Detection method for sulfur-containing inclusions in steel

Abstract

The invention relates to the technical field of quality detection of continuous casting production in ferrous metallurgy and particularly relates to a detection method for sulfur-containing inclusions in steel. According to the detection method, magnetic impurities in mixed liquid are removed in a magnetic separation manner, non-magnetic iron-containing compounds are converted into iron particles or magnetic iron-containing compounds, and the iron particles or the magnetic iron-containing compounds are removed in a magnetic separation manner, so that the influences caused by the non-magnetic iron-containing compounds to the detection of a target sulfur-containing inclusion are reduced, and a detection result is relatively accurate. Besides, finally obtained inclusion powder is placed on a conductive carrier so as to be subjected to SEM detection or EDS detection, so that a three-dimensional shape characteristic map of the inclusion can be obtained, the shape of the target sulfur-containing inclusion can be comprehensively and accurately expressed, and therefore, the reliable and accurate basis is provided for subsequent researches. Besides, the sulfur-containing inclusions are not separated from a steel sample by virtue of an acid dissolution method, so that the detection method is applicable to the sulfur-containing inclusions dissolvable in acid.

Description

technical field [0001] The invention relates to the technical field of iron and steel metallurgical continuous casting production quality detection, in particular to a detection method for sulfur-containing inclusions in steel. Background technique [0002] During the solidification process of the continuous casting slab, there are many kinds of sulfur-containing inclusions in the steel, and among them, the plastic inclusions have a great influence on the quality of the steel product. Taking MnS inclusions as an example, although the precipitation size is not large, because MnS is a plastic inclusion, it is easy to deform and increase in size in the later rolling process, so it will cause great harm to steel products (such as rails) . Because large steel products are often overloaded, the formation of MnS inclusions will cause stress concentration at the matrix interface, and cracks will occur after long-term stress. MnS inclusions are precipitated at the end of solidifica...

AI Technical Summary

Problems solved by technology

The composition of AA anhydrous electrolyte is: 1% tetramethylammonium chloride (conductive agent) + 10% acetylacetone (complexing agent) + anhydrous methanol, but in AA solution, tetramethylammonium chloride, acetyl Acetone is highly toxic, unsafe and environmentally friendly, and tetramethylammonium chloride requires strict temperature control in order to easily improve the electrolysis efficiency and accelerate the filtration and collection of inclusions. slow

The extension of the filtration time leads to the Fe in the electrolyte 2+ A large amount of oxidation produces Fe 2 o 3 , affecting the collection and sample preparation observation of inclusions

The traditional anhydrous electrolysis method can extract the inclusions in steel, but there are always more or less defects in the filtration process or characterization process, such as the difficulty in characterizing the distribution and quantity of inclusions

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