Production process of 90A high-strength corrosion-resistant AB-class hot-dip galvanized steel wire

Abstract

The invention relates to the technical field of steel rope production, in particular to a 90A high-strength corrosion-resistant AB-class hot-dip galvanized steel wire production process which comprises the following steps: 1) selecting a 90A steel wire rod; 2) heat treatment of the wire rod; 3) drawing a semi-finished product, wherein the tolerance range of the drawn semi-finished product is + / -0.02 mm, and the drawing production speed of the semi-finished product is 300-320m / min; (4) after the surface of the semi-finished product is cleaned, the semi-finished product enters a zinc pot to be galvanized, the zinc temperature is controlled within the range of 455 + / -5 DEG C, the hot galvanizing production speed is 9.81-13.8 m / min, and the zinc feeding amount is larger than 310 g / m < 2 >; (5) the plated semi-finished product is immersed in a low-concentration phosphating solution for micro-phosphating treatment, the total acidity of the phosphating solution is 50-60 Pt, the free acid is 3-4 Pt, the temperature is 50-60 DEG C, the immersion time is 1-3 min, and a layer of thin phosphating film is formed on the surface of the semi-finished product after micro-phosphating treatment; and (6) in the drawing process of the wire drawing machine, the temperature of the steel wire is controlled to be below 80 DEG C by a cooling system, 9-12 passes of drawing are conducted, the average drawing compression ratio is 14%-16%, and the center line of an outlet of a die box is adjusted to be consistent with the tangential direction of a winding drum. A layer of phosphating film is formed on the surface of the galvanized steel wire, and the functions of lubrication and corrosion resistance are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of steel rope production, and in particular to a production process of 90A high-strength, corrosion-resistant AB class hot-dip galvanized steel wire. Background Art

[0002] With the continuous development of cableways, steel wire ropes for cableways are developing towards high strength. With the increase in the specifications of cableway gondolas, the breaking tensile force required for cableway steel wire ropes is getting higher and higher. At the same time, the outer large-diameter steel wire of the cableway steel wire rope must meet ultra-high strength and have good corrosion resistance. The existing steel wire ropes for cableways can be produced to 2060 strength level with a diameter of less than 3mm. The pulling strength and zinc weight of steel wire ropes with a diameter greater than 3mm produced using the existing process do not meet the standards.

[0003] The existing patent 201510979946.1 discloses a galvanized steel wire production process, including the following steps: (a) hot-dip galvanizing treatment, feeding the steel wire into a galvanizing tank for surface galvanizing, controlling the amount of zinc to be 160-180g / m2, and subjecting the galvanized steel wire to surface high-temperature wiping treatment; (b) drawing treatment, using a wire drawing machine to draw the steel wire with a galvanized layer on the surface obtained in step (a) to a finished product diameter of 0.85mm-1.42mm, a partial compression rate of 19.5%-9.5%, and a total compression rate of no more than 68%, the die working taper of the wire drawing machine is 12°, the sizing zone height is about 0.1 times the finished product diameter, and the winding speed is no more than 300m / min. This patent cannot meet the production requirements of galvanized AB class high-strength large-diameter steel wire, the zinc weight cannot meet the AB class requirements of the national standard, and cannot produce steel wire with a diameter of more than 1.42mm, and the strength of ordinary carbon steel wire after drawing cannot reach 2160MPa. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a production process for 90A high-strength, corrosion-resistant AB class hot-dip galvanized steel wire, which adopts a micro-phosphating process to make the finished steel wire drawn after galvanizing have better corrosion resistance.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A production process of 90A high-strength corrosion-resistant AB class hot-dip galvanized steel wire, the specific steps are as follows:

[0007] 1) Select raw materials: choose 90A steel wire rod;

[0008] 2) Heat treatment: The wire rod heat treatment control line temperature is within the range of 950℃±5℃, the lead bath temperature is maintained within the range of 550±5℃, and the production speed is 5.0-6.8m / min; after heat treatment, the iron oxide scale on the surface of the wire rod is cleaned;

