CN112662942B - Damping steel and preparation method thereof - Google Patents
Damping steel and preparation method thereof Download PDFInfo
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- CN112662942B CN112662942B CN202011306104.7A CN202011306104A CN112662942B CN 112662942 B CN112662942 B CN 112662942B CN 202011306104 A CN202011306104 A CN 202011306104A CN 112662942 B CN112662942 B CN 112662942B
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Abstract
The invention discloses damping steel and a preparation method thereof, and the damping steel comprises the following components in percentage by mass: less than or equal to 0.015%, Si: 0.1-0.3%, Mn: 0.6-2.5%, P: less than or equal to 0.01 percent, S: 0.15 to 0.55%, Al: 0.01% -0.03%, [ N ]: not more than 0.01%, and [ O ]: 0.002-0.005%, Mg: 0.001 to 0.003%, and the balance Fe and inevitable impurities. The steel obtains excellent damping performance by adding a certain amount of Mg element and S element, and has excellent cutting performance and mechanical property.
Description
Technical Field
The invention relates to steel and a preparation method thereof, in particular to damping steel and a preparation method thereof.
Background
Due to the development of the industry, the demands for vibration and noise reduction are more and more prominent. For structures, vibrations mainly cause structural fatigue, noise and vibrations. Since vibration and noise reduction by means of increasing the weight and volume of the system, improving the structural design, etc., increases the weight of the components, it has become very important to know the vibration and noise from the source. Damping alloys have therefore been developed. The damping alloy has excellent damping performance and mechanical performance, so that the damping alloy has wide application in the aspects of aerospace, military industry, automobiles, construction, ocean engineering and the like. Physical parameters for representing the damping performance of the material mainly comprise Bidamping SDC, a damping loss factor tan delta, a logarithmic decrement delta and an internal loss value Q-1, and the alloy with the SDC larger than 20% or the tan delta larger than 0.03 is generally considered to be the high-damping alloy.
The Fe-Mn alloy is a novel damping alloy, has the highest strength and lower price in several damping alloys (Mn-Cu base, Mg base, Ni-Ti base and Zn-Al base), and the damping performance of the Fe-Mn alloy is increased along with the increase of strain amplitude. The Fe-Mn-based alloy is very suitable for manufacturing mechanical equipment and parts which bear large vibration and impact. According to the damping mechanism, the damping alloy can be classified into a complex phase type damping alloy (gray cast iron and Zn-Al alloy), a dislocation type damping alloy (Mg-based), a twin crystal type damping alloy (Mn-Cu, Ni-Ti), a ferromagnetic type damping alloy (Fe-Cr-based, Fe-Co-based, Fe-Al-based, and Co-Ni-based alloys). For Fe-Mn damping alloy, the damping mechanism is not studied thoroughly, and the only researchers believe that the main damping sources of the alloy include: (1) movement of the gamma/epsilon phase interface; (2) movement of epsilon-body variable interfaces; (3) movement of stacking faults in austenite; (4) movement of stacking faults in epsilon martensite.
The damping mechanism of the Fe-Mn damping alloy is still under study at present, but most researchers think that the damping performance of the Fe-Mn damping alloy is related to the epsilon martensite in the alloy, and the Seung-Han Baik et al in Korea points out that the key factor influencing the damping performance of the Fe-Mn damping alloy is the quantity and the form of the epsilon martensite. And in the Fe-Mn binary alloy, the damping performance is best when the Mn content is 17 percent.
Chinese patent CN 106282786A, "Nb-containing iron-manganese-based damping alloy and preparation method thereof", proposes an Nb-containing iron-manganese-based damping alloy, the mass fraction of which is 17% of Mn, 0.1-1% of Nb and the balance of Fe. And controlling the Mn element to be 17% to improve the damping performance, and simultaneously adding the Nb element into the steel.
