Alloy material for medium-high carbon rivet steel wire

Abstract

The application relates to the technical field of alloy materials for medium-high carbon rivets, and particularly discloses an alloy material for medium-high carbon rivet steel wires.The alloy material for medium-high carbon rivet steel wires is composed of the following components in percentage by weight: C 0.45-0.49 wt%; Si 0.14-0.37 wt%; Mn 0.72-0.784 wt%; P 0.0102-0.011 wt%; S 0.0102-0.011 wt%; Cr 0.0225-0.0245 wt%; Ni 0.1-0.3 wt%; Cu 0.1-0.25 wt%; trace elements 0-1 wt%; and the balance of Fe and inevitable impurities.The alloy material for medium-high carbon rivet steel wires can be used to prepare steel wires for medium-high carbon rivets, and has the advantages of 1 / 3 cold upsetting 100% non-cracking, good bar passing property, a difference between the initial and tail tensile strengths less than 5 MPa, good toughness and an elongation of more than 31%.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of alloy materials for medium-high carbon rivet, in particular to an alloy material for medium-high carbon rivet steel wire. BACKGROUND

[0002] The rivet steel wire is a base material for preparing a riveted part. In addition to the mechanical properties and the manufacturing quality, the uniformity of the wire bar performance is also required. The non-uniformity of the wire bar performance refers to the insufficient mechanical properties along the length direction, and the poor cold deformation capacity and the cracks in the steel wire during the drawing process.

[0003] With the improvement of the performance requirements of the riveted part, the performance requirements of the rivet steel wire are also improved. In order to prepare the rivet steel wire with good wire bar performance, the alloy as the raw material needs to have good plasticity or cold cracking resistance, so that the steel wire does not easily crack during the cold heading process of the riveted part (rivet) or during the cold forming.

[0004] Currently, several common alloy materials on the market, such as SWRCH10A, 10B21, ML08A1 and SWRCH22A, are subjected to 1 / 3 cold heading by using a cold heading testing machine. The lowest cold heading cracking rate is 0.9%, 0.8%, 1% and 1.2% in turn. The current alloy material has a high 1 / 3 cold heading cracking rate, and the cold forming is prone to cracking, which leads to a high defect rate or potential defect points in the riveted part that are not easy to be found. SUMMARY

[0005] In order to reduce the 1 / 3 cold heading cracking rate of the alloy material and improve the quality of the riveted part, the application provides an alloy material for medium-high carbon rivet steel wire.

[0006] In the first aspect, the application provides an alloy material for medium-high carbon rivet steel wire, which adopts the following technical scheme:

[0007] The alloy material for medium-high carbon rivet steel wire is composed of the following components by weight percentage: C 0.45-0.49wt%;

[0008] Si 0.14-0.37wt%;

[0009] Mn 0.72-0.784wt%;

[0010] P 0.0102-0.011wt%;

[0011] S 0.0102-0.011wt%;

[0012] Cr 0.0225-0.0245wt%;

[0013] Ni 0.1-0.3wt%;

[0014] Cu 0.1-0.25wt%;

[0015] trace elements 0-1wt%;

[0016] the balance being Fe, and inevitable impurities.

[0017] By adopting the technical scheme, the C element determines the strength, and the increase of the content of the C element increases the strength and hardness of the alloy material, but reduces the toughness and plasticity, in order to ensure that the material does not crack during cold deformation and has a certain strength, the content of C is controlled in the range of 0.45-0.49wt%, so as to obtain an alloy material with medium and high carbon content, and a rivet with excellent performance is prepared; the cooperation of Si, C, S and P improves the strength of the material, the content of Mn element is too high, which will cause grain coarsening and lead to the decrease of toughness, the existence of Cr element forms various carbides with C element, and the wear resistance of the material surface is improved.

[0018] The present application further studies, and finds that when the content of each element is in the above range, the 1 / 3 cold upsetting qualified rate of the prepared steel wire is 100%, the cold upsetting does not crack, the difference between the tensile strength of the head and tail of the steel wire is ≤5MPa, the bar straightness is good, the elongation is more than 31%, and the toughness is better. At this time, the alloy material has excellent plasticity or cold cracking resistance, and also has better toughness, bar straightness and other performances.

