CN115637310A - Process improvement method for improving quality of axle steel product - Google Patents
Process improvement method for improving quality of axle steel product Download PDFInfo
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- CN115637310A CN115637310A CN202211398150.3A CN202211398150A CN115637310A CN 115637310 A CN115637310 A CN 115637310A CN 202211398150 A CN202211398150 A CN 202211398150A CN 115637310 A CN115637310 A CN 115637310A
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Abstract
The invention relates to the field of metallurgy, and discloses a process improvement method for improving quality of an axle steel product, which is characterized by comprising the following steps of controlling the content of Al in molten steel after refining: 0.02-0.035%; adding about 120kg of ferrotitanium after refining the white slag to ensure that the finished product [ Ti ] is controlled as follows: 0.020-0.025%; reducing the cooling intensity in the crystallizer in the continuous casting process; and the stirring intensity of the solidification tail end electromagnetic stirring is improved at the tail end electromagnetic stirring position. The improved process method for improving the quality of the axle steel product can better ensure the grain size quality and the flaw detection quality of the LZ50 axle blank.
Description
Technical Field
The invention relates to the field of metallurgy, in particular to a process improvement method for improving the quality of an axle steel product.
Background
The axle steel is a steel material applied to railway locomotives and vehicle axles, and is a professional steel used for manufacturing railway locomotives and vehicle axles. The axle is a key part for bearing the mass of the locomotive and the vehicle, and bears a plurality of complex stresses such as rotating bending, impact and the like in operation, and fatigue crack is a main failure mode of the axle. Thus, axle steels are required to have sufficient strength and toughness, and to be very severe in respect of various metallurgical defects that may be sources of axle cracks.
With the acceleration loading of railway vehicles and the increase of railway export vehicles, higher requirements are put on the product quality of LZ50 axle blanks. The grain size of the LZ50 axle blank is improved from the grain size of more than or equal to 5 grade to more than or equal to 6 grade in a primary normalizing state, no mixed crystal is required, and the flaw detection quality of the LZ50 axle blank is required to reach SEP 1921D/D grade ultrasonic inspection standard.
The grain sizes of different batches of materials produced by the existing metallurgy process are different, the fluctuation range is between 5 grades and 7 grades, namely, the grain size of the LZ50 axle blank in a one-time normalizing state can be more than or equal to 5 grades, but the grain sizes of all batches of materials can not be more than or equal to 6 grades. In addition, the LZ50 axle blank often suffers from the problem of spot segregation, which causes the LZ50 axle blank to be defective in the ultrasonic flaw detection.
Therefore, how to ensure that the produced LZ50 axle blank can better meet the requirements of grain size quality and flaw detection quality from the aspect of metallurgical technology becomes a subject which needs to be solved urgently in the metallurgical industry.
Disclosure of Invention
In order to solve the problems of low grain size grade and low flaw detection quality qualification rate of the LZ50 axle blank in the prior art, the invention provides a process improvement method for improving the quality of an axle steel product, and the process improvement method for improving the quality of the axle steel product can better ensure the grain size quality and the flaw detection quality of the LZ50 axle blank.
The invention provides a process improvement method for improving the quality of an axle steel product, which comprises the following steps:
controlling the content of [ Al ] in the molten steel after refining as follows: 0.02-0.035%;
adding about 120kg of ferrotitanium after refining the white slag to ensure that the content of finished product [ Ti ] is controlled as follows: 0.020-0.025%;
reducing the cooling intensity in the crystallizer in the continuous casting process;
and the stirring intensity of the solidification tail end electromagnetic stirring is improved at the tail end electromagnetic stirring position.
Preferably, the method for controlling the content of [ Al ] is to sample the molten steel and add an aluminum wire to the molten steel according to the sampling result.
Preferably, the method for adding [ Ti ] into the molten steel comprises the following steps: and adding titanium alloy into molten steel after refining the white slag.
Preferably, the reduction of the cooling strength in the continuous casting process is: and reducing the flow of the cooling water of the first cooling from 4000L/min to 3550L/min-3650L/min.
