Stainless steel wire for reinforcing layer of polytetrafluoroethylene hose and method for manufacturing the same

Abstract

The present application relates to a kind of polytetrafluoroethylene hose reinforcing layer with stainless steel wire and its preparation method, comprising the following steps S1: selecting solid solution pickling HRAP's stainless steel rod, the chemical composition in its composition C: 0.06%~0.08%;S2: skin film processing;S3: rough extraction;S4: annealing;S5: fine extraction;S6: annealing;S7: fine drawing;S8: multiple tempering, stainless steel wire reciprocating tempering after fine drawing.The preparation method of the present application starts from the chemical composition and processing technology of stainless steel wire raw material, ensures that the tensile strength of stainless steel wire strength requirement is not less than 2300Mpa, and the knot tensile strength of steel wire should be not less than 1300Mpa, while the strength of packaging steel wire is improved, the possible strength loss in weaving or winding of customer end is reduced, and the comprehensive performance of steel wire reinforcing layer is guaranteed.

Description

Technical Field

[0001] This invention belongs to the field of metal wire production and processing technology, specifically relating to a stainless steel wire for the reinforcing layer of polytetrafluoroethylene hoses and its preparation method. Background Technology

[0002] Compared to traditional rubber hose assemblies, PTFE hose assemblies have higher performance requirements, including lighter weight, higher pressure resistance, aging resistance, corrosion resistance, wider operating temperature range, and longer service life. They are widely used in aerospace vehicles, oil drilling, automobiles, and other special applications. Stainless steel wire is commonly used as the reinforcing layer in PTFE hose assemblies, and the stainless steel wire is arranged in a braided or wound form on the inner surface of the PTFE hose.

[0003] In practical applications, for aviation hoses, which need to withstand higher temperatures and impacts, the stainless steel wire used for the reinforcing layer of PTFE hoses requires a tensile strength of not less than 2200 MPa and a knotted tensile strength of not less than 1280 MPa. The performance of stainless steel wire produced using traditional manufacturing processes cannot meet these requirements. Summary of the Invention

[0004] To address the aforementioned problems, the present invention aims to provide a method for preparing stainless steel wire for the reinforcing layer of polytetrafluoroethylene (PTFE) hoses. This method addresses both the chemical composition of the stainless steel wire raw material and the processing technology, ensuring that the tensile strength of the stainless steel wire is not less than 2200 MPa and the knotted tensile strength is not less than 1280 MPa.

[0005] The technical solution adopted by this invention to solve the above problems is: a method for preparing stainless steel wire for the reinforcing layer of polytetrafluoroethylene (PTFE) hoses, comprising the following steps:

[0006] S1: Select stainless steel wire rods with solution pickling and HRAP treatment. The chemical composition is as follows: C: 0.06%~0.08%, Si≤1.00%, Mn≤2.00%, P≤0.045%, S≤0.03%, Ni: 8.0%-9.0%, Cr: 18.0%~19.0%, N<0.10%, with the balance being Fe;

[0007] S2: Coating treatment, immerse the stainless steel wire rod from step S1 in a coating treatment tank containing coating treatment solution, and then remove and dry it.

[0008] S3: Coarse drawing. The stainless steel wire rod after S2 coating is drawn through a straight-line wire drawing machine in multiple passes to obtain semi-finished stainless steel wire. The wire is then washed with water. Lubricating powder is used in the wire drawing process. The temperature of the mold cooling water is 25~35℃.

