WO2023159531A1

WO2023159531A1 - Bead wire and manufacturing method

Info

Publication number: WO2023159531A1
Application number: PCT/CN2022/078135
Authority: WO
Inventors: 姚海东; 周志嵩
Original assignee: 江苏兴达钢帘线股份有限公司
Priority date: 2022-02-24
Filing date: 2022-02-28
Publication date: 2023-08-31
Also published as: CN114589952A

Abstract

A bead wire (10) and a manufacturing method. The carbon content of a base surface layer (12) of the bead wire (10) is 1.01-1.50 times the carbon content of a base. The manufacturing method comprises: S1, processing a wire to obtain a preset wire diameter; S2, tempering the wire; S3, carrying out surface carburization treatment on the wire, so that the carbon content of the base surface layer (12) of the wire is 1.01-1.50 times of the carbon content of the base; and S4, after the wire is cleaned, applying a plating (11) to obtain a finished bead wire (10). Step S3 may be performed before or after S2. The bead wire (10) has a good adhesive force.

Description

A kind of bead wire and its manufacturing method

technical field

The invention relates to the technical field of rubber products, in particular to a bead wire and a manufacturing method.

Background technique

A radial tire is generally composed of a crown, a sidewall, and a bead. The bead is tightened on the rim, providing a support point for the tire carcass, and carrying the outward expansion pressure of the carcass and the lateral force of the tire during turning. The bead is composed of a bead ring and a chafer, and the steel wire used to make the bead ring is the bead wire. Bead wires are required to have characteristics such as high strength and excellent bonding performance. Bead wires have circular cross-sections, rectangular cross-sections, polygonal cross-sections, etc., among which bead wires with circular cross-sections are more common. The surface of the bead wire generally needs to be covered with tin bronze plating, and also covered with brass plating or zinc layer, etc., to improve the adhesion between the bead wire and rubber. The bead wire is also coated with a resin coating on the surface to further improve the adhesion between the bead wire and the rubber. The adhesion between bead wire and rubber depends not only on the wire, but also on the rubber formula. When the rubber formula is constant, the adhesion is usually ensured and improved by controlling the surface condition of the bead wire, the composition of the coating, the thickness of the coating, and the composition of the coating. However, high-performance tires still require bead wires with higher adhesion properties.

Contents of the invention

An object of the present invention is to provide a bead wire with good adhesive performance and a manufacturing method.

To achieve the above object, the present invention discloses a bead wire, the carbon content of the surface layer of the matrix of the bead steel wire is 1.01 to 1.50 times the carbon content of the matrix.

The carbon content of the matrix surface layer of the bead steel wire is distributed in a gradient decreasing manner from outside to inside.

Wherein, the base surface layer of the bead wire refers to the interval from the surface of the wire to a depth of about 0.1 μm below the plating or coating. Below the surface layer of the matrix is the inner layer of the matrix. The matrix includes the surface layer of the matrix and the inner layer of the matrix. Since the proportion of the surface layer of the matrix to the matrix is very small, the carbon content of the matrix is approximately equal to the carbon content of the inner layer of the matrix.

The carbon content of the surface layer of the matrix of the bead steel wire is lower than 1.01 times of the carbon content of the matrix, and the influence on the bonding performance of the steel wire and rubber is not obvious. The carbon content of the surface layer of the matrix of the bead steel wire is higher than 1.50 times of the carbon content of the matrix, which will affect the combination of the coating and the steel wire matrix, which is not conducive to the adhesion of the steel wire to the rubber.

As a preferred solution, the carbon content of the matrix material of the bead wire is 0.60-1.00 wt%. If the carbon content of the matrix material is lower than 0.60%, the effect of increasing the carbon content of the surface layer of the matrix will be weakened, and at the same time, the strength of the bead steel wire will be low. If the carbon content of the base material is higher than 1.00%, the plasticity of the bead wire will be deteriorated.

As a preferred solution, the surface of the base body of the bead wire is covered with a copper alloy plating layer. Copper alloy plating includes tin bronze plating, brass plating, and the like.

As a preferred solution, the thickness of the copper alloy coating is 0.05-0.20 μm. If the thickness of the coating is less than 0.05 μm, the effect of the coating on enhancing the adhesion between the steel wire and the rubber will be weakened. If the thickness of the coating is higher than 0.20 μm, it will hinder the reaction between the carbon element on the surface of the substrate and the rubber.

The present invention also discloses a manufacturing method for manufacturing the bead wire, comprising:

S1: processing the steel wire to obtain a predetermined wire diameter;

S2: tempering is carried out to steel wire;

S3: Carry out surface carburization treatment to steel wire, make the carbon content of the matrix surface layer of steel wire be 1.01～1.50 times of the carbon content of matrix;

S4: after the steel wire is cleaned, the coating is coated to obtain the finished bead steel wire;

The step of S3 can also be performed before S2.

As a preferred solution, the surface carburization treatment in step S3 is electrochemical pickling. Electrochemical pickling reacts the iron on the surface of the steel wire with acid to wash away the iron on the surface of the steel wire, so that the carbon content of the surface of the steel wire is higher than that of the steel wire matrix.

As a preferred solution, the surface carburizing treatment in step S3 is surface carburizing treatment, and the temperature of the surface carburizing treatment is not higher than 250°C. The temperature of the surface carburizing treatment is higher than 250°C, which will lead to a significant decrease in the strength of the bead wire.

Beneficial effects of the present invention: the bead wire of the present invention has higher adhesion through surface carburization treatment.

Description of drawings

Fig. 1 is a schematic cross-sectional view of a bead wire of the present invention;

Among them: 10-bead wire, 11-plating or coating, 12-substrate surface layer, 13-substrate inner layer.

