Method for detecting chromium content in steel and iron alloy

Abstract

The invention relates to a method for detecting chromium content in steel and iron alloy. The method comprises the steps of (1) digesting a sample by using an acid solution to prepare a solution to be detected; (2) dissolving chromium by using the acid solution to prepare a standard solution with definite chromium content, injecting the standard solution to a flame atomic absorption spectrometer, measuring light absorption values corresponding to standard solutions with different chromium concentrations under the condition that the ray has the wavelength of 357.9nm, and drawing a working curve; (3) placing the solution to be detected into the flame atomic absorption spectrometer, and measuring the light absorption value of the solution to be detected by using a chromium hollow cathode lamp under the condition that the ray has the wavelength of 357.9nm; (4) comparing the light absorption value with the working curve, measuring the chromium content in the solution to be detected, and then, calculating to obtain the chromium content in the sample.

Description

technical field [0001] The invention relates to a method for detecting chromium content in iron and steel alloys. Background technique [0002] At present, the determination method of chromium content in steel and alloy mainly adopts GB / T223.11-2008 "visual titration or potentiometric titration method" and GB / T223.12-1991 "chemical analysis method of steel and alloy, sodium carbonate separation-diphenyl Carbodihydrazide Photometric Determination of Chromium. [0003] GB / T223.11-2008 "Visual Titration or Potentiometric Titration" determines the content of chromium in steel and alloys. It can only test steel and alloys with a chromium content of more than 0.1%. When the chromium content is less than 0.1%, the test result will be low. Not ideal, the deviation will be larger. Another disadvantage of the above method is that the required reagents are more, the steps are many and complicated, and the time is long. During the titration process, the end point is not easy to cont...

AI Technical Summary

Problems solved by technology

[0003] GB / T223.11-2008 "Visual Titration or Potentiometric Titration" determines the content of chromium in steel and alloys. It can only test steel and alloys with a chromium content of more than 0.1%. When the chromium content is less than 0.1%, the test result will be low. Not ideal, the deviation will be larger

Another shortcoming of the above method is that the required reagents are more, the steps are many and complicated, and the time is long

During the titration process, the end point is not easy to control

Another point is that the price of silver nitrate in the required reagent is relatively expensive

[0004] GB / T223.12-1991 "Methods for Chemical Analysis of Iron, Steel and Alloys Sodium Carbonate Separation-Diphenylcarbazide Photometric Determination of Chromium Content" has some of the above-mentioned shortcomings, and also has some of its own shortcomings. Test steel and alloys with a chromium content of 0.005% to 0.500%, and when using this detection method, if the co-existing iron elements cannot be effectively shielded, the interference to the results will be great, resulting in deviation of the test results

Another disadvantage is that in the process of oxidation and separation, it is easy to cause low detection results due to insufficient separation.