DEVELOPMENT OF PROCESSING TECHNOLOGY FOR SHAPES OF LOW-ALLOYED HIGH STRENGTH STEELS MICROALLOYED WITH VANADIUM

摘要

Vanadium or vanadium+niobium complex additives to a low-carbon ferrite-bainitic steel ensured strength classes 450 and 500 in combination with high impact strength in the hot-rolled sections used for the rail-wagon building. Structure examinations have shown that the high strength obtained in sections with a flange thickness of 20.5 and 13 mm made of steels 12Mn2MoVCu and 08Mn2MoVNbCu is due to the presence of a rather finely dispersed ferrite and bainite formed during rolling and cooling, as well as the vanadium and niobium carbonitrides precipitating in ferrite. Microalloying of steel grade 10CrNiCuP with vanadium (analogue to a widely renowned corrosion-resistant steel grade Cor-Ten A) made it possible to obtain strength class 420 for bent shapes used for the railcar manufacturing.