WO2018040536A1

WO2018040536A1 - Method for preparing composite hot-galvanized steel wire

Info

Publication number: WO2018040536A1
Application number: PCT/CN2017/076495
Authority: WO
Inventors: 月德; 吴平忠
Original assignee: 龙南县格林庭园用品有限公司
Priority date: 2016-08-30
Filing date: 2017-03-13
Publication date: 2018-03-08
Also published as: CN106119860A; CN106119860B

Abstract

Disclosed is a method for preparing a composite hot-galvanized steel wire, comprising the following steps: a high-speed carbon steel wire is drawn for the first time after water bath quenching, then the steel wire drawn for the first time is subjected to hot galvanizing with a hot galvanizing treating solution, and afterwards, the hot-galvanized steel wire is drawn for a second time so that a hot-galvanized steel wire (1) can be obtained; the resulting hot-galvanized steel wire (1) is first degreased and washed with water, and then is soaked with a silane coating agent solution and dried, and a silane coating (2) is generated on the surface of the hot-galvanized layer of the hot-galvanized steel wire (1); and the resulting hot-galvanized steel wire with the silane coating (2) is soaked in a passivation layer treating solution and roasted for 60-180 s at a temperature of 200-260ºC, so that a passivation layer (3) is formed on the surface of the silane coating (2) of the hot-galvanized steel wire, and thus the composite hot-galvanized steel wire can be obtained.

Description

Preparation method of composite hot-dip galvanized steel wire

Technical field

The invention belongs to the field of steel wires, and in particular relates to a method for preparing composite hot-dip galvanized steel wires.

Background technique

As we all know, there are two main types of galvanized steel wire produced and used in the field of metal material processing technology at home and abroad: one is cold-galvanized steel wire and the other is hot-dip galvanized steel wire.

Cold-galvanized steel wire, which is produced by drawing high-carbon steel wire. In production, the product is drawn, washed, degreased, rusted, washed, and cold-galvanized, then placed into trivalent chromic acid. The liquid (ie, a mixture of chromium trichloride and nitric acid, the volume ratio of the two is: chromium trichloride: nitric acid = 1: 0.8 to 1.2) is immersed for 30 to 60 seconds, and placed in the air at normal temperature and normal pressure. Heating 50-60 ° C until dry, the surface of the hot-dip galvanized steel wire quickly formed a dense trivalent free chromic acid film. The advantage is that the surface is smooth and bright, and the appearance is very good; but the disadvantages are also prominent, mainly in several aspects: 1) The galvanized layer is very thin only about 30-80 g/m2, which cannot be plated thick, if thickened The galvanized layer can be easily cracked and peeled off, which causes the steel wire product to rust easily under wet or acid-base conditions. It will start to rust in normal outdoor conditions for 1 to 3 months; 2) the galvanized layer is very brittle. If the steel wire product is used in a stressed state or is suddenly impacted by an external force, the galvanized layer is easily cracked or even peeled off. The cracking or peeling of the galvanized layer will directly contact the wire body with water or air, which directly accelerates the steel wire product. Rusting; the product produced by this cold galvanized steel wire has a very short service life, and can only be used for one production season in the outdoor; 3) The temperature required for heating and drying after treatment with trivalent chromic acid is strictly controlled at 50-60 °C, when the drying temperature is not well controlled and exceeds 70 ° C, the corrosion resistance of the chromic acid film will drop sharply.

Hot-dip galvanized steel wire is drawn by carbon steel high-strength wire. After drawing and hot-dip galvanizing, it is washed with water and triturated with trivalent chromic acid (ie, a mixture of chromium trichloride and nitric acid, two The volume ratio of the product is immersed in an aqueous solution of chromium trichloride: nitric acid = 1:0.8 to 1.2) for 30 to 60 seconds, and placed in the air at a normal temperature and a normal pressure for 50 to 60 ° C until dry, so that the surface of the hot-dip galvanized steel wire is rapidly formed. A dense trivalent free chromic acid film is formed. The advantage is that the galvanized layer can be plated very thick, and can reach about 200-500 g/m2, and the galvanized layer will not crack or peel off when the steel wire product is used in a stressed state or when it is suddenly impacted by an external force. The service life is very long; the disadvantages are: 1) During the hot dip galvanizing process of the steel wire, local zinc layer accumulation (commonly known as zinc tumor) is formed on the surface of the steel wire due to the vibration of the steel wire, the fluctuation of the zinc liquid surface, the surface scum in the plating pot, and the like. And the zinc ash formed by oxidation of some zinc oxides and other zinc compounds adheres to the surface of the steel wire zinc layer, so that the surface of the galvanized layer is not smooth, the surface is dull, there is no light brightness, and the surface effect is very poor; The products produced by hot-dip galvanized steel wire cannot be attracted to customers due to their appearance, and the sales effect is not good. 2) The temperature requirement for heating and drying after treatment with trivalent chromic acid is strictly controlled at 50-60 ° C, when the drying temperature is not well controlled. At 70 ° C, the corrosion resistance of the chromic acid film drops sharply.

