A hot corrosion and display method of low carbon er50-6 slab dendrites

Abstract

The invention relates to a thermal-etching and display method for a treelike crystal of a low-carbon ER50-6 ingot blank and belongs to the technical field of metallographic examination. The method comprises the following steps: truncating a sample, and grinding and polishing until no scratches exist on the surface of the sample; then preparing a corrosion solution by using hydrochloric acid, picric acid and water, putting the corrosion solution into a flask, heating the flask in a water bath of a constant temperature bath, and when the water solution in the flask is heated to 65-80 DEG C, putting the polished sample into the flask so that a polished surface comes into full contacted with the solution; corroding the sample at 65-80 DEG C for 10-30 minutes, taking out the sample, flushing the sample by water, drying the sample, and carrying out macroscopic shape sampling and treelike crystal interval measurement on the treelike crystal by virtue of a Leica SD6 stereoscope. The thermal-etching and display method has the advantages that the operation is simple, the acid consumption is low, a tedious reagent preparation step is omitted, the macroscopic shape of the treelike crystal of the low-carbon ER50-6 ingot blank can be rapidly and clearly displayed, and the method has a certain guiding significance to the research of a continuous casting process.

Description

technical field [0001] The invention belongs to the technical field of metallographic inspection, in particular to a method for hot corrosion and display of low-carbon ER50-6 billet dendrites. Background technique [0002] The dendrite spacing of the slab is affected by factors such as the chemical composition and the cooling rate of the continuous casting slab, and its size is closely related to the solidification structure and structure segregation. It can clearly display the dendrites, and then measure the dendrite spacing, which has important guiding significance for improving and optimizing the continuous casting process. At present, there are many methods for the corrosion and display of dendrites in China, but none of them are universal methods. A series of experiments are required for the dendrite display of each type of steel. Such as cold acid corrosion, hot acid corrosion, etc., which are commonly used in low-magnification, etc., the corrosion solution uses a 1:1...

AI Technical Summary

Problems solved by technology

Such as cold acid corrosion, hot acid corrosion, etc., which are commonly used in low-magnification, etc., the corrosion solution uses a 1:1 hydrochloric acid aqueous solution. The acid consumption is large, the surrounding environment is damaged and polluted, and dendrites cannot be clearly displayed

There are also a variety of corrosive solutions containing copper chloride, ferric chloride, and stannous chloride. This solution generally contains a variety of substances, which require accurate weighing and proportioning, and the proportioning is cumbersome.

And sometimes step-by-step erosion is required, and the erosion steps are more troublesome

After corrosion, the surface of the sample may be covered by copper precipitates, which cannot achieve the desired effect

[0003] It is planned to display dendrites on the low carbon steel ER50-6 slab. After patent retrieval, a large number of relevant patents and materials were consulted, and then the dendrite display test was carried out. It was found that the previous method was not suitable for the dendrites of the ER50-6 slab. The erosion of dendrites cannot be clearly displayed

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