[0009] S4: annealing, the semi-finished stainless steel wire obtained in the step S3 is firstly acid washed through an electrolytic acid washing tank, then solid solution treated through a tube type continuous annealing furnace, and finally cooled through a water cooling tank by a passive wire feeding device;

[0010] S5: fine drawing, the annealed steel wire in the step S4 is sequentially drawn through a skinning tank, an oven and a straight type wire drawing machine by a wire feeding rack, and then washed with water, wherein a lubricating powder is used in the drawing, and the cooling water temperature of the die box is 25-35℃;

[0011] S6: annealing, the fine drawn stainless steel wire in the step S5 is firstly acid washed through an electrolytic acid tank, then solid solution treated through a tube type continuous annealing furnace, and finally cooled through a water cooling tank by a passive wire feeding device;

[0012] S7: fine drawing, the annealed stainless steel wire in the step S6 is drawn through a water tank drawing machine;

[0013] S8: multiple tempering, the fine drawn stainless steel wire in the step S7 is reciprocating tempered through a tube type furnace.

[0014] Preferably, the skinning treatment liquid in the step S2 is an aqueous solution of a mixture of potassium sulfate and sodium sulfate, the concentration of the skinning treatment liquid is 15-21wt%, the temperature of the skinning treatment liquid is 70-90℃, the soaking time is 20-30min, the drying temperature is 180-230℃, and the drying time is 100-150min.

[0015] Preferably, the total reduction in the step S3 is controlled to be 70-90%, and the lubricating powder used in the last pass is sodium stearate lubricating powder, and the lubricating powder used in the other passes is calcium stearate lubricating powder.

[0016] Preferably, in the steps S4 and S6, the stainless steel wire is used as an anode, a lead plate is used as a cathode, and a dilute sulfuric acid solution is used as an electrolyte.

[0017] Preferably, in the steps S4 and S6, the solid solution treatment temperature is 1050-1120℃, the protective gas is N2+H2, and the heat treatment speed satisfies the formula: wire diameter D x heat treatment speed V = 20-25 (mm x m) / min, wherein the unit of the wire diameter is mm, and the unit of the heat treatment speed is m / min.

[0018] Preferably, in the step S5, the total reduction is controlled to be 70-90%, and the lubricating powder used is TF46.

[0019] Preferably, in the step S7, the total reduction is 91-94%, the lubricating agent is TF486, and the pass deformation is 13-15%.

[0020] Preferably, in the step S8, the tempering times are 3-5, and the tempering temperature is 180-220℃.

[0021] A kind of polytetrafluoroethylene hose reinforcing layer stainless steel wire, using the preparation method of above-mentioned polytetrafluoroethylene hose reinforcing layer stainless steel wire is prepared.

[0022] Compared with prior art, the advantages of the present application are that:

[0023] The tensile strength of the stainless steel wire prepared by the preparation method of the present application is stabilized at 2300Mpa or more, and the knot tensile strength is stabilized at 1300Mpa or more, which improves the strength of the packaged steel wire, reduces the possible strength loss in braiding or winding at the customer end, and ensures the comprehensive performance of the steel wire reinforcing layer. DETAILED DESCRIPTION

[0024] The present application will be further described in detail below in combination with examples. Example 1

[0025] S1: Select φ5.5mm solid solution pickling HRAP stainless steel wire rod, and the chemical composition is: C: 0.068%, Si: 0.37%, Mn: 1.23%, P: 0.04%, S: 0.02%, Cr: 18.23%, Ni: 8.06%, N: 0.056%, and the balance is Fe.

[0026] S2: Skin treatment, immerse the selected φ5.5mm stainless steel wire rod in S1 in 80℃ skin treatment liquid for 30min, the skin treatment liquid is an aqueous solution of potassium sulfate and sodium sulfate, the concentration is 18wt%, after soaking, take out and dry in a warm air furnace, the drying temperature is 200℃, the drying time is 120min, and the steel wire is used after the surface is dried.

[0027] S3: Rough drawing, pass the φ5.5mm stainless steel wire rod after S2 skin treatment through the straight-in drawing machine through the wire rack to obtain semi-finished stainless steel wire by 8 passes of drawing treatment, the drawing specification of each pass is 5.5mm-4.5mm-3.74mm-3.15mm-2.69mm-2.33mm-2.11mm-1.94mm-1.8mm, except that sodium stearate lubricating powder NL305 (produced by Jiangyin Taifeng Chemical Technology Co., Ltd.) is used in the last pass, calcium stearate lubricating powder GB205 (produced by Jiangyin Taifeng Chemical Technology Co., Ltd.) is used in other passes, and then the steel wire is washed to remove the lubricating powder, wherein the mold box cooling water temperature is 30℃, the drawing steel wire specification is φ1.8mm, and the total area reduction of the wire rod drawing is 89.3%.

