Rating method for pearlitic steel microstructure subject to hydrogen damage

A microstructure, pearlitic steel technology, applied in optical testing of flaws/defects, preparation of samples for testing, etc., can solve the problems of not providing accurate assessment of hydrogen damage fracture risk, accurate classification without hydrogen damage, etc., to achieve reliable The effect of inspection and evaluation, easy operation and simple principle

Inactive Publication Date: 2014-08-06
STATE GRID CORP OF CHINA +2
View PDF8 Cites 5 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At present, the traditional non-destructive testing methods are used to detect the hydrogen damage of metal materials. The defect of these methods is that the degree of hydrogen damage is not accurate

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0014] (1) Ask for the commissioned pearlitic steel hydrogen damage microstructure rating of the thermal power plant boiler water wall pearlitic steel wall material cross-section sample, equipped with a commercially available S1M-FF02-125B type grinder, commercially available LAP-1X type A metallographic sample polishing machine, a commercially available 200-1000 magnification LECO-500 metallographic microscope, consumables 200-1000 mesh sandpaper, and alcohol solution with 3-5% nitric acid content;

[0015] (2), use the grinder prepared in step (1) to grind the test surface of the sample taken in step (1) until the test surface of the sample is smooth to the naked eye;

[0016] (3), use the sandpaper prepared in step (1) to grind the inspection surface of the sample that has been ground flat through step (2), and grind until the particle size of the inspection surface of the sample reaches 700-900 mesh;

[0017] (4), using the polishing machine prepared in step (1) to polish ...

Embodiment 2

[0022] (1) Ask for the pearlitic steel wall section sample of the water-cooled wall of the thermal power plant boiler commissioned to grade the hydrogen damage microstructure of the pearlite steel, equipped with a commercially available S1M-FF02-125B grinder and a commercially available HB400 electrolytic polishing One machine, one commercially available LECO-500 metallurgical microscope with magnification of 200-1000, consumables 200-1000 mesh sandpaper, alcohol solution with 3-5% nitric acid content;

[0023] Steps (2)~(3) are the same as in Example 1;

[0024] (4), use the electropolishing machine prepared by step (1) to polish the test surface of the sample ground through step (3);

[0025] Steps (5)-(7) are the same as in Example 1.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

This invention introduces a rating method for a pearlitic steel microstructure subject to hydrogen damage. The rating method comprises the following steps: (1) asking for a wall material sample, and configuring a grinding machine, a polishing machine and a metallographic microscope; (2) using the grinding machine to grind till a smooth surface is achieved; (3) using sandpaper to grind till 700-900 meshes are obtained; (4) using the polishing machine or an electrolytic polishing tank for polishing; (5) smearing with an alcoholic solution containing 3-5% nitric acid; (6) using the metallographic microscope with the amplification factor of 200-1000 to observe, and photographing; (7) in the light of metal material hydrogen damage standard diagram, noting the hydrogen damage level of the microstructure. The rating method can accurately evaluate the hydrogen damage degree of the water cooled wall of a boiler in a thermal power plant, is simple in principle, convenient in operation and accurate in test, and thus is an effective method for quickly and reliably evaluating hydrogen damage to pearlitic steel-like metallic materials.

Description

technical field [0001] The invention belongs to the technical field of metallurgical inspection, and in particular relates to a hydrogen-damaged microstructure grading method of pearlitic steel, a metal material. Background technique [0002] In the field of metallurgy, especially pearlitic steel, that is, No. 20 steel, is widely used in the water wall of boilers in thermal power plants. During long-term high-temperature use of this No. 20 steel, when it encounters hydrogen protons or hydrogen media in hydrogen media or other corrosive substances, the pearlite in its tissue will decarburize, that is, carburization in the tissue Cementite reacts with hydrogen or protons. During the reaction process, the cementite form gradually disappears, and the mechanical properties of the material decrease accordingly. The products will also gather in the cementite reaction area, causing intergranular voids to appear in this area. Under the action of operating temperature and pressure, t...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): G01N1/32G01N21/88
Inventor 龙会国谢国胜龙毅李登科
Owner STATE GRID CORP OF CHINA
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap