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Information × Registration Number 0221U102884, 0118U000190 , R & D reports Title Development and investigation of electrode materials, technology and equipment for automatic high-efficient surfacing of inner surfaces of pipes by alloys resistant to abrasive and hydroabrasive wear popup.stage_title Head Judra Oleksandr P, Кандидат технічних наук Registration Date 10-02-2021 Organization E.O.Paton Elektric Welding Institute National Academy of scinces of Ukraine popup.description2  The objective of this research work is solving an urgent problem in mining and metallurgical industry, related to improvement of wear resistance of inner surfaces of pipelines, transporting highly abrasive slime and gas-dust mixtures. The development is based on creating new electrode materials and technology of the process of highly productive flux-cored strip open-arc hardfacing of inner pipe surfaces. Improvement of the hardfacing process productivity was achieved through application of flux-cored strip with a high fill factor (up to 65%) as electrode material. This allowed considerable increase of the process productivity of up to 15 kg of deposited metal per hour, as well as improvement of the hardening layer serviceability due to additional alloying. Two typesizes of flux-cored strips of the following cross-section are proposed: 10.0 x 3.0 mm for hardfacing 160 – 300 mm dia. pipes and 16.5 x 4.0 mm for more than 300 mm dia. pipes. Two new compositions of flux-cored strips were developed for hardfacing alloys of 500Kh30R and 500Kh30BR type. Boron alloying creates the conditions for formation of wear-resistant borides and carboborides, and markedly refines the deposited layer microstructure that improves its wear resistance. Niobium also reduces the size of the carbide component and has a positive impact on the alloy performance. Conducted investigations of the chemical composition, microstructure, physical and mechanical properties and wear resistance of the deposited layer proved that the optimum content of boron and niobium should be equal to about 1% of each, while their increase has a negative influence on hardening layer brittleness. At development of new flux-cored strips a lot of attention was given to the impact of the degree of filler powder compacting and its particle size distribution on their technological properties. As a result of the conducted studies, it was established that the optimum welding-technological properties of the flux-cored strips Product Description popup.authors White Oleksandr I Voronchuk Oleksandr P popup.nrat_date 2021-02-10 Close