[0019] When the contents of C, Si, Mn, P, S and Cr are simultaneously reduced / increased, the performance of the steel wire is significantly reduced. When the contents of C, P and S are reduced, the 1 / 3 cold upsetting qualified rate of the steel wire is only 99.2%. When the content of C element is reduced and the contents of Mn, S and P elements are increased, the 1 / 3 cold upsetting qualified rate of the steel wire is only 98.7%. When there is no Ni and Cu, the 1 / 3 cold upsetting qualified rate of the steel wire is only 99.1%. When the content of C element is significantly increased, the 1 / 3 cold upsetting qualified rate of the steel wire is only 98.4%. It is shown that when the content of each element is out of the above range, the performance of the steel wire is significantly reduced.

[0020] Optionally, the alloy material is composed of the following components in weight percentage:

[0021] C 0.46-0.48wt%;

[0022] Si 0.22-0.32wt%;

[0023] Mn 0.74-0.77wt%;

[0024] P 0.0104-0.0108wt%;

[0025] S 0.0104-0.0108wt%;

[0026] Cr 0.023-0.024wt%;

[0027] Ni 0.15-0.25wt%;

[0028] Cu 0.15-0.2wt%;

[0029] trace elements 0wt%;

[0030] the balance being Fe and inevitable impurities.

[0031] By adopting the above technical scheme: when the weight percentage of each element is in the above range, the ratio of each element is more reasonable, the performance of the prepared alloy element is relatively stable, and the alloy element has excellent plasticity and cold cracking resistance, small tensile strength difference, and good wire rod passing property.

[0032] The performance of the prepared steel wire is detected, the 1 / 3 cold upsetting qualified rate is kept at 100%, the 1 / 3 cold upsetting does not crack, the tensile strength difference of the steel wire head and tail is ≤4.64%, the wire rod passing property is better, the elongation is more than 31.5%, and the toughness is better.

[0033] Optionally, the alloy material is composed of components with the following weight percentages:

[0034] C 0.47wt%;

[0035] Si 0.27wt%;

[0036] Mn 0.76wt%;

[0037] P 0.106wt%;

[0038] S 0.106wt%;

[0039] Cr 0.0235wt%;

[0040] Ni 0.2wt%;

[0041] Cu 0.15wt%;

[0042] trace elements 0wt%;

[0043] the balance being Fe and inevitable impurities.

[0044] By adopting the above technical scheme: when the content of each element in the alloy is as above, the content of each element is optimally matched. The performance of the prepared steel wire is detected, the 1 / 3 cold upsetting qualified rate is kept at 100%, the 1 / 3 cold upsetting does not crack, the tensile strength difference of the steel wire head and tail is further reduced to 4.59%, the wire rod passing property is better, the elongation is more than 32.7%, and the toughness is better.

[0045] Optionally, the microelement is one or more of Al, Ce, and Y.

[0046] By using the above technical solution: when Al, Ce, or Y is used alone, each has a certain effect of improving the toughness of the alloy material, but the improvement capacity is different,

[0047] When no microelement is used, the elongation of the steel wire is 31.1%.

[0048] When Al is used alone, the elongation of the steel wire is 32.9%; when Ce is used alone, the elongation of the steel wire is 32.0%; and when Y is used alone, the elongation of the steel wire is 31.8%, indicating that Al has the best effect of improving toughness among the three.

[0049] Optionally, the microelement is composed of Al, Ce, and Y.

[0050] By using the above technical solution: Al, as a strong deoxidizer, can generate highly fine and ultra-fine oxides and disperse in the alloy material to hinder the growth of crystal grains; the presence of Ce also has a good refining modification effect, but when the content of Ce is low, it cannot achieve a good effect of refining grains, and when the content of Ce is high, it reacts with Al and Si to generate AlSiCe intermetallic compounds and penetrates at the grain boundaries to reduce the modification effect, so the effect of Ce in refining grains is limited, and therefore Y element is added, because the ionic radius of Y is 0.09 nm, which is larger than the ionic radius of Ce 3+ , so that atomic clusters are formed on the surface of Ce crystals, covering the surface of Ce crystals and hindering the formation of intermetallic compounds of Ce and Al and Si, thereby improving the modification effect and refining the grains, increasing the occlusion opportunity between the grains, and being not conducive to the transmission of cracks, and further improving the flexibility of the alloy material, the steel wire does not crack during cold heading, and the wire rod has good properties.

[0051] When no Al, Ce, and Y are used, the elongation of the steel wire is 31.1%, when one or two of Al, Ce, and Y are used as microelements, the elongation of the steel wire is only 33.4% at most, and when the microelement is a composite of Al, Ce, and Y, the elongation of the steel wire is significantly improved to more than 35.8%, the toughness of the steel wire is significantly improved, and there is an obvious synergistic effect among the three.

