GB/T 15247-2008Microbeam analysis -- Electron probe microanalysis -- Guidelines for determining the carbon content of steels using calibration curve method (English PDF)

2.1 Overview

Determination of steel carbon content using a calibration curve, first prepare a suitable reference material. Accurate analysis particular attention to prevent detection test Like surface carbon contamination, to avoid pollution on the carbon content of the test results.

Samples and reference materials detected Kalpha line intensity of carbon required under the same experimental conditions and steps that sample preparation, speed Voltage, beam, beam spot size, count mode point analysis, line analysis steps and methods of backing deductions and so requires the same.

2.2 Reference Materials

For detection of the carbon content of the calibration curve, or the need for a set of suitable reference material. For example, the following reference materials.

--- Quenched from the austenite zone temperature of Fe-C solid solution. Series reference material should include a range of different carbon contents, and each parameter Test substance requires uniform composition;

--- Fe-C compound Fe3C [1].

Reference material and the sample under test carbon Kalpha peak shape will also not reduce the accuracy of quantitative analysis, and therefore can not be used.

2.3 Sample Preparation

2.3.1 Description

When the samples were prepared, and a carbon compound contamination largely formed in the sample surface affect the accuracy of the carbon content analysis. therefore when the sample preparation requires special attention to prevent such contamination. Reference materials and preparation of samples to be tested (mosaic, grinding and polishing) to protect Holding the same.

2.3.2 Mosaic

Typically the sample without mosaic, but in the analysis of small samples or irregular shape, the need for mosaic. We must recognize mosaic Materials will also become a source of carbon pollution. Many common mosaic material, such as phenolics, doped with copper, aluminum, graphite or resins, the choice to advance its assessment inlay material, to avoid sample contamination caused.

When the sample was analyzed mosaic, should try to choose a region near the center of the sample to detect the edges in order to avoid contamination by the inlay material Impact.

2.3.3 Polishing and cleaning

Prepared sample surface should be smooth, clean and dry. Metallographic samples were prepared in accordance with the requirements of standard sampling methods, such as the use of SiC sand Abrasive paper, the choice of a suitable size polishing paste polishing. The final polishing using a polishing agent with a non-carbonaceous material requirements, such as alumina powder Wait. After polishing, use ultrasonic cleaning to completely remove the sample preparation process may sample surface residual contaminants.

2.4 Carbon Kalpha line intensity detector

2.4.1 Electron beam energy and beam

Because carbon characteristic X- ray yield is low, and almost all of the base material of carbon Kalpha line has a strong absorption, so the carbon X- ray GB/T 15247-2008/ISO 16592:2006