Chinese patent CN 106011636A, "a marine iron-manganese-based high-toughness damping alloy", comprises the following chemical components in percentage by weight: less than or equal to 0.02 percent of carbon, less than or equal to 0.02 percent of silicon, 16.5 to 17.5 percent of manganese, less than or equal to 0.005 percent of sulfur, less than or equal to 0.01 percent of phosphorus, less than or equal to 0.01 percent of nitrogen, less than or equal to 0.015 percent of aluminum, and the balance of iron. The manganese content in the steel is mainly controlled to be 16.5-17.5%.
Chinese patent CN 107338401A 'a Nb-containing composite low-alloy damping steel and a preparation method thereof' the requirements of the chemical components in percentage by weight are as follows: less than or equal to 0.15 percent of C, less than or equal to 0.2 percent of Si, 0.5-2.0 percent of Mn, 0.2-0.6 percent of S, 0.01-0.06 percent of Nb and the balance of: fe. The damping performance is improved by adding Nb element into steel.
At present, the addition elements of the Fe-Mn damping alloy mainly comprise C, N, Ti, Co, Ni and Cr, and related research and report of adding Mg element into steel are not provided.
Disclosure of Invention
The purpose of the invention is as follows: the invention aims to provide damping steel which has excellent damping performance and has excellent cutting performance and mechanical property.
The invention also aims to provide a preparation method of the damping steel.
The technical scheme is as follows: the damping steel comprises the following components in percentage by mass: less than or equal to 0.015%, Si: 0.1-0.3%, Mn: 0.6-2.5%, P: less than or equal to 0.01 percent, S: 0.15 to 0.55%, Al: 0.01% -0.03%, [ N ]: not more than 0.01%, and [ O ]: 0.002-0.005%, Mg: 0.001 to 0.003%, and the balance Fe and inevitable impurities.
Wherein the Mn/S ratio in the steel composition is 3.0-5.0.
A certain amount of Mg element is added in the component design of the steel, and the mechanism is that fine dispersion oxide is formed through the Mg element, the effect of oxide metallurgy is exerted, intragranular ferrite is formed through induction, crystal grains are refined, and crystal boundary is increased. In addition, the finely dispersed oxide promotes the precipitation of sulfides on the oxide to form more complex sulfides. More phase interfaces and crystal interfaces exist between the composite inclusions which are dispersed and distributed and the matrix. When elastic or plastic deformation occurs under the action of external force, the phase interface and the crystal boundary surface become the main energy absorption area, more phase interfaces and crystal interfaces can absorb a large amount of energy generated by vibration, point defects and line defects are easily formed at the interface due to the difference of two phases, and the interaction between the defects can consume a large amount of vibration energy, so that the internal consumption of the material is increased. The damping performance is improved by increasing the defects of crystal boundary, interface between dispersed inclusions and structure and the like. Meanwhile, MnS inclusions wrapped at the periphery can be softened in the cutting process to form accumulated cutting edges, so that the cutter is protected, and the cutting performance of the product is improved. Specifically, the functions of the elements are as follows:
carbon is the most important element affecting the structure in steel, and an increase in the carbon content strengthens the alloy. Carbon, however, can significantly increase the shear resistance at martensitic transformation, strongly lowering the Ms temperature. Meanwhile, the carbon content is increased, and carbon is used as interstitial atoms to play a strong pinning role in a martensite interface damping source. The damping performance of the material is not beneficial, and the content of carbon is controlled to be not higher than 0.15 percent in order to ensure the damping performance and the mechanical property of the steel.
Silicon respectively increases the probability of stacking faults and the number of Shockley incomplete dislocations in gamma austenite and epsilon martensite in steel, but the atomic radius of Si atoms is small, so that great lattice distortion is caused, a plurality of vacancy defects are generated, the Shockley incomplete dislocation is difficult to move, and the damping performance of the alloy is reduced; in addition, silicon can solid-solution strengthen the steel matrix, and therefore, the content of silicon should be controlled to 0.1 to 0.3%.
Part of manganese is combined with S element in steel, MnS inclusion taking magnesium aluminate spinel as a core is formed under the action of Mg element, and intragranular ferrite is formed. Comprehensively considering, the content of manganese should be controlled within 0.6-2.5%.