[0052] Optionally, in the alloy material, the weight percentage of the microelement is 0.6-0.8wt%.

[0053] By adopting the technical scheme, when the content of the microelement is increased within a certain range, the toughness of the alloy material can be improved, and when the content is increased within the range, the elongation of the steel wire is increased to 36.7-37.6%, the toughness of the steel wire is better, and the performance of the riveting piece is better.

[0054] Optionally, in the alloy material, the weight percentage of Ce is 0.1-0.15wt%.

[0055] By adopting the technical scheme, the performance of the steel wire is detected, when the content of Ce is outside the range, the elongation of the steel wire is 37.6%, and when the content of Ce is within the range, the compounding effect of Ce, Al and Y is better, the synergistic effect of the three elements on the toughness of the alloy material is best, the toughness of the steel wire is improved, and the elongation of the steel wire is 37.9-38.3%.

[0056] Optionally, in the alloy material, the weight percentage of Y is 0.25-0.3wt%.

[0057] By adopting the technical scheme, when the content of Y is outside the range, the elongation of the steel wire is 38.3%, and when the content of Y is within the range, the compounding effect of Y, Al and Ce is better, the synergistic effect of the three elements on the toughness of the alloy material is best, the toughness of the steel wire is improved, and the elongation of the steel wire is 38.7-39.0%.

[0058] In summary, the present application has the following advantages:

[0059] 1. The content of C, Si, Mn, P, S, Cr, Ni, Cu, Fe elements is controlled, so that the steel wire has excellent toughness and cold cracking resistance, no cracking phenomenon after 1 / 3 cold upsetting, and the steel wire has good bar quality, which ensures the product performance of the riveting piece; 2. In the present application, trace elements Al, Ce and Y are added at the same time, the presence of Y hinders the combination of Al and Ce, so that the two elements fully play the effect of refining grains, and the compounding of the three elements further improves the toughness of the alloy material. DETAILED DESCRIPTION

[0060] The present application will be further described in detail below in combination with examples.

[0061] Examples 1-5

[0062] An alloy material for a medium-high carbon rivet steel wire, the components and their corresponding weight percentages are as shown in Table 1, and is prepared by the following steps:

[0063] S1, using raw material iron ore;

[0064] S2, adding raw materials into an electric arc furnace for heating and melting to extract molten steel;

[0065] S3, after the initial smelting furnace molten steel into the furnace, by blowing Ar and O2 mixed gas into the furnace, and detect the content of each element, blowing process is divided into oxidation, reduction, refining period;

[0066] S4, continuous casting: the molten steel into the continuous casting machine, control the casting temperature is 1570℃, and electromagnetic stirring, continuous casting billet dynamic reduction of 0.5%, continuous casting billet superheat is 15℃, continuous casting billet pull speed is 1.0m / s;

[0067] S5, rolling: the opening temperature control is 900℃, control each pass reduction rate in 20%, rough rolling cumulative reduction rate is 80%, medium rolling cumulative reduction rate is 80%, finishing rolling cumulative reduction rate is 45%, into the finishing mill temperature is 860℃, wire temperature is 850℃, according to the speed of 0.5℃ / s cooling to get wire;

[0068] S6, the wire prepared by the step S5, the steps are heat treatment, pickling, phosphating, borax treatment and drawing treatment;

[0069] 1) heat treatment: the borax treated steel is added to a tubular continuous annealing furnace, and is kept at 790℃ for 5h at a speed of 25℃ / min, then is cooled to 650℃ at a speed of 25℃ / h, and is removed from the furnace for cooling, and the protective gas is ammonia decomposition gas;

[0070] 2) pickling, phosphating: the heat treated steel is added to a pickling solution, is pickled at a temperature of 60℃ for 3min, is washed with water, then is immersed in a phosphating solution at 75℃ for 3min, is washed with water, is immersed in a saponification treatment solution at 50℃ for 2min, and is dried at 50℃ for 20min;

[0071] The pickling solution is obtained by uniformly mixing 100kg of 25wt% hydrochloric acid and 3kg of hydrochloric acid corrosion inhibitor; the phosphating solution is obtained by uniformly mixing 100kg of water and 13kg of phosphating agent (phosphating agent WX-F3102); and the saponification treatment solution is obtained by uniformly mixing 100kg of water, 15kg of saponifying agent (JF-L61), and 1.5kg of saponifying oil (DRK-3010) under conventional stirring.

[0072] The hydrochloric acid corrosion inhibitor is obtained from Langfang Xingrui Chemical Building Material Co., Ltd.

[0073] 3) borax treatment: after the temperature is raised to 85℃ of the surface of the steel, the borax solution is spin-coated under the conditions of a rotation speed of 4000rpm / 30s and a drop amount of 80μl, and is dried at 130℃ for 12min;

[0074] Borax solution: 25 kg of 10 water borax, 0.75 kg of trisodium phosphate was dissolved in 100 kg of water.

[0075] 4) Drawing treatment: the steel material after pickling and phosphating was put into a straight drawing machine, and the circulating water temperature was controlled at 30°C during drawing;

[0076] 5) Steps 1) -4) were repeated once each time, wherein in the first step 4), the deformation amount of the first pass was 30%, the deformation amount of the intermediate pass was 20%, and the deformation amount of the last pass was 15%; in the second step 3), the deformation amount of the first pass was 10%, the deformation amount of the intermediate pass was 20%, and the deformation amount of the last pass was 15%, thereby obtaining the medium-high carbon rivet steel wire.

[0077] Table 1: Components and their weight percentages (wt%) in Examples 1-5

[0078]

[0079]

[0080] Comparative Examples 1-6

[0081] An alloy material, which is different from Example 1, in that the components and their corresponding weight percentages are as shown in Table 2.

[0082] Table 2: Components and their weight percentages (wt%) in Comparative Examples 1-6

[0083]

[0084] Examples 6-19

[0085] An alloy material for medium-high carbon rivet steel wire, which is different from Example 1, in that the components and their corresponding weight percentages are as shown in Tables 3-1 and 3-2.

[0086] Table 3-1: Components and their weight percentages (wt%) in Examples 1, 6-13

[0087]

[0088]

[0089] Table 3-2: Components and their weight percentages (wt%) in Examples 14-19

[0090]

[0091] Performance test

[0092] The steel wires (diameter 2.55 mm) prepared from the alloy materials in the examples and comparative examples according to their preparation processes were subjected to the following performance tests, and the test results are recorded in Table 4.

[0093] Test method

[0094] 1. 1 / 3 cold upsetting pass rate: in actual production, the steel wires prepared were subjected to 1 / 3 cold upsetting using a cold upsetting tester, the number of cracked steel wires A1 was observed and recorded, the sample capacity was 1000, and the 1 / 3 cold upsetting pass rate was calculated;

[0095] 1 / 3 cold upsetting pass rate A = 1 - A1 / 1000*100%, the larger the pass rate, the better the cold upsetting performance of the steel wire.

[0096] 2. Straightness: 20 cm of the head end and tail end of the steel wire were taken as samples, the tensile strength of the samples was tested according to the method in GB / T 228.1-2010 using a tensile testing machine, the difference in tensile strength of the head and tail samples of each steel wire was recorded, the smaller the difference, the more uniform the mechanical distribution in the length direction of the steel wire, and the better the straightness.

[0097] 3. Elongation: one end of the steel wire was fixed on a wire elongation tester HE-XC-250, the other end was connected to the tension sensor on the tester, the tension was increased at a constant speed to gradually stretch the steel wire until it was broken, and the elongation of the steel wire at this time was recorded, the larger the breaking elongation, the better the toughness of the steel wire.

[0098] Table 4 Performance test results

[0099]

[0100]

[0101] Referring to Table 4, the alloy materials in Examples 1-5 were used in the amount range of the element ratio, the 1 / 3 cold upsetting pass rate of the steel wires prepared therefrom was 100%, the cold upsetting did not crack, the difference in tensile strength of the head and tail samples was less than 5 MPa, the straightness was good, the elongation was as high as 31.0-32.7%, and the toughness was relatively good. Among them, Examples 2-4 were preferred examples, and Example 3 had the best performance.

[0102] However, the 1 / 3 cold upsetting pass rate of the steel wires prepared from the alloy materials in Comparative Examples 1-6 was less than 99.2% at most, the difference in tensile strength was more than 6 MPa, and the elongation was only 22.4-24.3%, indicating that when the content of each element is outside the range of Examples 1-5 or other alloy elements are used, the performance of the prepared steel wire decreases.

[0103] The difference between Examples 6-19 and Example 1 is that the alloy material contains trace elements, and the trace elements are one or more of Al, Ce and Y.

