How to identify the quality of 316L stainless steel plate by chemical analysis

The main factor affecting the material properties and product quality of 316L stainless steel plate etc. stainless steel products is the chemical composition of the material. Therefore, in the standard of stainless steel materials, most materials are required to ensure the chemical composition, and some even regard it as the main quality indicators of the material varieties. The chemical composition of 316L stainless steel plate can be identified and analyzed by many chemical and physical methods. At present, chemical analysis and spectral analysis are widely used. In addition, the spark identification method with simple equipment and fast identification speed is also a practical and simple method to identify the composition of 316L stainless steel plate.

Chemical analysis is based on the corresponding chemical reaction to determine the composition of 316L stainless steel plate material. Chemical analysis can also be divided into two types: qualitative analysis and quantitative analysis. Through qualitative analysis, we can identify which elements are contained in 316L stainless steel plate material, but we can not determine their content. Quantitative analysis is used to accurately determine the proportion of various elements in the 316L stainless steel material. Therefore, quantitative analysis is mainly used in actual production.

Quantitative analysis can also be divided into gravimetric analysis and volumetric analysis. Gravimetric analysis is the use of appropriate means of separation, so that 316L stainless steel plate in the determination of elements and other components are separated, and then use weighing method to measure the content of elements. Volumetric analysis uses a standard solution (a solution of known concentration) to react completely with the element in the metal, and then calculates the element content in the 316L stainless steel material according to the volume of the standard solution consumed.

The principle of spectroscopic analysis is that various elements produce their own spectra under the excitation of high temperature and high energy. The method of determining the chemical composition and the approximate content of 316L stainless steel plate by the characteristic spectrum formed after the element is excited is called spectral analysis method. In general, the sample is excited by external energy such as arc, electric spark, laser and so on, so that the elements in the 316L stainless steel material under test emit characteristic spectrum. After that, it is compared with the spectroscopic tables of chemical elements for analysis.

The last one is the spark identification method, which is mainly used to identify the composition of 316L stainless steel plate. Because of friction and high temperature, the number, shape, bifurcation and color of the sparks formed by oxidation of various elements and particles will be different when grinding, so as to identify the chemical composition of the 316L stainless steel plate material and the approximate content.