In the prior art, it is often used to adjust the ratio of the elements of the steel itself or apply a single passivation layer on the surface of the steel wire to obtain good corrosion resistance, but there are still various deficiencies such as increasing cost, too complicated process or no effect of the passivation layer. Good, Limits the application of hot-dip galvanized steel wire.

Summary of the invention

The technical problem to be solved by the invention is to provide a preparation method of composite hot-dip galvanized steel wire, wherein the hot-dip galvanized steel wire prepared by the method has smooth surface and excellent corrosion resistance; the production process is streamlined, easy to produce, and has good application prospect. .

A method for preparing a composite hot-dip galvanized steel wire according to the present invention comprises the following steps:

(1) After quenching the carbon steel high line through the water bath, the first drawing is performed, and the first drawn steel wire is subjected to hot-dip galvanizing through a hot-dip galvanizing treatment liquid, and then the hot-dip galvanized steel wire is subjected to hot-dip galvanizing. The second drawing, that is, hot galvanized steel wire;

(2) The hot-dip galvanized steel wire obtained in the step (1) is first degreased and washed with water, then impregnated with a silane film solution, and dried to form a silane film on the surface of the hot-dip galvanized steel layer of the hot-dip galvanized steel wire;

(3) The hot-dip galvanized steel wire obtained in the step (2) is immersed in the passivation layer treatment liquid, and baked at 200-260 ° C for 60-180 s, so that a passivation layer is formed on the surface of the galvanized steel wire of the hot-dip galvanized steel wire, that is, composited Hot galvanized steel wire.

The water bath quenching condition in the step (1) is: water quenching liquid temperature: 90±5° C; tapping line temperature: 930±20° C; outlet water line temperature: 610±30° C.; immersion liquid length: 2.4-3.2 m; Wire immersion depth: 10 ~ 15mm.

The hot-dip galvanizing treatment liquid in the step (1) further comprises a plating agent; wherein the composition of the plating agent is: aluminum chloride 20-25 g/L, zinc chloride 31-35 g/L, potassium chloride 5-- 6 g / L, sodium fluoride 5-8 g / L, sodium bicarbonate 2-5 g / L.

The concentration of the silane coating agent solution in the step (2) is 1 to 2%, and the pH is 8 to 9.

The composition of the passivation layer treatment liquid in the step (3) is composed of 15.0 to 20.0 wt% of an epoxy resin, 2 to 5 wt% of hydrogen peroxide, 3 to 6 wt% of an organic acid, and water.

The organic acid is selected from one or more of citric acid, tartaric acid, malic acid, salicylic acid, and lactic acid.

Beneficial effect

(1) The invention adopts water bath quenching instead of lead quenching, the cost is significantly reduced, and the mechanical properties of the steel wire are stable;

(2) The silane film and the passivation layer are respectively formed on the surface of the steel wire after hot-dip galvanizing, thereby not only ensuring the appearance color requirement of the steel wire, effectively improving the corrosion resistance performance of the galvanized layer, and improving the service life of the galvanized layer; Avoid heavy metals, be more environmentally friendly and cost less;

(3) The hot-dip galvanized steel wire prepared by the invention has smooth surface and excellent corrosion resistance, and the service life can reach more than 15 years; (4) The production process of the invention is streamlined, easy to produce, and has good application prospect.

DRAWINGS

Figure 1 is a side view of the hot-dip galvanized steel wire of the present invention; wherein 1 is a hot-dip galvanized steel wire; 2 is a silane film layer; 3 is a passivation layer;

2 is a schematic view showing quenching of a water bath used in the present invention;

Figure 3 is a flow chart of the treatment of the steel wire of the present invention.

Detailed ways

The invention is further illustrated below in conjunction with specific embodiments. It is to be understood that the examples are not intended to limit the scope of the invention. In addition, it should be understood that various changes and modifications may be made by those skilled in the art in the form of the present invention.