[0028] S4: annealing, the semi-finished stainless steel wire is first passed through an electrolytic pickling tank (in the electrolytic pickling tank, the stainless steel wire serves as an anode, a lead plate serves as a cathode, and a dilute sulfuric acid solution serves as an electrolyte, the residual lubricating powder on the surface of the steel wire is removed through electrolytic pickling and water rinsing), then is passed through a tube type continuous annealing furnace for solid solution treatment, and then is cooled through a water cooling tank, wherein the solid solution treatment temperature is 1050°C, the protective gas is N2+H2, and the heat treatment production speed DV is controlled to be 20 (mm*m) / min.

[0029] S5: fine drawing, the stainless steel wire after the annealing in S4 is sequentially passed through a skin pass tank, an oven, and a straight-line drawing machine for online 10-pass drawing, the first-pass reduction is controlled to be 25%, and then is reduced by pass, the lubricating powder is TF46, and then the steel wire is washed with water to remove the lubricating powder, wherein the cooling water temperature of the die box is 30°C, the steel wire drawing specification is φ0.6 mm, and the total reduction of the steel wire drawing is controlled to be 89%.

[0030] S6: annealing, the stainless steel wire after the fine drawing in S5 is first passed through an electrolytic pickling tank (in the electrolytic pickling tank, the stainless steel wire serves as an anode, a lead plate serves as a cathode, and a dilute sulfuric acid solution serves as an electrolyte, the residual lubricating powder on the surface of the steel wire is removed through electrolytic pickling and water rinsing), then is passed through a tube type continuous annealing furnace for solid solution treatment, and then is cooled through a water cooling tank, wherein the solid solution treatment temperature is 1050°C, the protective gas is N2+H2, and the heat treatment production speed DV is controlled to be 20 (mm*m) / min.

[0031] S7: fine drawing, the stainless steel wire after the annealing in S6 is drawn through a water tank drawing machine, the total reduction is 93.75%, the lubricant is TF486, and the pass deformation is 14%.

[0032] S8: multiple tempering, the stainless steel wire after the fine drawing in S7 is reciprocating tempered through a tube furnace, the tempering times are 4, and the tempering temperature is 200°C. Example 2

[0033] S1: select φ5.5 mm solid solution pickling HRAP stainless steel wire rod, the chemical composition is: C: 0.035%, Si: 0.37%, Mn: 1.23%, P: 0.04%, S: 0.02%, Cr: 18.23%, Ni: 8.06%, N: 0.056%, and the balance is Fe.

[0034] S2: skin pass treatment, the selected φ5.5 mm stainless steel wire rod in S1 is immersed in a 80°C skin pass treatment liquid for 30 min, the skin pass treatment liquid is an aqueous solution of potassium sulfate and calcium sulfate, the concentration is 18 wt%, after soaking, it is taken out and dried in a warm air furnace, the drying temperature is 200°C, the drying time is 120 min, and the steel wire is used after the surface is dried.

[0035] S3: rough drawing, the φ5.5mm stainless steel wire rod after the skin treatment in S2 is drawn through a straight-in type drawing machine by a wire rack to obtain a semi-finished stainless steel wire through 6 passes, the first pass reduction is controlled at 30%, and then the reduction is decreased pass by pass, except that the sodium stearate lubricating powder NL305 (produced by Jiangyin Taifeng Chemical Technology Co., Ltd.) is used in the last pass, and the calcium stearate lubricating powder GB205 (produced by Jiangyin Taifeng Chemical Technology Co., Ltd.) is used in the other passes, and then the steel wire is washed with water to remove the lubricating powder, wherein the cooling water temperature of the die box is 30℃, the drawing steel wire specification is 2.55, and the total reduction of the wire rod drawing is 78.5%.

