Corrosive agent and method for displaying as-cast structure grains of chromium and molybdenum steel

• Main Author: TIAN LISHENG
• Format: Patent
• Language: Chinese; English
• Published: 15.09.2023
• Subjects: CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; METALLURGY; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLICMATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASSC23 AND AT LEAST ONEPROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25; NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; PHYSICS; TESTING

The invention provides a corrosive agent and method for displaying chromium and molybdenum steel as-cast structure grains, the corrosive agent is prepared from nitric acid, sulfuric acid and water, the volume concentration of nitric acid in the corrosive agent is 20-30%, and the volume concentration of hydrochloric acid in the corrosive agent is 20-30%; the method for displaying the chromium and molybdenum steel as-cast structure grains comprises the following steps that (1) a chromium and molybdenum steel as-cast sample to be detected is machined, the test surface roughness Ra is smaller than or equal to 1.6 micrometers, and oil stains and machining scars are not allowed to exist on the surface of the sample; (2) immersing the sample treated in the step (1) into the corrosive agent for normal-temperature corrosion; and (3) washing and blow-drying the corroded sample, and observing and measuring the chromium and molybdenum steel as-cast structure grains. According to the technical scheme, as-cast structure gr