000			01852nam a2200205 4500
001			376011
090			_a376011
100			_a20151020u y0pory50 ba
101			_aeng
200			_aRestoration of obliterated engraved marks on steel surfaces by chemical etching reagent _bRecurso eletrónico _fQingfang Song
311			_aResumo inserto na publicação. Ficheiro de 1,22 MB em formato PDF (4 p.).
330			_aChemical 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.
461			_dMay 2015 _vVol. 250, n. 1-2 _tForensic Science International _x0379-0738 _pp. 33-36
606			_aQUÍMICA FORENSE _9343048
606			_aMARCAÇÃO DE OBJECTOS _9343973
606			_aVEÍCULO AUTOMÓVEL _9241256
606			_aESTUDO DE CASOS _9322367
700			_aSONG _bQingfang _9350457