Preferably, the stirring intensity of the electromagnetic stirring at the solidification end is increased by: the operation period of electromagnetic stirring at the solidification tail end is changed from 8 seconds of forward rotation, 2 seconds of stop and 8 seconds of reverse rotation to 12 seconds of forward rotation, 2 seconds of stop and 12 seconds of reverse rotation, namely the stirring time in the operation period of electromagnetic stirring at the solidification tail end is prolonged.
According to the technical scheme, a proper amount of Al and Ti is added into the molten steel, so that the molten steel solution after refining contains fully dispersed AlN and TiN, the AlN and TiN can be distributed at all positions of the molten steel, austenite grains are effectively prevented from growing, the grain size grade of the LZ50 axle blank is controlled to meet the quality requirement of grain size, and mixed crystals can be effectively avoided. The cooling intensity in the continuous casting process is reduced, so that the continuous casting molten steel can be mixed more sufficiently, the stirring intensity of electromagnetic stirring at the solidification end is improved in a matching manner, the aim of uniformly mixing the temperature and the components of the molten steel in the continuous casting stage is fulfilled, the problem of point-shaped segregation in the LZ50 axle blank is effectively avoided, and the flaw detection qualification rate of the LZ50 axle blank ultrasonic wave is improved.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:
FIG. 1 is a schematic diagram of sampling points for a phi 600 casting surface point segregation;
FIG. 2 is a graph showing a comparison of carbon content before and after the practice of a process improvement method for improving the quality of an axle steel product;
FIG. 3 is a comparison curve of carbon segregation indexes before and after the practice of a process improvement method for improving the quality of axle steel products.
Description of the reference numerals
11 sampling lines for 1 phi 600 castings
12 sampling point 13 casting center
Detailed Description
The following describes in detail embodiments of the present invention with reference to the drawings. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.
In the present invention, unless otherwise specified, the directional words included in the terms "front, rear" and the like merely represent the directions of the terms in a conventional use state or are colloquially known by those skilled in the art, and should not be construed as limiting the terms.
A process improvement method for improving the quality of axle steel products comprises
Controlling the content of [ Al ] in the molten steel after refining as follows: 0.02 to 0.035 percent;
adding about 120kg of ferrotitanium after refining the white slag to ensure that the content of finished product [ Ti ] is controlled as follows: 0.020-0.025%;
reducing the cooling intensity in the crystallizer in the continuous casting process;
and the stirring intensity of the solidification tail end electromagnetic stirring is improved at the tail end electromagnetic stirring position.
Through the implementation of the technical scheme, the content of residual [ Al ] in the molten steel is controlled as follows: 0.02-0.035%, the residual Al in the molten steel can be combined with the N in the molten steel to form AlN, and the AlN can prevent the austenite grains from growing. If the content of Al is lower than 0.020%, the content of a fine and dispersedly distributed refractory compound AlN in steel is insufficient, austenite grains cannot be effectively prevented from growing in the whole section range of the LZ50 axle blank, so that the normalizing heating crystal of the LZ50 axle blank is extremely easy to coarsen, and experience shows that when the content of AlN in molten steel is insufficient, coarse grains appear when the normalizing heating temperature of the LZ50 axle blank reaches 800 ℃, coarse grain tissues appear in the LZ50 axle blank at the normalizing temperature of 860 ℃, and the coarse grain tissues can seriously influence the grain size quality rating of the LZ50 axle blank. However, the content of the Al is not too high, and if the content of the Al is higher than 0.035%, impurities such as aluminum oxide and the like are increased along with the increase of the content of the Al, and excessive similar impurities are mixed in the steel, and the impurities are harmful to the flaw detection quality when being densely and stacked or distributed in a chain shape, so that the qualified rate of the ultrasonic inspection of the steel billet is correspondingly reduced.
In addition, since impurities such as alumina are different from the metal matrix in deformability, when the steel material is plastically deformed by an external force, a local stress peak may be generated on a bonding surface between the impurities and the metal, and if the stress is not relaxed in time, the local stress peak may exceed a bonding force between the impurities and the metal matrix as the metal continues to flow, thereby causing separation of the impurities from the metal matrix and further forming the voids.
According to the control that the content of finished product [ Ti ] is 0.020-0.025 percent, the [ Ti ] can be combined with [ N ] in molten steel to form TiN, the TiN can prevent austenite grains from growing together with AlN, and the coarsening temperature of the austenite grains is increased to be above 920 ℃, so that the sensitivity of the LZ50 axle blank to a heat treatment process is reduced, the problem of low grain size grade qualification rate after the normalizing heat treatment of the LZ50 axle blank is solved, and the problem of crystal mixing can be obviously avoided.
