engleski

Influence of Niobium Content on Strain Amount in Lüders Bands in Niobium Microalloyed Steel

In this paper, the influence of niobium content on strain amounts in various areas of Lüders bands propagation was investigated. The tests were simultaneously performed by a static tensile test and a digital image correlation in microalloyed steel with the same base chemical composition but with different addition of 0.035% and 0.06% of niobium. Strain changes were determined by a qualitative and quantitative analysis using a digital image correlation in the area of maximum strain amount behind the Lüders band front (position 1), on the Lüders band front (position 2) and in front of the Lüders band front (position 3). Different deformation behavior of Lüders bands was found in the examined samples with different addition of microalloying element niobium. The area behind the Lüders band front (position 1) showed the highest strain amounts in relation to the other two examined areas. The steel with 0.035% of niobium indicates higher strain amounts in the area of maximum strain behind the Lüders band front (position 1) compared to the steel with 0.06% of niobium which is associated with dislocation density and grain size. This difference is lower on the Lüders band front (position 2) and in front of the Lüders band front (position 3). There were no significant changes in the strain amount with the change of niobium content.

Lüders bands ; Dislocation density ; Niobium microalloyed steel ; Cold deformation

Glavni autori: Brlić, Tin; Rešković, Stoja