PAO Severstal, one of the world's largest vertically integrated steel and mining companies, has resumed supplies to Alfapipe, a spiral welded pipe manufacturer in Algeria. For the client, metallurgy produced 26 thousand tons of strip steel of grade X70.
Steel grade X70 has a sufficiently high strength in combination with the retention of viscous properties, including at low temperatures. This allows it to be used for the construction of high pressure pipelines. To ensure the entire range of properties, manufacturability of production and processing of metal, strict adherence to technological parameters at all stages is required - from steelmaking to shipment.
Rolled metal was produced at Mill 2000 of the Cherepovets Metallurgical Plant (CherMK, part of the Severstal Russian Steel division) ... Opportunities for the selection of the optimal technology have significantly expanded after the reconstruction of the laminar installation of the 2000 mill. The investment project worth 2 billion rubles, implemented in the fall of 2019, provided for the replacement of the old installation in 1975 with equipment of a new generation. The modernization made it possible to improve the cooling accuracy of the strip after hot rolling in the 2000 mill to obtain uniform mechanical properties along the length and width. This will help avoid problems with Severstal's metal processing in pipe production. In addition, the new laminar cooling unit makes it possible to obtain the properties of rolled metal, which previously could only be achieved with the help of additional alloying (consumption of ferroalloys), that is, it allows to reduce the cost.
To fulfill the order, employees of the Directorate for Technical Development and Quality of the Severstal Russian steel ”and the production of flat-rolled products CherMK have adjusted the technology of production of steel grade X70, taking into account the capabilities of the new equipment. As a result, the specialists changed the microstructure of rolled products and achieved higher strength due to a significant increase in the cooling rate.
Another requirement was rather tight thickness tolerances along the entire length of the coil. The recent modernization of hydraulic pressure devices at mill 2000 helped the metallurgists cope with this task.
The production and delivery of rolled metal at the request of the client was carried out in batches within three months - from July to September.
Severstal is increasingly active develops export directions for the supply of metal products to clients of the oil and gas industry. To this end, both the production technology and logistics delivery schemes are being improved, taking into account the requirements of consumers, ”said Kirill Kirill Kiryushkin, Senior Manager of the Directorate for Energy Companies at Severstal.