JPS60165367A - Treatment of plated steel wire - Google Patents

Abstract

PURPOSE:To obtain a plated steel wire alloyed in a homogenously diffused state toward the longitudinal direction of the wire, by heating the steel wire, to which copper plating and zinc plating are preliminarily applied, by passing the same through a hermetically closed heat insulating case filled with a substance having heat resistance and low in heat conductivity. CONSTITUTION:In alloying a steel wire 1, to which copper plating and zinc plating are preliminarily applied, under heating, the heating of said steel wire 1 is performed by passing said steel wire 1 through a longitudinally elongated hermetically closed heat insulating case 2 in the longitudinal direction during the treatment process thereof. This case 2 is hermetically closed except the outlet and inlet 3, 4 of the steel wire 1 provided to both ends thereof and filled with a substance having heat resistance and low in heat conductivity, for example, asbesto. Therefore, the temp. of the steel wire 1 passing through the case 2 for the purpose of heating is kept uniform and an alloyed wire having good homogeneity in the longitudinal direction is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field The present invention relates to a method of treating galvanized steel wire to obtain an alloy with excellent longitudinal homogeneity.

(b) Technical background As a positive plating method for steel wire for reinforcing rubber articles, there are two methods: depositing copper and zinc simultaneously in a cyan bath, and another method in which copper plating is applied to the steel wire, and then zinc plating is applied on top of the copper plating, followed by heating. Two methods have been used: copper and zinc are alloyed by diffusion.

Among these methods, the method using a cyanide bath is avoided due to pollution and environmental hygiene problems, and in recent years, the latter method using diffusion has become mainstream.

As a method for alloying copper and zinc by diffusion, a method using electrical heating has been adopted.

This method heats the steel wire using Joule heat generated by passing electricity through the wire, and is unique in that it can be heated in a short time.

However, when performing this electrical heating, the temperature of the wire is theoretically determined by the amount of electricity provided that its cross-sectional area and running speed are constant, and by keeping the amount of electricity constant, the temperature of the wire can be kept constant. It should be.

However, when the temperature of the wire was continuously measured using an infrared thermometer, it was found that the temperature of the wire fluctuated even if the amount of electricity was kept constant.

This is because the heat ω dissipated from the wire surface to the surroundings varies.

That is, this is due to the fact that the state of heat transfer from the wire surface to the surroundings changes due to changes in the flow state of the surrounding air.

(C) Disclosure of the Invention The present invention aims to provide a method for treating a plated steel wire in order to obtain a homogeneous alloy in a diffusion state in the length direction of the wire in positive plating using a diffusion method.

The present invention will be explained below based on the drawings.

That is, in this invention, when heating and alloying a pre-copper-plated and zinc-plated plated steel wire 1, the plated steel wire 1 is heated in a horizontally elongated sealed heat-insulating case 2 in the longitudinal direction during the treatment process. It is something that allows you to pass through and do what you do.

As shown in the figure, this sealed heat-insulating case 2 is sealed except for the entrances and exits 3 and 4 for the plated steel wire 1 at both ends, and inside the heat-insulating case 2 are materials that are heat resistant and have low thermal conductivity.
For example, it is filled with materials such as asbestos,
The plated steel wire 1 passing through the heat insulating case 2 for heating is kept at a uniform temperature during heating, and an alloy wire with good homogeneity in the length direction can be obtained.

In the figure, 5 is a power supply roller, and 6 is an AC power source.

In this invention, as described above, the plated steel wire is heated in a sealed heat-insulating case filled with a material such as asbestos that is heat resistant and has low thermal conductivity, so air fluctuations on the wire surface are minimized. In addition, because the wire is surrounded by a material with low thermal conductivity and good heat retention, the amount of heat dissipated from the wire surface is small, and therefore the fluctuation due to wire temperature is small.
This results in a homogeneous line.

The present invention will be explained below with reference to Examples.

EXAMPLE A steel wire having a diameter of 1.25 mm was subjected to positive plating under the conditions shown below.

Copper plating amount = 3.1 teeth/- Zinc plating amount: 1.9')/9 lines Speed: 5
0m/min Diffusion power (n: 3.0KW (1) When the surface temperature of the wire immediately after leaving the insulation case is measured continuously for one hour with an infrared thermometer, the temperature is 520.
The wire temperature was maintained between ~530°C, but when diffusion was carried out without a heat insulation case, the temperature of the wire varied by 40°C up and down to 480~520°C.

(2) 3 positive plated wires at 100m intervals
0 points were sampled, and X-ray diffraction revealed positive α phase and β
The ratio of phase intensities was determined.

When the insulating case of this invention was used, (strength of β phase/strength of α phase) was in the range of 0.15 to 0.25, whereas in the case without the insulating case, it was 0.20 to 0. .5
There was a large variation of 0.

It has been found that copper and zinc are more uniformly alloyed according to this invention.

X-ray diffraction was performed using Rigaku Denki RU100BL.
The test was carried out by shining α rays onto the sample at a secondary voltage of 37.5 KV and a current of 80 mA.

[Brief explanation of the drawing]

The drawing is a plan view of an apparatus for carrying out the processing method of the present invention. Substitute Patent Attorney Kazu 1) Akira

Claims (1)

[Claims] In the process of heating and alloying a steel wire that has been previously copper-plated and zinc-plated, the heating of the steel is performed using heat-resistant,
The steel wire is passed through a sealed heat-insulating case filled with a substance with low thermal conductivity, thereby keeping the temperature of the steel wire uniform and producing an alloy with excellent longitudinal homogeneity. Processing method for plated steel wire.