01852nam a2200205 4500 376011 376011 20151020u y0pory50 ba eng Restoration of obliterated engraved marks on steel surfaces by chemical etching reagent Recurso eletrónico Qingfang Song Resumo inserto na publicação. Ficheiro de 1,22 MB em formato PDF (4 p.). Chemical etching technique is widely used for restoration of obliterated engraved marks on steel surface in the field of public security. The consumed thickness of steel surface during restoration process is considered as a major criterion for evaluating the efficiency of the chemical etching reagent. The thinner the consumed thickness, the higher the restoration efficiency. According to chemical principles, maintaining the continuous oxidative capabilities of etching reagents and increasing the kinetic rate difference of the reaction between the engraved and non-engraved area with the chemical etching reagent can effectively reduce the consumed steel thickness. The study employed steel surface from the engine case of motorcycle and the car frame of automobile. The chemical etching reagents are composed of nitric acid as the oxidizer, hydrofluoric acid as the coordination agent and mixed with glacial acetic acid or acetone as the solvents. Based on the performance evaluation of three different etching reagents, the one composed of HNO3, HF and acetone gave the best result. May 2015 Vol. 250, n. 1-2 Forensic Science International 0379-0738 p. 33-36 QUÍMICA FORENSE MARCAÇÃO DE OBJECTOS VEÍCULO AUTOMÓVEL ESTUDO DE CASOS SONG Qingfang 0 PJ_04_010000000000000__ARTIGOS_DIGITALIZADOS 2022-06-06 403792 PJ PJ PJ04.01 - Artigos digitalizados 2022-06-06 0 AP