Establishment of Physical and Chemical Properties Database of Controlled Stainless Steel Knives

The knife is one of the important scene evidences in the violent cases, which provides the clue about the crime. However, it often become very difficult to get the useful information about the crime due to lacking the database about the chemical and physical properties of knifes, which can compare these properties of scene and commercial knifes, and finally track the crime information. The thirteen kinds of steel knifes and eight kinds of raw material billets were investigated by these sample preparation procedures including cutting, inlay, polishing and etching; and the physical and chemical characteristics of different samples were analyzed, including microstructure, chemical composition, phase composition and Rockwell hardness. The rules of the physical and chemical characteristics of these different samples, which can provide the scientific evidences for tracking the manufacturer of different knifes, were recovered. The establishment method of controlled knives database was presented.