OREANDA-NEWS. August 22, 2012. A thickness of a uniform slab was finally changed into a thin in the middle and thick in the tail "Dog Shape" under the high temperature of 800  to 900 degress after 7 times of high speed continuous process, reported the press-centre of Baosteel.

This is a new breakthrough for Baosteel in steel rolling technology. Therefore, Baosteel became the first steel enterprise in domestic and minority in international to supply high grade coiled tubing with thick rolling pickling product in batch. Up to now, more than 500 tons of production has been supplied in batch.

Coiled tubing is also called flexible tubing, coil, or soft tubing. Coiled tubing equipment has the quality of pressure operation, continuous up and down with small volume, high operation speed, and low cost. Up to the 90th of last century, coiled tubing has been widely used in field workover, well drilling, well completion well test and other field in oversea countries. However, up to now, only few companies can produce and supply in global, as coiled tubing is one of the most leading high technologies in the oil and gas field.

Mainly used in the coiled tubing , thicken rolling pickling product is produced by cut the hot rolled pickling steel belt, tail docking in a straight seam welding. As coiled tubing has only 90 percent of fatigue life in the head and tail joint, to promote the fatigue life, generally, customers will specially order the pickling production with thin in the middle and thick in the tail. Up to now, only one or two steel oversea companies can supply the high grade coiled tubing with thicken rolling in global.

In August last year, to increase the fatigue life of coiled tubing, one of the companies in America hoped to supply the thicken rolling hot rolled pickling original volume with thin in the middle and thick in the tail when communicating with Baosteel. To satisfied customers' needs of the new production , the manufacture department, hot rolling mill, equipment department, research institute and other departments responsed quickly, and made the trial supply of production plan.Under the high speed of production line, Baosteel should not only ensure the thickness requirements in the middle and tail, but also has the strict unified standard for the yield, tensile, strength, meanwhile, they also has a high demand for the inner quality of slab. As the current production information system didn't support the thicken rolling production, special manual intervention way was used.

In Octomber of last year, Baosteel delivered the first thicken rolling test material successfully. After that, each department made efforts together and overcome different unexpected problems during the production of thicken pickling production in batch and finally achieved to supply more than 5,000 tons in batch.

Recently, according to customers' feedback, Baosteel thicken rolling pickling production to produce high grade coiled tubing has passed the comprehensive test, and the production thickness accuracy control was superior to similar advanced companies in the world. Next step, Baosteel will develop thicken rolling automatic control model to create conditions for stable supply in batch.