Method for representing center segregation of high-carbon steel wire rod

A high-carbon steel and wire rod technology, applied in material inspection products, testing metals, etc., can solve problems such as the inability to accurately characterize the quality of different materials, the inability to meet the needs of slight segregation characterization, and the inability to quantitatively give segregation ratios.

Inactive Publication Date: 2013-02-06
INST OF RES OF IRON & STEEL JIANGSU PROVINCE
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although this method is simple and intuitive, it cannot quantify the segregation ratio, and can only vaguely determine a segregation level, and the result is highly volatile
With the improvement of iron and steel metallurgy, central segregati

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] Using this method to characterize the central carbon segregation of Φ5.5mm 82 grade cord steel in a domestic factory

[0026] Cord steel is used in the manufacture of steel cords for automobile tires. The steel cord is made of many small steel wires, and the diameter of the steel wire is Φ0.15~0.38mm. These steel wires are drawn from Φ5.5mm cord steel wire rods through multiple passes. Serious wire rod segregation will cause wire breakage during the drawing process, affecting production efficiency. Characterizing the segregation degree of cord steel can evaluate the quality of cord steel products and provide guidance for procurement and production. During the processing of cord steel in a domestic factory, cup-cone fractures occurred many times during the plying process due to central segregation. Utilize described method of the present invention, characterize this 82 grade cord steel central segregation, concrete steps and method are as follows:

[0027] (1) Select...

Embodiment 2

[0034] Characterization of central carbon segregation in Nippon Steel 82 grade cord steel by this method

[0035] The sample is taken from a wire rod imported from Japan's Nippon Steel by a domestic steel cord manufacturer, with a specification of Φ5.5mm. In the process of manufacturing steel cords, the wire rod has a very low rate of strand breakage, and its performance is very satisfactory. Utilize described method of the present invention, characterize its central carbon segregation, concrete steps and method are as follows:

[0036] (1) The sample is Nippon Steel 82 grade cord steel with a carbon content of 0.82wt% and a structure of 94% sorbite+6% pearlite;

[0037] (2) Straighten the wire rod first, then use wire cutting to take a needle-shaped sample from the center of the wire rod and 1 / 2 of the radius, the sample size is 0.5cm×0.5cm×1.5cm, and then use sandpaper to grind it into a Needle-point shape, further prepared by electrolytic polishing method into a sample th...

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Abstract

The invention relates to a method for representing center segregation of a high-carbon steel wire rod. The method includes differentiating a cementite phase and a ferrite phase at first; measuring carbon contents of different positions of the high-carbon steel wire rod by a 3DAP (three-dimensional atom probe); and comparing the carbon contents so that the center segregation of the high-carbon steel wire rod can be effectively evaluated. The different positions of the high-carbon steel wire rod at least include a severe segregation position and a segregation-free position. Compared with the traditional method, the method has the advantages that segregation of carbon of the high-carbon steel hot-rolled wire rod which is pearlite can be quantitatively and accurately evaluated, and the method is particularly applicable to evaluating steel with high requirement on the center segregation, such as tire cord steel with the carbon content ranging from 0.72% to 0.92%, cutting steel wires with the carbon contents ranging from 0.72% to 0.92%, galvanized steel wires with the carbon contents ranging from 0.82% to 0.87% for bridges, steel strands with the carbon contents ranging from 0.82% to 0.87% for bridges, and the like.

Description

technical field [0001] The invention relates to a method for accurately evaluating the central segregation of hot-rolled high-carbon steel wire rods, which is particularly suitable for evaluating steel types with high requirements for central segregation, and belongs to the field of metal analysis and characterization. Background technique [0002] At present, the method of evaluating the central segregation of hot-rolled wire rods with a carbon content higher than 0.60wt% is generally to compare the macroscopic appearance after corrosion with the standard atlas. This method is greatly affected by the sample preparation personnel, sample preparation level, and corrosion degree. Different personnel prepare samples, and the results may deviate by 0.5 to 1 level; even if the same person prepares samples under the same conditions, the degree of corrosion is different, and the rating results will also differ by 0.5 to 1 level. Although this method is simple and intuitive, it can...

Claims

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Application Information

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IPC IPC(8): G01N33/20
Inventor 王世芳王雷麻晗
Owner INST OF RES OF IRON & STEEL JIANGSU PROVINCE
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