Preparation method of 42CrMo steel casting rolling forming ring member sample for EBSD testing

Abstract

The invention discloses a preparation method of a 42CrMo steel casting rolling forming ring member sample for EBSD (electron back-scattered diffraction) testing and belongs to the technical field of ring member forming process electron microscope sample preparation. The preparation method is characterized by including following steps: (1), cutting sample units Q: cutting sample units Q1, Q2 and Q3 with length c=5-8mm, width k=3-4mm and height h=2-3mm at different positions along a radial wall thickness direction in a middle section in the height direction of a 42CrMo steel casting rolling forming ring member; (2), grinding: grinding the sample on an automatic grinder until glossiness of the surface is 12-13 grade; (3), ultrasonically cleaning; (4), preparing electrolysis polishing liquid; (5), electrolytically polishing: adopting self-made electrolysis polishing equipment to conduct a polishing experiment, wherein voltage is 25-30V, current is 0.6-0.8mA and time is 50-60s; (6), cleaning: sequentially putting 4-5 beakers containing a certain amount of anhydrous alcohol; (7), pre-observing: observing a slightly-corroded indistinctly-visible crystal boundary on the surface of the sample under a metalloscope. The preparation method is simple and low in investment, and the sample prepared by the method can be used for EBSD observation under a scanning electron microscope to obtain clear crystal boundary orientated images.

Description

technical field [0001] The invention belongs to the technical field of electron microscope sample preparation in ring forming process, and in particular relates to a preparation method of 42CrMo steel casting roll forming ring sample used for EBSD test. Background technique [0002] 42CrMo steel is a medium-carbon low-alloy high-strength steel with good hardenability, ductility and creep properties. It is widely used in key bearing parts of bearing rings in major industrial fields such as aerospace, ships and national defense equipment. With the development of cold rolling and expanding technology for small and medium-sized bearing rings (outer diameter less than 200mm) and hot rolling and expanding technology for large bearing rings (over 200mm in outer diameter), the 42CrMo steel ring billet is deformed along its radial wall due to hot rolling and expanding. The thick direction has strong anisotropic mechanical properties, which is mainly related to the type of texture for...

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Problems solved by technology

[0003] The 42CrMo steel sample used for EBSD testing must ensure no surface stress layer (elastic and plastic stress), high flatness and smoothness, which cannot be achieved by current mechanical polishing methods, and there are problems such as long preparation period and low pattern recognition rate

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