Example 1

(1) After quenching the carbon steel high line through the water bath, the first drawing is performed, and the first drawn steel wire is subjected to hot-dip galvanizing through a hot-dip galvanizing treatment liquid, and then the hot-dip galvanized steel wire is subjected to hot-dip galvanizing. The second drawing, that is, hot galvanized steel wire; water quenching liquid temperature: 95 ° C; tapping line temperature: 950 ° C; water line temperature: 650 ° C; immersion liquid length: 2.4 m; steel wire immersion depth: 10 mm; hot plating The zinc treatment solution further contains a plating aid; wherein the composition of the plating agent is: aluminum chloride 20g/L, zinc chloride 31g/L, potassium chloride 5g/L, sodium fluoride 6g/L, sodium hydrogencarbonate 5g /L;

(2) The hot-dip galvanized steel wire obtained in the step (1) is first degreased and washed with water, and then impregnated with a solution of 2% silane film agent (LG-209, Changzhou Lianggong Environmental Protection Technology Co., Ltd.), and dried to make hot-dip galvanized steel wire. a surface of the hot-dip galvanized layer forms a silane film;

(3) The hot-dip galvanized steel wire obtained in the step (2) is immersed in a passivation layer treatment liquid (15.0 wt% epoxy resin, 2 wt% hydrogen peroxide, 3 wt% citric acid and water), and baked at 260 ° C. 60s, the passivation layer is formed on the surface of the galvanized steel wire of the hot-dip galvanized steel wire, that is, the composite hot-dip galvanized steel wire is obtained, and the test results of GB/T 6461-2002 are shown in Table 1.

Example 2

(1) After quenching the carbon steel high line through the water bath, the first drawing is performed, and the first drawn steel wire is subjected to hot-dip galvanizing through a hot-dip galvanizing treatment liquid, and then the hot-dip galvanized steel wire is subjected to hot-dip galvanizing. The second drawing, that is, hot galvanized steel wire; water quenching liquid temperature: 95 ° C; tapping line temperature: 950 ° C; water line temperature: 64 ° C; immersion liquid length: 3.2 m; steel wire immersion depth: 15 mm; hot plating The zinc treatment solution further contains a plating aid; wherein the composition of the plating agent is: aluminum chloride 25g/L, zinc chloride 35g/L, potassium chloride 6g/L, sodium fluoride 8g/L, sodium hydrogencarbonate 5g /L;

(3) The hot-dip galvanized steel wire obtained in the step (2) is immersed in a passivation layer treatment liquid (20.0 wt% epoxy resin, 5 wt% hydrogen peroxide, 6 wt% organic acid and water), and baked at 200 ° C. 180s, the passivation layer is formed on the surface of the galvanized steel wire of the hot-dip galvanized steel wire, that is, the composite hot-dip galvanized steel wire is obtained, and the test results of GB/T 6461-2002 are shown in Table 1.

The above description is only the preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Claims

A preparation method of composite hot-dip galvanized steel wire comprises the following steps:

(1) After quenching the carbon steel high line through the water bath, the first drawing is performed, and the first drawn steel wire is subjected to hot-dip galvanizing through a hot-dip galvanizing treatment liquid, and then the hot-dip galvanized steel wire is subjected to hot-dip galvanizing. The second drawing, that is, hot galvanized steel wire;

(2) The hot-dip galvanized steel wire obtained in the step (1) is first degreased and washed with water, then impregnated with a silane film solution, and dried to form a silane film on the surface of the hot-dip galvanized steel layer of the hot-dip galvanized steel wire;

(3) The hot-dip galvanized steel wire obtained in the step (2) is immersed in the passivation layer treatment liquid, and baked at 200-260 ° C for 60-180 s, so that a passivation layer is formed on the surface of the galvanized steel wire of the hot-dip galvanized steel wire, that is, composited Hot galvanized steel wire.
The method for preparing a composite hot-dip galvanized steel wire according to claim 1, wherein the water bath quenching condition in the step (1) is: water quenching liquid temperature: 90±5° C.; furnace temperature: 930 ±20 ° C; outlet water temperature: 610 ± 30 ° C; immersion liquid length: 2.4 ~ 3.2 m; steel wire immersion depth: 10 ~ 15 mm.
The method for preparing a composite hot-dip galvanized steel wire according to claim 1, wherein the hot-dip galvanizing treatment liquid in the step (1) further comprises a plating agent; wherein the composition of the plating agent is: chlorine Aluminum 20-25g / L, zinc chloride 31-35g / L, potassium chloride 5-6g / L, sodium fluoride 5-8g / L, sodium bicarbonate 2-5g / L.
The method for preparing a composite hot-dip galvanized steel wire according to claim 1, wherein the concentration of the silane coating agent solution in the step (2) is 1-2%, and the pH is 8-9.
The method for preparing a composite hot-dip galvanized steel wire according to claim 1, wherein the composition of the passivation layer treatment liquid in the step (3) is: from 15.0 to 20.0% by weight of the epoxy resin, 2 ～5 wt% hydrogen peroxide, 3-6 wt% organic acid and water.
The method for preparing a composite hot-dip galvanized steel wire according to claim 5, wherein the organic acid is one or more selected from the group consisting of citric acid, tartaric acid, malic acid, salicylic acid, and lactic acid.