Infrared Carbon Analyzers General Measurement Methods

The carbon in the infrared carbon-sulfur analyzer plays an important role in the performance of steel-steel analyzers: As the carbon content increases, the hardness and strength of the steel increase, and its toughness and plasticity decrease; conversely, as the carbon content decreases, the hardness and The strength decreases, while the toughness and plasticity increase. Infrared carbon-sulfur analyzer is a commonly used measuring instrument in the physics and chemistry analysis room of an enterprise. It is used to quantitatively analyze the contents of carbon and sulfur in metal and non-metal materials. It is widely used in metallurgy, casting, machinery, vehicles, and pump valves. , ore, environmental protection, quality inspection and other industries and areas, can be quickly and easily carried out raw material acceptance, furnace analysis, product testing and other stages of analysis and testing. Sulfur exists in steel and deteriorates the quality of steel, reducing its mechanical properties, corrosion resistance, and weldability. In particular, sulfur in steel, if it exists in the state of iron sulfide, due to its low melting point, can cause the phenomenon of "hot brittleness" of steel, ie, thermal deformation, cracking at high temperature, affecting the quality and service life of the product. Therefore, the lower the sulfur content in the steel, the better. In general, the sulfur content in ordinary steel is less than 0.050%, the sulfur content in tool steel is less than 0.045%, and the sulfur content in high-quality steel is less than 0.020%. In view of the important role of carbon and sulfur content in the quality and performance of steel, it is of great significance to examine the carbon and sulfur content in steel, that is, carbon and sulfur analysis. The carbon and sulfur elements in the steel stainless steel analyzer are burned through oxygen at high temperatures (1200°C to 1400°C). All of them can be converted into gases and generate CO2 and SO2. This is the basis for the combustion analysis of carbon and sulfur. The analysis principle of carbon and sulfur element analyzer is to oxidize the sample in a high-temperature furnace and generate and escape CO2 and SO2 gases. This method separates carbon and sulfur from metal elements and their compounds, and then determines CO2 and The content of SO2 is converted to the carbon and sulfur content of the sample.

Infrared carbon and sulfur analyzers generally measure the following:

1. Infrared spectrophotometry: The carbon and sulfur in the sample are heated at high temperatures under oxygen-rich conditions and oxidized to carbon dioxide and sulfur dioxide gas. After the gas is processed into the corresponding absorption tank, the corresponding infrared radiation is absorbed, transmitted by the detector as a signal, and the output is processed by a computer. This method has the characteristics of accurate, rapid, high sensitivity, high and low carbon and sulfur content are used, infrared infrared carbon and sulfur analyzer using this method, a higher degree of automation, the price is relatively high, suitable for applications with high analytical accuracy requirements.

2. Volumetric method: Commonly used carbon measuring methods are gas volumetric method and non-aqueous titration method. Sulfur measurement is iodometric method and acid-base titration method. In particular, the gas volumetric method for the determination of carbon and iodine content is the most rapid and accurate method for simultaneous determination of carbon and sulfur in China. The accuracy of infrared carbon and sulfur analyzers using this method has a lower limit of carbon content of 0.050%. The lower limit of content is 0.005%, which can meet the needs of most occasions.

3. Gravimetric method: Alkali asbestos is used to absorb carbon dioxide, and the carbon content is determined by "incremental". Determination of sulfur commonly used wet method, the sample with acid decomposition oxidation, converted to sulfate, and then in the hydrochloric acid medium was added cesium chloride, barium sulfate generated by precipitation, filtration, washing, burning, weighing the final calculation of sulfur The content.

The disadvantage of the gravimetric method of infrared carbon-sulfur analyzer is that the analysis speed is slow, so it is not possible to use it for the analysis of carbon and sulfur on the company's site. The advantage is that it has high accuracy, and it is still recommended as a standard method at home and abroad. It is applicable to standard laboratories and Research institute.