Method for display dentrite morphology of gear steel continuous-casting billet

A display method and continuous casting slab technology, which is applied in the display field of gear steel continuous casting slab dendrite morphology, can solve the problems of low success rate, temperature sensitivity, long time, etc., and achieve fast erosion, easy operation, and erosion The effect of simple method

Active Publication Date: 2015-01-28
SHOUGANG CORPORATION
View PDF4 Cites 7 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The etchants of the picric acid series take a long time and are sensitive to temperature, and the success rate is not high

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

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for display dentrite morphology of gear steel continuous-casting billet
  • Method for display dentrite morphology of gear steel continuous-casting billet
  • Method for display dentrite morphology of gear steel continuous-casting billet

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] Dendritic erosion in continuously cast slabs for gear steel 20CrMnTiH. The sample is taken from the 20CrMnTiH continuous casting slab with a size of 200mm×200mm, and the sample is cut as figure 2 Dimensions shown, heat treated. The heat treatment process is as follows: the sample is heated to 930°C for 30 minutes, cooled to 680°C for 2 hours in the furnace, and then cooled to room temperature with the furnace. After heat treatment, the sample is milled off by 2 mm to avoid decarburization on the observation surface. After grinding and polishing, it was etched with 4% nitric acid alcohol. In order to compare with this method, this embodiment also uses picric acid series etchant to show its dendrite morphology. The morphology of dendrites at the edge, 1 / 4, and center of the slabs eroded by the two methods were observed by optical microscope.

[0032] image 3 The dendrite morphology of the continuous casting slab surface after picric acid attack is given. It can be...

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

The invention provides a method for displaying the dentrite morphology of a gear steel continuous-casting billet and belongs to the technical field of metallographic structure analysis and inspection. The method comprises the following steps: performing heat treatment on a gear steel continuous-casting billet sample, namely preserving the heat of the gear steel continuous-casting billet sample for 30-60 minutes at an austenitizing temperature in the range of Ac3 +50 to 100 DEG C, and then cooling along with a furnace to a range of perlitic transformation temperatures Ar 1-30 to 50 DEG C and preserving heat for 2 hours so that the austenite of the sample is completely decomposed, and finally, cooling along with the furnace to a room temperature; polishing the continuous-casting billet sample at the room temperature to remove iron oxide scale and a decarburized layer, and then performing grinding and polishing; immersing the ground and polished sample in 4% nital for 5 seconds, and then flushing the surface of the sample by use of clear water and drying; and at last, clearly observing the dentrite morphology of the eroded sample by use of an optical microscope. The method for displaying the dentrite morphology of the gear steel continuous-casting billet has the advantages that the dentrite morphology of the gear steel continuous-casting billet can be really and clearly displayed, and a primary dendrite spacing and a secondary dendrite spacing can be measured to provide basis for optimizing a gear steel continuous-casting process.

Description

technical field [0001] The invention belongs to the technical field of metallographic structure inspection and analysis, and in particular relates to a method for displaying dendrite morphology of continuous casting slabs of gear steel. Background technique [0002] Gear steel is the steel used for important parts of automobile gearboxes and engines, accounting for about one-third of the total steel used for vehicle parts. Due to the increasingly stringent requirements for automobile safety, energy saving, and environmental protection, the lightweight of automobiles has become a development trend, which reduces the weight of gears and improves their strength and toughness, and the load they bear is increasing. Therefore, automobile factories have higher and higher requirements on the quality of gear steel. [0003] Gear steel contains high alloying elements such as Mn and Cr. During continuous casting production, due to the separation and crystallization, dendrites and segr...

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
Patent Type & Authority Applications(China)
IPC IPC(8): G01N1/28G01N21/86
Inventor 柳洋波崔京玉佟倩王立峰陈京生丁宁马跃
Owner SHOUGANG CORPORATION
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