[0104] As can be seen from the combination of Embodiment 1, Embodiments 6-8 and Table 4, when Al, Ce and Y are added alone, the toughness of the alloy material can be appropriately improved, and the toughness of the alloy material is optimal when Al is added, but the effect of Ce and Y on the toughness of the material is not great due to the small amount used.

[0105] As can be seen from the combination of Embodiment 6, Embodiment 9 and Table 4, when both Al and Ce are used in Embodiment 9, the elongation of the alloy material is increased from 32.9% when Al is used alone to 33.4%, the toughness of the alloy material is improved, but the improvement is not great, and there is still room for improvement.

[0106] As can be seen from the combination of Embodiment 9, Embodiments 10-13 and Table 4, since Al, Ce and Y are used in Embodiments 10-13, the elongation is further increased to 35.8-37.6%, and the toughness of the alloy material is significantly improved. The reason is that in Embodiment 9, more Ce is added to improve the toughening effect of Ce on the alloy material, and Ce reacts with Al and Si to form AlSiCe intermetallic compounds, which penetrate at the grain boundaries to reduce the modification effect, so the effect of Ce on grain refinement is limited. In Embodiments 10-13, Y element is further added to form atomic clusters on the surface of Ce crystals, which cover the surface of Ce crystals and hinder the formation of intermetallic compounds between Ce and Al and Si, thereby improving the modification effect and refining the grains, increasing the chance of engagement between the grains, which is not conducive to the propagation of cracks, and further improving the toughness of the alloy material. It can be known that the toughness of the alloy material is better when the amount of the trace element added in the alloy material is 0.6-0.8wt%.

[0107] As can be seen from the combination of Embodiment 12, Embodiments 14-16 and Table 4, when the weight percentage of Ce in the alloy material is 0.1-0.15wt%, the toughness of the alloy material is better.

[0108] As can be seen from the combination of Embodiment 15, Embodiments 17-19 and Table 4, when the weight percentage of Y in the alloy material is 0.25-0.3wt%, the toughness of the alloy material is better.

[0109] The specific embodiments are merely an explanation of the present application, and are not a limitation of the present application. Those skilled in the art can make modifications to the embodiments without creative contribution after reading the present specification, and the modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. Medium and high carbon rivet steel wire, characterized in that, The wire is made of alloy material and is obtained through heat treatment, pickling, phosphating, borax treatment and drawing. The heat treatment involves adding the steel into a tubular continuous annealing furnace; the drawing process involves using cooling circulating water at a temperature of 30°C during wire drawing. The alloy material used in this steel wire is composed of the following components by weight percentage: C 0.45-0.49wt%; Si 0.14-0.37wt%; Mn 0.72-0.784wt%; P 0.0102-0.011wt%; S 0.0102-0.011wt%; Cr 0.0225-0.0245wt%; Ni 0.1-0.3wt%; Cu 0.1-0.25wt%; trace elements 0-1wt%; the balance being Fe and unavoidable impurities.

2. The medium-high carbon rivet wire according to claim 1, characterized in that: The alloy material is composed of the following components by weight percentage: C 0.46-0.48wt%; Si 0.22-0.32wt%; Mn 0.74-0.77wt%; P 0.0104-0.0108wt%; S 0.0104-0.0108wt%; Cr 0.023-0.024wt%; Ni 0.15-0.25wt%; Cu 0.15-0.2wt%; Trace elements 0 wt% The balance is Fe and unavoidable impurities.

3. The medium-high carbon rivet wire according to claim 2, characterized in that: The alloy material is composed of the following components by weight percentage: C 0.47wt%; Si 0.27wt%; Mn 0.76wt%; P 0.106wt%; S 0.106wt%; Cr 0.0235wt%; Ni 0.2wt%; Cu 0.15wt%; Trace elements 0 wt% The balance is Fe and unavoidable impurities.

4. The medium-high carbon rivet wire according to claim 1, characterized in that: The trace element is one or more of Al, Ce, and Y.

5. The medium-high carbon rivet wire according to claim 4, characterized in that: The trace elements consist of Al, Ce, and Y.

6. The medium-high carbon rivet wire according to claim 4, characterized in that: In the alloy material, the weight percentage of the trace elements is 0.6-0.8 wt%.

7. The medium-high carbon rivet wire according to claim 5, characterized in that: In the alloy material, the weight percentage of Ce is 0.1-0.15 wt%.

8. The medium-high carbon rivet wire according to claim 5, characterized in that: In the alloy material, the weight percentage of Y is 0.25-0.3 wt%.

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