Detailed ways

The present invention will be further described below in conjunction with specific embodiments. The following examples are only used to illustrate the technical solution of the present invention more clearly, but not to limit the protection scope of the present invention.

The inventors found that a certain amount of carbon enrichment in the surface layer of the bead steel wire matrix can significantly improve the adhesion between the bead steel wire and rubber. Based on this, the present invention provides a bead wire.

As shown in FIG. 1 , a bead wire 10 includes a matrix, and the matrix includes a matrix inner layer 13 of the bead wire and a matrix surface layer 12 of the bead wire.

The depth of the substrate surface layer 12 is approximately 0.1 μm. Since the area of the surface layer 12 of the matrix accounts for a small proportion of the matrix, the carbon content of the matrix is approximately equal to the carbon content of the inner layer 13 of the matrix.

Here, the carbon content of the base surface layer 12 of the bead wire is 1.01 to 1.50 times the carbon content of the base.

The carbon content of the matrix surface layer 12 of the bead wire is distributed in a gradient decreasing manner from outside to inside.

The carbon content of the base material of the bead wire is 0.60 to 1.00 wt%.

As shown in FIG. 1 , the base surface of the bead wire is also covered with a plating or coating 11 , for example a copper alloy plating. The thickness of the copper alloy plating layer is 0.05-0.20 μm.

The carbon content of the surface layer 12 of the bead wire matrix can be increased by carburizing the steel wire surface. Carburizing treatment includes but not limited to electrochemical pickling, low temperature surface carburizing treatment and other methods.

Example 1-3

Examples 1-3 are 1.65mm bead wires. The manufacturing process is as follows: drawing a 5.50mm wire rod with a carbon content of 0.72wt% to 1.65mm, and then tempering in an intermediate frequency furnace with 20KW power, and then using 50A Electrolytic sulfuric acid washing with current of /dm ² carries out carburization treatment on the surface of the steel wire matrix, and finally tin bronze coating is plated. The carbon content of the matrix of the bead steel wire is 0.72wt%. By adjusting different electrolytic sulfuric acid washing time, samples with different carbon content of the surface layer of the matrix are obtained. Wherein the carbon content of the matrix surface layer of embodiment 1 is 0.85wt%, and the carbon content of matrix surface layer is 1.18 times of the carbon content of matrix; The carbon content of the matrix surface layer of embodiment 2 is 0.75wt%, and the carbon content of matrix surface layer is matrix 1.04 times of the content of the matrix; the carbon content of the surface layer of the matrix in Example 3 is 1.05wt%, and the carbon content of the surface layer of the matrix is 1.46 times of the content of the matrix.

For the 1.65 mm bead wire of Comparative Example 1 of the same specification, the carbon content of both the surface layer of the matrix and the matrix is 0.72 wt%. Embodiment 1-3 and the comparative example of prior art are carried out comparative test, and test result is shown in Table 1.

Table 1

It can be seen from Table 1 that compared with Comparative Example 1, the present Examples 1-3 have higher adhesive force.

Example 4

Example 4 is a 2.00mm bead wire. The manufacturing process is to draw a 5.50mm wire rod with a carbon content of 0.82wt% to 2.00mm, then carry out surface carburizing treatment at 150°C, and then use 25KW power in an intermediate frequency furnace Tempered and finished with tin bronze plating. The carbon content of the matrix of the bead wire is 0.82wt%, the carbon content of the surface layer of the matrix is 1.15wt%, and the carbon content of the surface layer of the matrix is 1.40 times the carbon content of the matrix.

For the 2.00 mm bead wire of Comparative Example 2 of the same specification, the carbon content of both the surface layer of the matrix and the matrix is 0.82 wt%. The present embodiment and the comparative example of the prior art are compared and tested, and the test results are shown in Table 2.

Table 2

It can be seen from Table 2 that compared with Comparative Example 2, Example 4 has higher adhesive force.

It can be seen from the above examples that the bead wire of the present invention has higher adhesion through surface carburization treatment.

The bead wire of the present invention can be applied to rubber products, including tires, rubber hoses and the like.

The present invention has been disclosed above with preferred embodiments, but it is not intended to limit the present invention. All technical solutions obtained by adopting equivalent replacement or equivalent transformation schemes fall within the protection scope of the present invention.

Claims

A bead wire, characterized in that the carbon content of the surface layer of the matrix of the bead steel wire is 1.01 to 1.50 times the carbon content of the matrix.
The bead wire according to claim 1, characterized in that the carbon content of the surface layer of the matrix of the bead wire is distributed in a gradient decreasing manner from outside to inside.
The bead wire according to claim 1 or 2, characterized in that the carbon content of the base material of the bead wire is 0.60 to 1.00 wt%.
The bead wire according to any one of claims 1-3, characterized in that, the surface of the base body of the bead wire is covered with a copper alloy plating layer.
The bead wire according to claim 4, characterized in that the thickness of the copper alloy plating layer is 0.05-0.20 μm.
A method of manufacturing the bead wire according to any one of claims 1 to 3, comprising:

S1: processing the steel wire to obtain a predetermined wire diameter;

S2: tempering is carried out to steel wire;

S3: Carry out surface carburization treatment to steel wire, make the carbon content of the matrix surface layer of steel wire be 1.01～1.50 times of the carbon content of matrix;

S4: after the steel wire is cleaned, the coating is coated to obtain the finished bead steel wire;

The step of S3 can also be performed before S2.
The method for manufacturing a bead wire according to claim 6, characterized in that the surface carburization treatment is electrochemical pickling.
The manufacturing method of bead wire according to claim 6, characterized in that the surface carburizing treatment is surface carburizing treatment, and the temperature of the surface carburizing treatment is not higher than 250°C.