The invention provides a dendritic crystal corroding agent for high nitrogen austenitic stainless steel and a preparation method thereof, and belongs to the field of inspection and analysis of steel billet at low magnification. The dendritic crystal corroding agent is prepared from 0.6-2.1 g of cupric chloride, 0.1-0.3 g of magnesium chloride, 1-3 g of ferric chloride, 100 mL of water, 9-12 mL of hydrochloric acid, 1-4 mL of nitric acid and 125-130 mL of absolute ethyl alcohol. The preparation method comprises the steps of step 1, based on the proportioning, adding in sequence water, cupric chloride, magnesium chloride, ferric chloride, hydrochloric acid, nitric acid and absolute ethyl alcohol, stirring uniformly, keeping the solution static for 5-15 minutes, and step 2, polishing the surface of the test surface of the austenitic stainless steel, corroding the surface with corroding agent for 2-5 minutes, waiting until the generation of clearly visible dendritic crystal solidified structure, then rinsing and blow-drying the test surface, then testing and observing the corrosion effect. The corroding agent can easily, quickly and effectively show the corrosion condition of the dendritic crystal of the high nitrogen austenitic stainless steel, can explicitly manifest the solid dendritic crystal structure, and can accurately manifest the solidification defects. The corroding agent is good in repeatability.

Dendritic crystal corroding agent for high nitrogen austenitic stainless steel and preparation method thereof

The invention discloses a corrosive agent for displaying a steam line under a high-temperature alloy heading state and a corrosion method of the corrosive agent. The corrosion method comprises the following steps of sampling a conventional sample; corroding the sample: adopting 90-105g of copper sulfate, 45-60ml of sulfuric acid and 240-280ml of hydrochloric acid to corrode the sample with voltage of 0.2-3 volts, and the electrolysis time is 1-8 minutes; and carrying out conventional observation and evaluation. A used chemical agent is chemically pure or analytically pure, and water is distilled water. The adopted copper sulfate is CuSO4.5H2O. By means of the corrosive agent and the corrosion method, the real distribution condition of the production steam line can be accurately and reliably observed, and the product quality can be effectively controlled.

Corrosive agent for displaying steam line under high-temperature alloy heading state and corrosion test method

A method for manufacturing a surface corrosion-resistant film. A corrosion solution comprises hydrochloric acid, nitric acid, sulfuric acid, water, copper sulfate, and ferric chloride. A corrosion reaction process is that: a casting needing to be corroded is placed in a corrosion tank, the corrosion solution is poured into the corrosion tank, and the corrosion solution needs to cover the surface of the casting; when a black substance diffuses from the surface of the casting, the corrosion reaction starts, and the corrosion time is 20-30 min; after the corrosion reaction is finished, the casting is taken out, a black product remaining on the surface of the casting after the reaction is brushed off with a hair brush, and then the casting is washed with clear water, to obtain a macrostructure having a bright surface. Workpieces subjected to anti-corrosion treatment are more resistant to corrosion, can withstand the treatment and processing of oil and gas fields, and can be used in different working conditions.

Method for manufacturing surface corrosion-resistant film

The invention aims at providing a macroscopic examination method for surface defects of an iron-based high-temperature alloy disc. The macroscopic examination method specifically comprises the following steps of (1) preparing of a macroscopic corrosion tank liquid; (2) cleaning of a part; (3) macroscopic corrosion; (4) cleaning; (5) treatment after macroscopic corrosion; (6) cleaning; (7) drying.The macroscopic examination method has the advantages that the process operation is simple, and the equipment requirement is simple; when a workpiece is processed by the macroscopic corrosion procedure, the clear and effective macroscopic corrosion layer can be obtained, and the processing purpose of examining the defects is realized.

Macroscopic examination method for surface defects of iron-based high-temperature alloy disc

The invention discloses a preparation method of a high purity gold microstructure sample. The preparation method includes the following steps that (1) a high purity gold sample is thermally embedded by adopting a thermal embedding material; (2) the embedded sample is ground on SiC water proof sand paper; (3) the ground sample is mechanically polished twice, brighteners are diamond polishing solutions of 2.5 [mu]m and 1.0 [mu]m, each polishing duration is 30s-3min, and the rotating speed of a polishing disk is 100r/min-200r/min; (4) the sample is corroded by a ferric trichloride+ hydrochloric acid+hydrogen peroxide+water mixed solution; and (5) the corroded sample is rinsed and dried, and then the microstructure of the high purity gold sample is observed under a microscope. According to thepreparation method, the ferric trichloride+ hydrochloric acid+hydrogen peroxide aqueous solution is taken as a corrosive liquid, the chemical property is stable, corrosiveness is weak, the harm to ahuman body is little and the corrosive liquid is safer than aqua regia.

Preparation method of high purity gold microstructure sample

The invention discloses a macrograin corrosion method for a monocrystal high-temperature alloy casting containing Re and/or Ru, belonging to the technical field of quality detection of a turbine blade serving as a core hot end part of an aircraft and airspace engine and a gas turbine for civilian use. A corrosive liquid used in the method comprises hydrochloric acid, nitric acid, sulfuric acid, water, copper sulfate and ferric trichloride. The macrograin corrosion method comprises the steps of firstly, placing a casting into a corrosion tank, pouring the corrosive liquid into the corrosion tank, and carrying out corrosion reaction for 20-30 minutes; after ending the corrosion reaction, taking out the casting, brushing away a black product left on the surface of the casting after the reaction is ended, then, flushing with clear water to obtain a macrostructure with a bright surface, and then, observing the macrostructure. According to the method, different corrosive media in a corrosive agent are utilized to simultaneously corrode a crystal boundary and a matrix or a strengthening phase at different speeds, and crystal grains with different orientations have remarkable symmetry errors, so that various surface defects in a single crystal blade are favorably shown.

Liu Xin Gang

Papers

Macrograin corrosion method for monocrystal high-temperature alloy casting containing Re and/or Ru