The cooling strength is reduced during molten steel casting, so that the cooling speed of the molten steel is prevented from being slowed, the molten steel is not easy to crystallize out columnar crystals or dendritic crystals, and the overall fluidity of the molten steel is improved; under the condition that the fluidity of the molten steel is ensured, the electromagnetic stirring action area at the solidification tail end is obviously increased; under the condition, the molten steel can be stirred more fully by improving the stirring strength of electromagnetic stirring at the solidification tail end, so that the internal temperature and components of the molten steel can be uniformly mixed to the maximum extent, the point segregation of a casting blank is avoided, and the qualification rate of the LZ50 axle blank ultrasonic flaw detection is improved.
In this embodiment, it is preferable that the [ Al ] content is controlled by sampling the molten steel and adding an aluminum wire to the molten steel according to the sampling result.
The deoxidation capability of various elements is in the order of strong to weak: al, ti, B, si, C, V, cr and Mn. Al is one of the most commonly used deoxidizing agents in the steel production process, and Al is an extremely strong deoxidizing element, so that Al can be added into molten steel in many links in the steel making process.
And adding an aluminum block as a deoxidizer to deoxidize the molten steel in the process of tapping from the converter to the ladle. About 1/3 of the tapping time of the converter, adding aluminum blocks according to the standard of 0.8-1.5kg/t, melting the aluminum blocks in a ladle and fully mixing the aluminum blocks with molten steel to form alumina steel slag, and fully floating the aluminum steel slag in the following process.
The molten steel components in the converter are detected during converter tapping, and the length of an aluminum wire required to be injected into a steel ladle is calculated according to the detection result. Generally, it is necessary to inject 200 to 300m of aluminum wire (Al wire weighs 0.35 kg/m) into the molten steel, and therefore, about 70 to 105kg of aluminum is added to the molten steel after tapping of the converter is completed. The aluminum is burnt and consumed in the steel ladle, so the actually injected aluminum wire is usually more than the required addition amount of Al, the content of the [ Al ] in the molten steel after the converter is controlled to be 0.040-0.060%, the content is slightly higher than the content of the refined [ Al ] of 0.02-0.035%, and the higher [ Al ] content is used for deoxidation and consumption in the subsequent process.
The adding amount of the aluminum is determined according to the end point carbon content of the converter, and the end point carbon content of the converter is targeted as follows: 0.09% -0.13%. Wherein, the higher the end point carbon content is, the lower the oxidability of the molten steel is, and less deoxidizers can be added; the lower the end point carbon content is, the stronger the oxidability of molten steel is, and more deoxidizing agent needs to be added correspondingly. Specifically, when the end point carbon content is less than 0.10%, adding 1.5kg/t of aluminum block and 300m of aluminum wire; when the end point carbon content is between 0.10% and 0.15%, and comprises 0.10% and 0.15%, adding 1.0kg/t of aluminum block and 250m of aluminum wire; when the end point carbon content is more than 0.15%, 0.8kg/t of aluminum block is added, and 200m of aluminum wire is added.
In the diffusion deoxidation stage, feO exists in the molten slag and the molten steel at the same time, and the FeO in the molten slag and the FeO in the molten steel can be mutually transferred and tend to be balanced. This situation follows the distribution law of heterogeneous equilibrium in physicochemical. In the diffusion deoxidation stage, aluminium particles are added into the molten slag to react with FeO, the generated solid slag alumina is remained in the molten slag, the reduced iron is returned to the molten steel, and the FeO in the molten slag is consumed, so that the FeO content in the molten steel is reduced, the concentration balance of FeO in the molten slag and the molten steel is broken, the FeO in the molten steel is diffused into the molten slag, and the purpose of deoxidation is achieved.
Carbon powder and silicon carbide are added into the molten steel together with the aluminum particles in the diffusion deoxidation stage, the total amount of the added carbon powder and silicon carbide is about 0.8-1.6kg/t, but the aluminum particles added in the diffusion deoxidation stage are all used for slagging, and part of aluminum after the converter is added is used for deoxidation consumption in the refining stage, and the final residual [ Al ] content in the molten steel is as follows: 0.02-0.035%.
