From the perspective of seamless steel pipe(a53 seamless pipe) rolling technology, the following two points have formed restrictions on the further development of FFM rolling technology :
(1) Since the length of the mandrel is up to 30m, the length of the hot-rolled waste tube shall not be longer than 35m;
(2) The maximum outer diameter of the finished pipe is 7 inches. If this limit value is exceeded, the weight of the mandrel will be too heavy, the unevenness of the metal flow will increase, and the production will not proceed. In order to surpass the above limitations, the continuous tube rolling process will inevitably develop to the limited mandrel process.
Tube America 91 also published two articles emphasizing process management for the production of seamless steel pipes, namely;
(1) Strengthen "comprehensive quality management" to meet the needs of the steel pipe industry in the 21st century, the main content of which is statistical management of technological processes (abbreviated as SPC);
(2) JIT computer management system, including online production planning and management system, selection and determination of process parameters, production process arrangement and capacity calculation; production order issuing and process control, production site monitoring system.
The report of “Research on Wall Thickness Accuracy of Full Floating Mandrel Continuous Rolling Tube Mill” from University of Science and Technology Beijing (April 2008) stated that the slub control technology is adopted on the seamless steel tube continuous rolling mill, and the CEC control is adopted on the tension reduction mill. Technology, the precision of seamless steel pipes has been significantly improved, and the improvement in precision and the high production capacity that other units cannot reach have made the full floating mandrel continuous tube rolling process once again attracted people’s attention.