[0009] 3) Drawing of semi-finished products: drawing tolerance range of semi-finished products: ±0.02mm, semi-finished product drawing production speed: 300-320m / min;

[0010] 4) Hot-dip galvanizing: After the surface of the semi-finished product is cleaned, it is placed in a zinc pot for galvanizing. The zinc temperature is controlled within the range of 455±5℃, the hot-dip galvanizing production speed is 9.81-13.8m / min, and the zinc coating amount is >310g / m 2 ;

[0011] 5) Micro-phosphating: The semi-finished product after plating is immersed in a low-concentration phosphating solution for micro-phosphating treatment. The total acidity of the phosphating solution is 50-60Pt, the free acid is 3-4Pt, the temperature is 50-60℃, and the immersion time is 1-3min. After micro-phosphating plating, a thin phosphating film is formed on the surface of the semi-finished product;

[0012] 6) Finished product drawing: During the drawing process of the wire drawing machine, the cooling system controls the wire temperature below 80°C, 9-12 drawing passes, the average drawing compression rate is 14%-16%, and the center line of the mold box outlet is adjusted to be consistent with the tangent direction of the reel.

[0013] The chemical composition mass percentage requirements of the 90A steel wire rod described in step 1) are: C: 0.90%-0.93%, Si: 0.16%-0.19%, Mn: 0.38%-0.40%.

[0014] The mass of the thin phosphate film in step 5) is 2-3 g / m 2 .

[0015] In step 6), the cooling system uses air cooling and water cooling simultaneously.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The present invention utilizes high-quality 90A steel wire rod to produce high-strength, corrosion-resistant AB class galvanized steel wire. The low manganese, low silicon and high carbon characteristics of the 90A wire rod meet the technical conditions required for drawing high-strength galvanized steel wire, so that the stress during the steel wire drawing process is relatively small, which is conducive to smooth drawing. The steel wire produced with a diameter of less than 3.3 mm can meet the strength requirement of 2160 MPa, and the performance meets the national standard requirements.

[0018] 2. Micro-phosphating process is used in the production process to form a phosphating film on the surface of galvanized steel wire, which plays a lubricating role. At the same time, more wire drawing powder is introduced during the drawing process to promote the smooth drawing of the steel wire. The phosphating film on the surface of the steel wire after drawing also plays a corrosion-resistant role. It meets the high strength and corrosion-resistant requirements of steel wire for cableway wire ropes. DETAILED DESCRIPTION

[0019] It should be noted that, unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by technicians in the technical field of this application; the terms used in the specification of the application herein are only for the purpose of describing specific embodiments and are not intended to limit the present application. The reference to "embodiment" in this article means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0020] A production process of 90A high-strength corrosion-resistant AB class hot-dip galvanized steel wire, the specific steps are as follows:

[0021] 1) Select raw materials: choose 90A steel wire rod;

[0022] 2) Heat treatment: The wire rod heat treatment controls the line temperature within the range of 950℃±5℃, the lead bath temperature is maintained within the range of 550±5℃, and the production speed is 7.9-5.0m / min; after heat treatment, surface treatment is performed to clean the iron oxide scale on the surface of the wire rod;

[0023] 3) Drawing of semi-finished products: The tolerance range of semi-finished products is ±0.02mm, and the production speed of semi-finished products is 300-320m / min. During drawing, ensure that the air cooling and water cooling are normal, ensure that the mold is free of defects, and control the surface quality of the steel wire;

[0024] 4) Hot-dip galvanizing: After the surface of the semi-finished product is cleaned, it is placed in a zinc pot for galvanizing. The zinc temperature is controlled within the range of 455±5℃, the hot-dip galvanizing production speed is 9.81-13.8m / min, and the zinc coating amount is >310g / m 2 ;

