Formation of Dispersed Acicular Ferrite in the Structure of Cold-Resistant Welds at Temperatures down to –70°C during Manual Arc Welding at the Assembly of Metal Structures Made of 10KhSND Steel: Part 1

• Published in: Inorganic materials : applied research 2021-11, Vol.12 (6), p.1467-1475
• Main Authors: Sokolov, G. N., Litvinova, T. R., Zorin, I. V., Kharlamov, V. O., Artem’ev, A. A., Kyazimov, F. A., Titov, K. E.
• Format: Article
• Language: English
• Subjects: Acicular structure; Aluminum; Arc welding; Carbon nitride; Cerium oxides; Chemistry; Chemistry and Materials Science; Coated electrodes; Cold; Cold welding; Crystallization; Detonation; Diamonds; Dispersion; Ferrites; Heat treating; Impact strength; Industrial Chemistry/Chemical Engineering; Inorganic Chemistry; Iron constituents; Low alloy steels; Low temperature resistance; Materials Science; Metal Sciences. Metallurgy; Metallurgical analysis; Nanoparticles; Nonmetallic inclusions; Titanium; Titanium nitride; Toughness; Weld metal; Welded joints; Welded structures
• ISSN: 2075-1133; 2075-115X
• DOI: 10.1134/S2075113321060241

The analysis of metallurgical methods that improve the quality of electrodes for manual arc welding of low-carbon and low-alloy cold-resistant steels is presented. It is shown that it is possible to increase the technological and operational properties of welded joints at ultralow climatic temperatures down to –70°C to the level of world analogs by microalloying the weld metal with nitrogen, titanium, cerium oxide, and diamond nanoparticles of detonation origin. The composition of the modifying mixture introduced into the electrode coating is revealed. The cumulative effect of its constituent components on the impact toughness of the weld metal on 10KhSND steel was established during tests in the temperature range from –20 to –70°C. The weld metal structure consists mainly of dispersed acicular ferrite, reinforced with nanoparticles, presumably nitrides and carbonitrides of titanium and aluminum. It is shown that the centers of crystallization for acicular ferrite are microsized nonmetallic inclusions formed on superdispersed titanium nitrides. It was revealed that the impact toughness of the weld metal at below-zero climatic temperatures exceeds its values for seams welded using the massively imported LB-52U electrodes of the Japanese company KOBELCO. The results of the performed research make it possible to increase the cold resistance of welded structures for petrochemical and special purposes, based in the regions of the Far North of the Russian Federation.