Determinação do grau de encruamento ocasionado pela gravação do Número de Identificação Veicular (NIV) e suas consequências

Abstract

Automotive vehicles are constantly targeted for fraud regarding their individualized identification whose rewrite is the most used method by adulterators. The aim of this work was to measure the residual stresses present in the Vehicle Identification Number (VIN) marked by the manufacturer, to measure the residual stresses present after tamper process by criminal and to evaluate, based on the level of residual stresses, the effectiveness of a methodology for revealing this tampered number. Optical microscopy, scanning electron microscopy and energy dispersive spectroscopy techniques were used to the microstructural characterization of the plate where the VIN is marked. X ray diffraction method was applied to measure the residual stresses. The Fry's reagent was applied to reveal the original VIN that was obliterated. The characterization showed a composite compatible with low carbon steel. On the original VIN marking the residual stresses shows random (compressive and tractive) while that after obliterated all measures was compressive. The etching did not yield satisfactory results, that was attributed to low value of 0.2 mm required by ABNT NBR 6066/09, that entail in a low residual stresses value on the original VIN marking.