[0025] 5) Micro-phosphating: The semi-finished product after plating is immersed in a low-concentration phosphating solution for micro-phosphating treatment. The total acidity of the phosphating solution is 50-60Pt, the free acid is 3-4Pt, the temperature is 50-60℃, and the immersion time is 1-3min. After micro-phosphating plating, a thin phosphating film is formed on the surface of the semi-finished product;

[0026] 6) Finished product drawing: During the drawing process of the wire drawing machine, the cooling system controls the wire temperature below 80°C, 9-12 drawing passes, the average drawing compression rate is 14%-16%, and the center line of the mold box outlet is adjusted to be consistent with the tangent direction of the reel.

[0027] The chemical composition mass percentage requirements of the 90A steel wire rod described in step 1) are: C: 0.90%-0.93%, Si: 0.16%-0.19%, Mn: 0.38%-0.40%.

[0028] The mass of the thin phosphate film in step 5) is 2-3 g / m 2 .

[0029] In step 6), the cooling system uses air cooling and water cooling simultaneously.

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0031] Embodiment 1:

[0032] The production process of 3.3mm diameter, AB class galvanized steel wire, the specific steps are as follows:

[0033] 1) Select raw materials: select 90A steel wire rod; the wire rod diameter is 10.0 mm; the chemical composition mass percentage requirements of 90A steel wire rod are: C: 0.90%, Si: 0.18%, Mn: 0.38%.

[0034] 2) Heat treatment: The heat treatment line temperature is within the range of 950℃±5℃, and the lead bath temperature is maintained within the range of 550±5℃. Ensure that there is no slag at the outlets before and after the lead bath, and no lead hanging on the surface of the steel wire. The production speed is 5.0m / min. After heat treatment, surface treatment is carried out to clean the iron oxide scale on the surface of the wire rod.

[0035] 3) Drawing of semi-finished products: The diameter of the drawn semi-finished products is 8.15mm, the tolerance range is ±0.02mm, the production speed is 300m / min, and the air cooling and water cooling are normal during drawing, the wire drawing powder is sufficient, the lubrication is good, the mold is defect-free, and the surface quality of the steel wire is controlled.

[0036] 4) Hot-dip galvanizing: After the surface of the semi-finished product is cleaned, it is placed in a zinc pot for galvanizing. The zinc temperature is controlled within the range of 455±5℃, the production speed is 9.81m / min, and the zinc coating amount is 460-500g / m 2 ;

[0037] 5) After plating, the semi-finished product is immersed in a low-concentration phosphating solution for micro-phosphating treatment. The total acidity of the phosphating solution is 55Pt, the free acid is 3.5Pt, the temperature is 55-60℃, and the immersion time is 2min. A thin phosphating film is formed on the surface of the semi-finished product after plating. The weight of the thin phosphating film is 2-3g / m 2 ;

[0038] 6) Finished product drawing: Air cooling and water cooling are used during the drawing process to control the wire drawing temperature below 80°C. Ten drawing passes are performed with an average drawing compression rate of 16.5%. The wire drawing powder is sufficient and lubrication is good. The center line of the die box outlet is adjusted to be consistent with the tangent direction of the reel.

[0039] The steel wire strength of this embodiment is 2160 MPa, the tolerance is ±0.02 mm, it is twisted 19 times, and bent 14 times.

[0040] Embodiment 2:

[0041] The production process of 2.8mm diameter, AB class galvanized steel wire, the specific steps are as follows:

[0042] 1) Select raw materials: select 90A steel wire rod; the wire rod diameter is 8.0 mm; the chemical composition mass percentage requirements of 90A steel wire rod are: C: 0.90%, Si: 0.18%, Mn: 0.38%.

[0043] 2) Heat treatment: The heat treatment line temperature is within the range of 950℃±5℃, and the lead bath temperature is maintained within the range of 550±5℃. Ensure that there is no slag at the outlets before and after the lead bath, and no lead hanging on the surface of the steel wire. The production speed is 6.8m / min. After heat treatment, surface treatment is carried out to clean the iron oxide scale on the surface of the wire rod.

