Weld joint metallographic corrosion method

Abstract

The invention discloses a weld joint metallographic corrosion method. The method comprises the following steps of: S1, grinding a detected surface of a metallographic sample; S2, corroding the detected surface by adopting a nitric acid alcohol solution; S3, after scratches on the detected surface disappear visually and the contour of a welding seam is visible, stopping corrosion; S4, washing the detected surface with water; S5, corroding the detected surface by adopting an ammonium persulfate aqueous solution; S6, after a second welding bead, a second fusion line and a second heat affected zone outline of the detected surface are visible, stopping corrosion; S7, washing the detected surface with water; and S8, blow-drying the detected surface. According to the weld joint metallographic corrosion method, the weld bead, the fusion line and the heat affected zone in the weld seam can be clearer and distinguishable, a back stain phenomenon affecting weld seam defect display is effectively avoided, inspection work of welding quality is facilitated, the efficiency of weld seam macroscopic metallographic inspection work can be improved, and the technical problem to be solved urgently is solved.

Description

technical field [0001] The invention belongs to the technical field of welding, and in particular relates to a method for metallographic corrosion of welding seams. Background technique [0002] Welding is an effective connection method between metal materials. The welding process is a heating and cooling process, including the weld metal formed by the melting and solidification of the metal in the weld zone and the heat generated by heat transfer near the base metal. In the affected area, welding metallographic inspection is an effective method to test welding quality. [0003] At present, the commonly used method is to use nitric acid alcohol corrosion solution to etch the inspected surface, and then rinse and dry it directly. The corrosion effect is unstable. During the inspection process, the welding seam fusion line and the welding bead are prone to blur and difficult to identify. It is often necessary to rework and re-corrode the inspection. , when there are defects s...

AI Technical Summary

Problems solved by technology

[0003] At present, the commonly used method is to use nitric acid alcohol corrosion solution to etch the inspected surface, and then rinse and dry it directly. The corrosion effect is unstable. During the inspection process, the welding seam fusion line and the welding bead are prone to blur and difficult to identify. It is often necessary to rework and re-corrode the inspection. , when there are defects such as pores and cracks on the weld, it is easy to produce solution staining phenomenon after the surface under inspection is corroded, resulting in the inaccurate judgment of defects and affecting the evaluation of weld quality

Images