Precipitation in vanadium bearing ultralow carbon strip steels

Abstract

Two novel Ultra Low Carbon steels were investigated, one based on combined vanadium and titanium additions and the second based on titanium only additions. Grain size and mechanical property measurements have been performed on continuous annealed samples previously subjected to 80% cold rolling reduction on both strip steel grades. The recrystallisation and grain coarsening characteristics of annealed ULC strips have been studied. The amount of precipitated species, under equilibrium conditions, at various annealing temperatures has also been calculated using MT-DATA thermodynamic modelling software. TEM characterisation coupled with EDX study of the precipitation sequences on continuous annealing strips was also performed. Precipitate studies of the novel ULC steels confirmed the major role of TiC precipitates in retarding the recrystallisation behaviour of ULC strip steels. The role of vanadium addition in ULC steel grades in reducing the recrystallisation temperature of ULC strip steels was also identified.

Precipitation characteristics during isothermal γ to α transformation and resultant hardness in low carbon vanadium–titanium bearing steel

“…2,7 In addition, the precipitation behaviour, precipitation mechanism and precipitation hardening have been further elucidated. [8][9][10][11][12][13][14][15][16] Moreover, the effects of isothermal holding temperature and time on sheet spacing, particle size and particle spacing and the orientation relationships between ferritic matrix and precipitated particles were also investigated. [8][9][10]13,15 It has been demonstrated that the precipitation reactions can take place during or after c to a transformation, resulting in interphase precipitation or random precipitation.…”

Influencing Factors of Nb-Ti Treated ULC-BH Steels’ Bake Hardening Property

“…The amount of solute carbon affects the desired BH-effect, so controlling the component and adjusting the technological parameter are the key points to produce the high grade ULC-BH steel. Research on the influence of the annealing process was less for the mechanical properties of V or V-Ti ULC-BH Steel [1][2][3]. In this article, we found the way to calculate the solution carbon content, analyzed effect of coiling temperature and annealing technological on BH2 value, expecting giving reference for producing ULC-BH steel.…”