[0044] 3) Drawing of semi-finished products: The diameter of the semi-finished products is 7.2mm, the tolerance range is ±0.02mm, and the production speed is 310m / min. During drawing, ensure that the air cooling and water cooling are normal, the wire drawing powder is sufficient, the lubrication is good, the mold is defect-free, and the surface quality of the steel wire is controlled.

[0045] 4) Hot-dip galvanizing: After the surface of the semi-finished product is cleaned, it is placed in a zinc pot for galvanizing. The zinc temperature is controlled within the range of 455±5℃, the production speed is 12.5m / min, and the zinc coating amount is 420-450g / m 2 ;

[0046] 5) After plating, the semi-finished product is immersed in a low-concentration phosphating solution for micro-phosphating treatment. The total acidity of the phosphating solution is 55Pt, the free acid is 3.5Pt, the temperature is 50-55℃, and the immersion time is 2min. A thin phosphating film is formed on the surface of the semi-finished product after plating. The weight of the thin phosphating film is 2-3g / m 2 ;

[0047] 6) Finished product drawing: Air cooling and water cooling are used during the drawing process to control the wire drawing temperature below 80°C. Ten drawing passes are performed with an average drawing compression rate of 17.21%. The wire drawing powder is sufficient and lubrication is good. The center line of the die box outlet is adjusted to be consistent with the tangent direction of the reel.

[0048] The steel wire strength of this embodiment is 2160 MPa, the tolerance is ±0.02 mm, it is twisted 20 times, and bent 13 times.

[0049] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and basic spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A 90A high-strength, corrosion-resistant, AB-class hot-dip galvanized steel wire production process, characterized in that: The specific steps are as follows: 1) Select raw materials: choose 90A steel wire rod; 2) Heat treatment: The wire rod heat treatment control line temperature is within the range of 950℃±5℃, the lead bath temperature is maintained within the range of 550±5℃, and the production speed is 5.0-6.8m / min; after heat treatment, the iron oxide scale on the surface of the wire rod is cleaned; 3) Drawing of semi-finished products: drawing tolerance range of semi-finished products: ±0.02mm, semi-finished product drawing production speed: 300-320m / min; 4) Hot-dip galvanizing: After the surface of the semi-finished product is cleaned, it is placed in a zinc pot for galvanizing. The zinc temperature is controlled within the range of 455±5℃, the hot-dip galvanizing production speed is 9.81-13.8m / min, and the zinc coating amount is >310g / m 2 ; 5) Micro-phosphating: The semi-finished product after plating is immersed in a low-concentration phosphating solution for micro-phosphating treatment. The total acidity of the phosphating solution is 50-60Pt, the free acid is 3-4Pt, the temperature is 50-60℃, and the immersion time is 1-3min. After micro-phosphating plating, a thin phosphating film is formed on the surface of the semi-finished product; 6) Finished product drawing: During the drawing process of the wire drawing machine, the cooling system controls the wire temperature below 80°C, 9-12 drawing passes, the average drawing compression rate is 14%-16%, and the center line of the mold box outlet is adjusted to be consistent with the tangent direction of the reel.

2. The production process of 90A high-strength corrosion-resistant AB class hot-dip galvanized steel wire according to claim 1 is characterized in that: The chemical composition mass percentage requirements of the 90A steel wire rod described in step 1) are: C: 0.90%-0.93%, Si: 0.16%-0.19%, Mn: 0.38%-0.40%.

3. The production process of 90A high-strength corrosion-resistant AB class hot-dip galvanized steel wire according to claim 1 is characterized in that: The mass of the thin phosphate film in step 5) is 2-3 g / m 2 .

4. The production process of 90A high-strength corrosion-resistant AB class hot-dip galvanized steel wire according to claim 1 is characterized in that: In step 6), the cooling system uses air cooling and water cooling simultaneously.