[0036] S4: annealing, the semi-finished stainless steel wire is first passed through an electrolytic pickling tank (the stainless steel wire is used as an anode, a lead plate is used as a cathode, and a dilute sulfuric acid solution is used as an electrolyte, the lubricating powder remaining on the surface of the steel wire is removed through electrolytic pickling and water rinsing), and then is subjected to solid solution treatment through a tubular continuous annealing furnace, and then is cooled through a water cooling tank, wherein the solid solution treatment temperature is 1100℃, the protective gas is N2+H2, and the heat treatment production speed DV is controlled at 22 (mmxm) / min.

[0037] S5: fine drawing, the steel wire after the annealing in S4 is sequentially passed through a skin tank, an oven and a straight-in type drawing machine through a wire rack to be drawn on line through 9 passes, the first pass reduction is controlled at 25%, and then the reduction is decreased pass by pass, the lubricating powder TF46 is used, and then the steel wire is washed with water to remove the lubricating powder, wherein the cooling water temperature of the die box is 30℃, the steel wire drawing specification is φ1.0mm, and the total reduction of the steel wire drawing is controlled at 84.6%.

[0038] S6: annealing, the fine-drawn stainless steel wire in S5 is first passed through an electrolytic pickling tank (the stainless steel wire is used as an anode, a lead plate is used as a cathode, and a dilute sulfuric acid solution is used as an electrolyte, the lubricating powder remaining on the surface of the steel wire is removed through electrolytic pickling and water rinsing), and then is subjected to solid solution treatment through a tubular continuous annealing furnace, and then is cooled through a water cooling tank, wherein the solid solution treatment temperature is 1100℃, the protective gas is N2+H2, and the heat treatment production speed DV is controlled at 22 (mmxm) / min.

[0039] S7: fine drawing, the stainless steel wire after the annealing in S6 is drawn through a water tank drawing machine, the total reduction is 91.59%, the lubricating agent is TF486, and the pass deformation is 15%.

[0040] S8: multiple tempering, the fine-drawn stainless steel wire in S7 is reciprocatingly tempered through a tubular furnace, the tempering times are 3, and the tempering temperature is 220℃.

[0041] Comparative Example 1

[0042] Compared with Example 1, the only difference is that φ5.5mm solid solution pickling HRA P stainless steel wire rod is selected in S1 step, and the chemical composition is: C: 0.035%, Si: 0.37%, Mn: 1.23%, P: 0.04%, S: 0.02%, Cr: 18.23%, Ni: 8.06%, N: 0.056%, and the balance is Fe.

[0043] Comparative Example 2

[0044] Compared with Example 1, the only difference is that φ5.5mm hot-rolled pickling HRP stainless steel wire rod is selected in S1 step, and the chemical composition is: C: 0.068%, Si: 0.37%, Mn: 1.23%, P: 0.04%, S: 0.02%, Cr: 18.23%, Ni: 8.06%, N: 0.056%, and the balance is Fe.

[0045] Comparative Example 3

[0046] Compared with Example 1, the only difference is that S8 multiple tempering step is not performed.

[0047] Comparative Example 4

[0048] Compared with Example 1, the only difference is that the wire drawing specification is φ0.45mm in S5 fine drawing step, and the total reduction of wire drawing is controlled at 93.75%; the total reduction of drawing is 89% in S7 fine drawing step.

[0049] Using the same test method, the tensile strength and knot tensile strength of Examples 1-2 and Comparative Examples 1-4 are tested, and the results are shown in the following table:

[0050]

[0051] In addition to the above examples, the present application also includes other embodiments, and any technical solutions formed by equivalent transformation or equivalent replacement shall fall within the protection scope of the claims of the present application.