In this embodiment, preferably, the method of adding [ Ti ] to the molten steel is specifically: after refining the white slag, adding ferrotitanium into the molten steel.
After white slag is generated, adding ferrotitanium alloy into molten steel according to the standard of controlling the content of [ Ti ] to be 0.020-0.025%, and taking a molten steel sample for component detection after the alloy is melted, so as to ensure that the content of [ Ti ] in the molten steel meets the requirement.
In this embodiment, preferably, the reducing the cooling intensity in the continuous casting process includes reducing the flow rate of the cooling water of the first cooling from 4000L/min to 3550L/min-3650L/min.
The first cooling is carried out in the crystallizer, a layer of blank shell is formed on the outer side of the molten steel under the action of the cooling water of the first cooling, after the flow rate of the cooling water is reduced, the amount of the cooling water passing through the crystallizer in unit time is reduced, the heat taken away by the cooling water is correspondingly reduced, the thickness of the blank shell on the outer side of the molten steel is reduced, namely the volume proportion of the molten steel in the blank shell is increased, namely the fluidity of the molten steel is enhanced, and the uniform mixing of the molten steel in the crystallizer is facilitated, so that the occurrence of point segregation is avoided.
Preferably, after the flow rate of cooling water for the first cooling is reduced from 4000L/min to 3550L/min to 3650L/min, the thickness of a blank shell in the crystallizer is only about 1-2mm, and the blank shell with the thickness can meet the production requirement of the process stage, and a liquid core positioned in the blank shell still has good fluidity, so that a good environment is provided for electromagnetic stirring at the solidification tail end.
And after the strong cooling at the first cooling position is changed into the weak cooling, the situation that the center of the molten steel is heated outwards due to large temperature difference between the inside and the outside of the molten steel can be avoided, and the quality of a casting blank is favorably controlled.
In this embodiment, it is preferable that the stirring intensity of the solidification end electromagnetic stirring is increased by: the operation period of electromagnetic stirring at the solidification tail end is changed from 8 seconds of forward rotation, 2 seconds of stop and 8 seconds of reverse rotation to 12 seconds of forward rotation, 2 seconds of stop and 12 seconds of reverse rotation, namely the stirring time in the operation period of electromagnetic stirring at the solidification tail end is prolonged.
In order to obtain better stirring effect, the effective stirring time in the operation period of the solidification end electromagnetic stirring can be prolonged, the original period is improved to 26 seconds from 18 seconds, the stop time in the period is unchanged, and the effective stirring time is improved to 24 seconds from 16 seconds. The temperature of the molten steel after the electromagnetic stirring at the solidification tail end tends to be consistent more easily, and the material in the molten steel tends to be even more easily, so that the generation of point segregation is favorably inhibited.
Through the implementation of the technical scheme, a casting of phi 600 is selected, the surface material of the casting is sampled, carbon segregation data is analyzed, and the obtained carbon component, namely the carbon segregation index is shown in a table 1:
TABLE 1
In the sampling process, firstly, two mutually perpendicular diameters need to be taken as two sampling lines 11 on the cross section of the phi 600 casting, the two sampling lines 11 are divided into 4 radiuses by the center of the casting circle, on each radius, a sampling point 12 is set at intervals of 30mm by taking the center of the casting circle 13 as a starting point, 10 sampling points 12 are totally set on each radius, the center of the casting circle 13 is set as a sampling point 0, and 41 sampling points 12 are set on the surface of the whole phi 600 casting.
After the 41 sampling points 12 are determined, each sampling point 12 is marked with a serial number, and a 30 g sample is drilled at the position of each sampling point 12 by using a drilling machine and stored corresponding to the serial number of the sampling point 12. Finally, the carbon-sulfur analyzer is used for carrying out carbon-sulfur analysis on all the samples to obtain the carbon component of the sampling point 12, and the carbon component of the sampling point is recorded corresponding to the serial number of the sampling point.
And dividing the obtained carbon component value by the carbon component value in the smelting process to obtain the carbon segregation index of the sampling point.
The data of the carbon component in Table 1 were evaluated as a range, and the range was 0.059%.
