Method for detecting subsurface crack of casting blank

Abstract

The invention discloses a method for detecting subsurface cracks of a casting blank. The method includes the steps of: polishing away surface scale on a part to be detected of a casting blank to form a detection surface and to ensure the smoothness of the surface to be detected, and cleaning the surface to be detected; spraying a penetrating agent on the surface to be detected, wherein if the casting blank has micro cracks or cracks, the penetrating agent penetrates into the depths of the micro cracks or cracks by using the capillarity principle; cleaning the penetrating agent on the surface to be detected, spraying a photographic developer on the surface of the surface to be detected, and expressing the penetrating agent in the micro crack or cracks on the photographic developer under the effect of the capillary principle; if the casting blank has micro cracks or cracks, expressing the stripes according to the size and length of the cracks on the surface to be detected, wherein if no stripes appear, then the casting blank has no cracks or cracks. The method provided by the invention can improve the detection accuracy on surface quality of the casting blank, and avoid the influences on the subsequent production due to undetected defects of microscopic subsurface micro cracks.

Description

technical field [0001] The invention relates to a steel casting technology, in particular to a method for detecting subcutaneous cracks of a slab. Background technique [0002] In the traditional steelmaking-continuous casting-steel rolling production line process, the continuous casting billet is the end product of steelmaking and also the billet of rolling steel, so the continuous casting product is a key link in the production process, and the surface quality of the billet is Judgment and tracking have vital guiding significance for the entire production line. [0003] Subcutaneous cracks are a typical billet quality problem. The main factors that produce billet surface cracks are: whether the chemical composition of the molten steel itself is scientific, the amount of harmful gases and inclusions contained in the upstream molten steel, the condition of the casting machine itself, and the overall quality of the casting machine. The accuracy of the arc alignment, whether ...

AI Technical Summary

Problems solved by technology

[0014] To sum up, there is currently a lack of a detection method that can accurately detect the small micro-cracks under the skin of the slab without causing damage to the slab, and must ensure a short cycle and a fast detection method.

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