Нове покоління сталей – нові зварювальні матеріали
In recent decades, the range of steels used in large-diameter pipes (LDP) production has changed significantly. Whereas previously most welds were made on low-carbon steels, and 09G2S and 10G2FB steels were the most widely used low-alloy steels, today there is a steady increase in the consumption of high-strength low-alloy steels. They are characterized not only by higher strength characteristics, but also by higher toughness and ductility as a result of lower content of harmful impurities, microalloying and the use of special thermomechanical treatment modes.
A new generation of steels means new welding materials. Already in the course of the first works on mastering the technology of manufacturing pipes from such steels, it was found that manganese-silicate fluxes (such as AN-60), which have been most widely used so far, cannot provide the possibility of producing weld metal close to the properties of the base metal. Fluxes of these grades are being replaced by agglomerated aluminate-basic (AB) or aluminate-rutile (AR) fluxes supplied by foreign manufacturers of welding materials, as they usually have a higher basicity than manganese-silicate (MS) fluxes.
Welding flux – is a granular powder that protects the welding process from air and also changes the chemical composition of the weld metal. During welding, the flux granules melt and emit gas, and when cooled, they form a slag crust. There are two types of welding fluxes based on the manufacturing method: melted and agglomerated (ceramic).
Agglomerated fluxes are a mixture of selected finely ground minerals from natural sources, partially heat-treated before manufacture, and metal additives, all components are thoroughly mixed and combined. In the foreign literature, fluxes of this type are called agglomerated fluxes, and in the documents of the International Institute of Welding and ISO they are classified as bonded fluxes.
Ukrtruboizol LLC uses only high-quality agglomerated fluxes from the world’s leading suppliers to produce LDPs for main gas and oil pipelines made of steels with strength class up to X80, which are also suitable for operation at low temperatures.
They guarantee the ductile properties of the deposited metal with excellent welding and processing properties; they allow welding at high speeds in combination with good impact strength. The resulting deposited metal contains less than 5 ml of hydrogen per 100 g of metal. The fluxes are characterized by an excellent current-carrying capacity of more than 1500 A. Even with very high local currents, the welding process remains stable. The weld seam is characterized by very good wetting, uniform flow and a very wide, flat profile. The fluxes contain specific components that decompose during welding and produce shielding gases. This gas shielding prevents atmospheric nitrogen from entering the weld pool.
The use of only modern high-quality welding materials in the production of LDP, careful observance of welding process parameters, and modern equipment for submerged arc welding allow Ukrtruboizol LLC to supply customers with products of guaranteed quality.
Ukrtruboizol is Ukraine’s largest producer of longitudinal SAW steel pipes with external anticorrosion and internal anticorrosion or smooth coatings for main gas and oil pipelines.
The plant’s products are certified for compliance with the requirements of national, interstate and international standards ISO 3183:2019, DSTU ISO 3183:2017 (ISO 3183:2012, IDT), API Spec 5L, DIN EN 10219-1,2, DIN EN 10217-1,3,5,6, DSTU 8943:2019, DSTU 9219:2023, Technical Regulations for Pressure Equipment, Cabinet of Ministers of Ukraine No. 27 of January 16, 2019, European Directive 2014/68/EU and the requirements of the Construction Regulation EC 305/2011/EU with the right to affix the CE mark.
The company has an integrated management system that meets the requirements of international standards: ISO 9001:2015, ISO 14001:2015 and ISO 45001:2018, which is confirmed by the independent certification body Bureau Veritas Certification. The welding process complies with EN ISO 3834-2, which is confirmed by the independent certification body TÜV AUSTRIA SERVICES GMBH.
