Super Microwave Digestion System | Super microwave solves the difficulty of analyzing chromium in high-carbon steel

In the production process of stainless steel, the oxidation resistance and corrosion resistance of stainless steel are mainly improved by controlling the chromium content in stainless steel. Therefore, it is very important and necessary to establish a reliable and accurate analysis method for chromium content in stainless steel.

When using ICP-OES for chromium analysis, the pre-treatment often uses an electric heating plate to heat it and then digest it for sampling and testing. However, for high-carbon steel electric heating plate digestion, some carbon residues will remain, and the digestion is not thorough. The chromium element will react with carbon to form chromium carbide precipitation, affecting the test results. At this time, it is necessary to add strong oxidizing acids, such as perchloric acid and sulfuric acid. However, it has been reported in the literature that when perchloric acid is used to decompose the sample, about 10% of the chromium will volatilize in the form of CrOCl 3 , and the recovery rate is low. If concentrated sulfuric acid is used to increase the boiling point, although it can be completely digested, its high viscosity will affect the introduction of the test solution. Therefore, neither is the optimal solution.

This article introduces the pretreatment method of selecting super microwave digestion and using only aqua regia for digestion when measuring chromium in steel, and compares the test results with the method of heating with a hot plate.