacturing process

In the sizing test, if the surface does not respond to cracks, the pipe must be cut by a cutting machine and cut into a blank of about one meter in length. Then enter the annealing process. Annealing needs to be pickled with acidic liquid. When pickling, pay attention to whether there is a lot of blistering on the surface. If there is a lot of blistering, it means that the quality of the steel pipe does not meet the corresponding standards. In appearance, cold-rolled seamless steel pipes are shorter than hot-rolled seamless steel pipes. The wall thickness of cold-rolled seamless steel pipes is generally smaller than that of hot-rolled seamless steel pipes, but the surface looks brighter than thick-walled seamless steel pipes. Much rough, without too many burrs.

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

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

The delivery state of hot-rolled seamless steel pipes is generally hot-rolled after heat treatment. After the quality inspection, the hot-rolled seamless steel pipe must be strictly hand-selected by the staff. After the quality inspection, the surface shall be oiled, and then followed by multiple cold drawing experiments, and the piercing experiment shall be carried out after the hot-rolling treatment. , If the perforation is too large, it must be straightened. After straightening, it is transferred by the conveyor to the flaw detection machine for flaw detection experiment, and finally the label is affixed, the specification is arranged, and then it is placed in the warehouse.

Taking the rolling of steel plate as an example, the thickness of the continuous casting billet is generally about 230mm, and after rough rolling and finishing rolling, the final thickness is 1-20mm. At the same time, due to the small width-to-thickness ratio of the steel plate, the dimensional accuracy requirements are relatively low, and the shape problem is not prone to occur, and the crown is mainly controlled. If there is a requirement for the organization, it is generally achieved through controlled rolling and cooling, that is, controlling the start rolling temperature and final rolling temperature of finishing rolling.