Claims

1. A method for producing a stainless steel wire for a polytetrafluoroethylene hose reinforcement layer, characterized by: The method comprises the following steps: S1: selecting a solid solution pickling HRAP stainless steel wire rod, the chemical composition of which comprises: C: 0.06%-0.08%, Si≤1.00%, Mn≤2.00%, P≤0.045%, S≤0.03%, Ni: 8.0%-9.0%, Cr: 18.0%-19.0%, N<0.10%, and the balance being Fe; S2: film treatment, the stainless steel wire rod in the step S1 is immersed in a film treatment tank with a film treatment solution, and is taken out and dried after soaking; S3: rough drawing, the stainless steel wire rod after the film treatment in the step S2 is drawn through a straight-in type drawing machine by a wire rack to obtain a semi-finished stainless steel wire, and then the steel wire is washed, a lubricating powder is used in the drawing, and the cooling water temperature of a die box is 25-35℃; S4: annealing, the semi-finished stainless steel wire obtained in the step S3 is first acid washed through an electrolytic pickling tank, then is solid solution treated through a tubular continuous annealing furnace, and then is cooled through a water cooling tank by a passive wire feeding device; S5: fine drawing, the annealed steel wire in the step S4 is sequentially drawn through a film tank, an oven and a straight-in type drawing machine by a wire rack, and then the steel wire is washed, a lubricating powder is used in the drawing, and the cooling water temperature of a die box is 25-35℃; S6: annealing, the fine drawn stainless steel wire in the step S5 is first acid washed through an electrolytic pickling tank, then is solid solution treated through a tubular continuous annealing furnace, and then is cooled through a water cooling tank by a passive wire feeding device; S7: fine drawing, the annealed stainless steel wire in the step S6 is drawn through a water tank drawing machine; S8: multiple tempering, the fine drawn stainless steel wire in the step S7 is reciprocally tempered through a tubular furnace; The solid solution treatment temperature in the steps S4 and S6 is 1050-1120℃, the protective gas is N2+H2, and the heat treatment speed satisfies the formula: wire diameter D x heat treatment speed V = 20-25 (mm x m) / min, wherein the unit of the wire diameter is mm, and the unit of the heat treatment speed is m / min; The tempering times in the step S8 are 3-5, and the tempering temperature is 180-220℃.

2. The method of producing a stainless steel wire for a polytetrafluoroethylene hose reinforcement layer according to claim 1, characterized by: The film treatment solution in the step S2 is an aqueous solution of a mixture of potassium sulfate and sodium sulfate, the concentration of the film treatment solution is 15-21wt%, the temperature of the film treatment solution is 70-90℃, the soaking time is 20-30min, the drying temperature is 180-230℃, and the drying time is 100-150min.

3. The method of producing a stainless steel wire for a polytetrafluoroethylene hose reinforcement layer according to claim 1, characterized by: The total reduction in the step S3 is controlled to be 70-90%, and a sodium stearate lubricating powder is used in the last pass, and a calcium stearate lubricating powder is used in other passes.

4. The method of producing a stainless steel wire for a polytetrafluoroethylene hose reinforcement layer according to claim 1, characterized by: In the steps S4 and S6, the stainless steel wire is used as an anode, a lead plate is used as a cathode, and a dilute sulfuric acid solution is used as an electrolyte.

5. The method of producing a stainless steel wire for a polytetrafluoroethylene hose reinforcement layer according to claim 1, characterized by: In the step S5, the total reduction is controlled to be 70-90%, and a TF46 lubricating powder is used.

6. The method of producing a stainless steel wire for a polytetrafluoroethylene hose reinforcement layer according to claim 1, characterized by: In the step S7, the total reduction is 91-94%, a lubricating agent is TF486, and the pass deformation is 13%-15%.

7. A stainless steel wire for a polytetrafluoroethylene hose reinforcement layer, characterized by: The stainless steel wire for reinforcing layers of polytetrafluoroethylene hoses is prepared by the method in any one of claims 1-6.

Images