Conditions for the production of pipe billets
As a tube billet for rolling on the KhTPR, KhPT type, welded and seamless pipes are used. Seamless stainless pipes, which are needed for the HPT mills, and welded pipes are manufactured in a variety of ways of pressing and hot rolling. Let’s consider some of them.
Types of blanks
The workpiece for HPT mills (medium or small sizes) is pipes that are rolled on larger HPT types, as well as stainless steel tubes obtained by cold drawing. The workpiece for XPRT mills is welded and drawn pipes from HPT mills and pipes from larger mills. For each pack of blanks, a special label should be placed on which the pipe size, the steel grade, the open hearth melting number, the package number of the pipe-welding and pipe-rolling shop, the route number, the open-hearth melting room number and the package number of the pipe-rolling shop will be indicated.
Quality of blanks
The surface of the pipe billet should be free from cracks, opaline, flaws, captive, shells, sunsets and dirt. The ends should be cut without burrs, perpendicular to the axis of the pipes. Also, the pipes must be straight. Deliveries of pipes are normalized by the following GOST: seamless pipes from stainless steel — 9940−72, seamless hot-rolled 8732−70, electrowelded -10 704−63, welded — 3262−75.
For pipes of intermediate dimensions made of alloyed or carbon steels that go for drawing and further cold rolling, there are large tolerances for wall thickness and diameter than the corresponding tolerances for finished pipes. For example, pipes of intermediate dimensions made of stainless steel have a tolerance of +12.5 (or 10%) over the wall thickness, and pipes with a diameter of up to 3.2 cm have an outer diameter of 0.5 to 1 mm, and pipes have a large With a diameter of 0.5 to 1.6 mm. When rolling a measuring intermediate billet that has a deviation of the average actual wall thickness (Sfact) from the nominal (Sfn), taking into account the nominal length of the billet (Lnom), its actual length (Lfact) is determined according to the formula: Lact = Lnom x Snom / Sfact. The workpieces for XTPP mills have the following tolerances for pipes of all sizes: wall thickness ± 0.1 mm, outer diameter +0.5 -0.2 mm.
In the warehouse of Electrovek-Steel LLC, there is always a high-quality rolled metal product. We offer stainless pipes at the best prices. It is formed taking into account technological features of production and does not include additional costs. All products are certified. The lead times for orders are minimal. Wholesale buyers receive preferential discounts.