Possibility of obtaining rolled sheet from white iron with increased plasticity

Abstract

Рroblem In the work, a study of the technology of manufacturing sheet metal up to 2 mm thick from white ledeburite cast iron alloyed with vanadium was carried out. Сast-iron purveyances forged preliminary. After forging purveyances were rolled with the different wringing out. At rolling a total degree of deformation was 70%. The additional annealing helped to bring down hardness of sheet and moulding of pipes became possible. White cast-iron has high plasticity because there are phase transformations in a vanadium eutecticum cementite. Goal. The goal of work is a study of sheet rolling of white cast-iron’s bars to use for the armour and weld-fabricated pipes. Methodology. Experimental cast iron contains 2.7 - 2.85% C and up to 2% V. 30 kg of castings were melted. The total degree of deformation was 70%. After forging, rolling was carried out on a two-roll laboratory mill on rolls with a smooth barrel. Results. The technological scheme for the production of white cast iron forgings is applied, which includes preliminary annealing, forging with a degree of deformation from 10 to 15%, intermediate annealing and final forging with a total ε=70%. Оriginality The use of carbide transformation in vanadium-doped cementite made it possible to carry out combined pressure treatment and obtain sheets up to 2 mm thick from iron castings Preliminary hot forging greatly stimulates and accelerates the process of cementite disintegration into austenite and vanadium carbides during high-temperature exposure. Rolling of forging blanks was carried out and the influence of thermal and deformation parameters on the structure of cast iron was investigated. Рractical value. Application of final heat treatment after deformation of cast iron provides a level of mechanical properties that corresponds to the properties of high-strength armor steels, and the hardness indicators even exceed them. Thinner sheets of such cast iron can be used to create compositions of multilayer armor with increased ballistic resistance from several materials with different properties.