Production process of hot-rolled stainless steel seamless pipes

There are 11 steps in the production process of hot-rolled stainless steel seamless pipes, which are to prepare the tube blank, heat the tube blank, pierce the tube, roll the tube, reheat, reduce the diameter, perform heat treatment, straighten the finished tube, and further refine the tube. Complete and inspect the steel pipes, and then send them to the warehouse if they are found to be correct. The raw material of seamless steel pipe is round tube billet. During the rolling process, the round tube billet is cut into a billet with a length of about 1 meter, and then the billet is transferred to the furnace and heated to about 1200°C. Temperature control during the heating process is very important. . After coming out of the furnace, a punching machine is used for piercing, mainly using a tapered Kun steel pipe empty machine with high production efficiency, good production quality, and large perforation diameter expansion. After perforation, a three-kun tension reducer can be used for cross rolling and continuous rolling to determine the diameter of the steel pipe. After the steel pipe is sized, it enters the cooling tower and is cooled by spraying water. After cooling, the steel pipe can be straightened. Then use a metal flaw detector to inspect the inside of the steel pipe, mainly to check whether there are cracks or bubbles inside. After the inspection, the numbers and specifications must be painted on the back of the steel pipes. After all the processes are completed, the batch of steel pipes can be sent to the warehouse.

Problems are prone to occur during the pouring process of stainless steel, mainly because the chemical elements in it are oxidized to form oxides. Doped in it, coupled with the high viscosity of molten steel, the nozzle is easily blocked. In addition, the thermal conductivity of molten steel is very poor, and its shapes after solidification are also different, so it is easy to cause cracks in continuous casting. The above problems can be solved through precise speed; in other cases, new advanced technologies can be used, such as automatic control of pouring liquid level without oxidation protection and electromagnetic stirring, etc., to increase the amount of continuous casting rings.

Our country is currently relatively weak in the testing of stainless steel pipes. Therefore, in terms of quality control of stainless steel pipes, it is necessary to refine the process and improve the equipment settings to improve the testing level. Among them, non-destructive testing is a very critical quality testing section. Manufacturers can use equipment such as flow ultrasonic combination and add ultra-testing and laser diameter measuring devices to the unit to inspect the internal inspection of steel pipes. After the inspection, the data will be directly analyzed and stored in the computer to improve the automation level of production.