Method for preparing SUS304 weld metallographic phase and quantitatively analyzing ferrite intensity

Abstract

The invention discloses a method for preparing an SUS304 weld metallographic phase and quantitatively analyzing ferrite intensity. The method for preparing the SUS304 weld metallographic phase comprises the following steps: sampling, inlaying, coarse grinding, fine grinding, polishing, corroding, cleaning, observing and the like. The method for quantitatively analyzing ferrite intensity of the SUS304 weld metallographic phase comprises the following steps: (1) performing gray-scale processing; (2) Gaussian smoothing; (3) performing threshold segmentation; (4) blocking; (5) calculating the white area proportion of each block; and (6) solving the variance of the white area proportion of each block. By adjusting the grinding method and time, selecting the types of polishing agents and corrosive liquid and adjusting the ratio and storage manner of the polishing agents and corrosive liquid, the scratch can be eliminated, so that the tissues completely and clearly appear, the operation is simple and feasible, and the human interference factor of corrosive tissues is small; and the image processing algorithm is high in precision, the portability is high, and the ferrite intensity in the metallographic phase is conveniently and accurately quantified.

Description

technical field [0001] The invention relates to the field of metallographic preparation and analysis, in particular to a method for preparation of SUS304 weld metallographic and quantitative analysis of ferrite density. Background technique [0002] Due to its excellent properties such as high strength, corrosion resistance, and ease of processing, SUS304 is widely used in aerospace, automotive, chemical and other industries. However, due to the difficulty in controlling the process parameters properly, its joints often have defects, such as joint embrittlement. , Uniform corrosion, pitting corrosion, stress corrosion cracking and thermal cracking of welds, due to the small thermal conductivity and large linear expansion coefficient, it is easy to form a columnar crystal weld structure with strong intergrowth crystal orientation. The above problems greatly limit its performance. Welding life. The metallographic analysis of welds is not only an important means to study the i...

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Problems solved by technology

In the patent "A method for distinguishing bainite in hot-rolled TRIP steel and calculating its three phases" (Application No.: 201110192697.3), the TRIP steel sample after electrolytic polishing and corrosion was detected by scanning electron microscope backscattering diffraction device (EBDS) , can identify and quantitatively analyze each phase, but requires high equipment and needs to be carried out on a scanning electron microscope equipped with a backscattering diffraction device, and the operation process is more complicated

At present, there is no relevant patent for quantitative analysis of SUS304 stainless steel weld metallography

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