By adopting the same sampling method, 41 points of castings with phi of 600 are sampled before the process is improved, and the obtained carbon components, namely the carbon segregation indexes are shown in a table 2:
TABLE 2
The range of the carbon component data in table 2 is calculated, the range is 0.13%, and compared with the range of the carbon component after the process improvement, the range is 0.059%, so that the condition of carbon segregation on the cross section of the casting is effectively controlled after the process improvement.
With reference to the attached drawings 2-3, it can be obviously found that after the process improvement of the invention, the oscillation amplitude of the carbon component curve is reduced, that is, the carbon component difference at different positions on the cross section of the casting is reduced; the difference in the carbon segregation indexes becomes smaller.
The preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications can be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.
It should be noted that, in the above embodiments, the various features described in the above embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, the present invention does not separately describe various possible combinations.
In addition, any combination of the various embodiments of the present invention can be made, and the same should be considered as the disclosure of the present invention as long as the idea of the present invention is not violated.
Claims (5)
1. A process improvement method for improving the quality of an axle steel product is characterized by comprising the following steps:
controlling the content of [ Al ] in the molten steel after refining as follows: 0.02-0.035%;
adding about 120kg of ferrotitanium after refining the white slag to ensure that the content of finished product [ Ti ] is controlled as follows: 0.020-0.025%;
reducing the cooling intensity in the crystallizer in the continuous casting process;
and the stirring intensity of the solidification tail end electromagnetic stirring is improved at the tail end electromagnetic stirring position.
2. The improved process for improving the quality of axle steel products according to claim 1, wherein said control of [ Al ] content is performed by sampling the molten steel and adding aluminum wire to the molten steel according to the sampling result.
3. The improved process for improving the quality of an axle steel product according to claim 1, wherein the method for adding [ Ti ] to the molten steel comprises: after refining the white slag, adding ferrotitanium into the molten steel.
4. The improved process for improving the quality of axle shaft steel products according to claim 1, wherein the step of reducing the cooling intensity in the continuous casting process is as follows: and reducing the flow of the cooling water of the first cooling from 4000L/min to 3550L/min-3650L/min.
5. The improved process for improving the quality of axle steel products as claimed in claim 1, wherein the stirring intensity of the electromagnetic stirring at the solidification end is: the operation period of electromagnetic stirring at the solidification tail end is changed from 8 seconds of forward rotation, 2 seconds of stop and 8 seconds of reverse rotation to 12 seconds of forward rotation, 2 seconds of stop and 12 seconds of reverse rotation, namely the stirring time in the operation period of electromagnetic stirring at the solidification tail end is prolonged.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101497968A (en) * | 2009-03-16 | 2009-08-05 | 江苏沙钢集团淮钢特钢有限公司 | Steel for microalloying lorry axle and technique for producing the same |
| WO2022078018A1 (en) * | 2020-10-15 | 2022-04-21 | 中天钢铁集团有限公司 | Control method for segregation and net carbide of 86-grade high-strength cord steel wire rod |
| CN115026251A (en) * | 2022-06-28 | 2022-09-09 | 芜湖新兴铸管有限责任公司 | Process improvement method for improving flaw detection qualification rate of high-aluminum steel |
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2022
- 2022-11-09 CN CN202211398150.3A patent/CN115637310A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101497968A (en) * | 2009-03-16 | 2009-08-05 | 江苏沙钢集团淮钢特钢有限公司 | Steel for microalloying lorry axle and technique for producing the same |
| WO2022078018A1 (en) * | 2020-10-15 | 2022-04-21 | 中天钢铁集团有限公司 | Control method for segregation and net carbide of 86-grade high-strength cord steel wire rod |
| CN115026251A (en) * | 2022-06-28 | 2022-09-09 | 芜湖新兴铸管有限责任公司 | Process improvement method for improving flaw detection qualification rate of high-aluminum steel |
Non-Patent Citations (2)
| Title |
|---|
| 李辉;秦晓锋;温宝利;刘世程;刘德义;: "LZ50车轴钢中的混晶组织", 大连交通大学学报, no. 03 * |
| 杨雄飞;韦青峰;: "LZ50钢车轴及钢坯的技术进展", 中国冶金, no. 01 * |
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