Phosphorus is a ferrite phase region forming element, can be in limited solid solution with alpha-Fe, reduces an austenite phase region, is easy to form regional segregation in steel and is not beneficial to the damping performance of the material; in addition, since an excessively high content of phosphorus deteriorates weldability and decreases toughness of the material, the content of phosphorus should be controlled to 0.01% or less.
Aluminum, oxygen and magnesium form fine and dispersed magnesium aluminate spinel, the periphery of the magnesium aluminate spinel is wrapped by softer MnS, grain refinement is facilitated, damping performance is improved, and meanwhile, the composite sulfide is beneficial to improving cutting performance. In addition, the combination of aluminum and magnesium improves the form of sulfides, converts the second type of sulfides into the first type of sulfides, and reduces the pitting corrosion caused by inclusions. Therefore, the content of aluminum is controlled to be 0.01-0.03%.
The sulfur element can improve the processing property of the steel, and simultaneously, by controlling Mn/S and added magnesium and utilizing the oxide metallurgy principle, the in-crystal ferrite is formed, the crystal grains are refined, and the damping property of the steel is improved. Therefore, the lower the sulfur content, the better, the sulfur content should be controlled to be 0.15% -0.55%.
Nitrogen easily forms second phase particles in steel, the motion resistance of extended dislocation can be increased, and the influence of a small amount of nitrogen on the damping performance of the material is small; however, when the content of nitrogen in steel is high, the two-phase particles make the movement of extended dislocation difficult, thereby reducing the damping performance of the material, and under the condition of large strain, the influence of the content of nitrogen is particularly obvious, so the content of nitrogen in steel should be controlled below 0.01%.
Magnesium can form MgO-Al with fine size, stable components and dispersed distribution in high-temperature molten steel2O3The inclusion provides a heterogeneous nucleation point for ferrite transformation. This is because MgO. Al2O3The Mg vacancy exists in the acicular ferrite, so that Mn element can be absorbed, poor Mn appears around the Mn element, and the nucleation of the acicular ferrite is promoted. The function of refining grains is achieved. Therefore, magnesium can refine grains and increase the density of grain boundaries, the grain boundaries are particularly sensitive to temperature, and the grain boundaries can slide together with dislocations at high temperature, and energy loss, namely grain boundary damping, is caused by viscous flow of the grain boundaries, so that the damping performance can be effectively improved by adding Mg. More Mg increases the steel cost, and therefore, considering the improvement of damping performance and cost of Mg, the Mg content in the present invention is 0.001% to 0.003%.
Corresponding to the damping steel, the technical scheme adopted by the preparation method provided by the invention comprises the following steps:
(1) under the protection of argon, carrying out induction heating on the raw materials at 1600 +/-10 ℃ to completely melt the raw materials, and controlling other elements except Mg to meet the target requirements of component design;
(2) adding Si-Mg alloy according to the component design proportion to adjust Mg element to reach the target requirement, fully stirring, melting and uniformly mixing;
(3) and (5) casting to form a blank.
Has the advantages that: the damping steel is a composite damping alloy mainly based on a composite phase, the material structure mainly comprises intragranular ferrite with fine MnS as a core, and MnS and cementite are arranged at a grain boundary to form a second phase different from the matrix ferrite structure. Because of MnS and cementite at the grain boundary, the ferrite takes fine MnS as a core to form intragranular ferrite, so that the grains are refined, and the grain boundary is increased. Compared with a single-phase structure, more phase interfaces and grain boundary surfaces exist, when elastic or plastic deformation occurs under the action of external force, the phase interfaces and the grain boundary surfaces become main energy absorption areas, more phase interfaces and grain boundary surfaces can absorb a large amount of energy generated by vibration, point defects and line defects are easily formed at the interfaces due to the difference of two-phase structures, interaction among the defects can consume a large amount of vibration energy, and the effects cause the increase of internal consumption of materials, so that the steel has excellent damping performance. Meanwhile, MnS inclusions wrapped at the periphery can be softened in the cutting process to form accumulated cutting edges, so that the cutter is protected, and the cutting performance of the product is improved.
Drawings
FIG. 1 is a gold phase diagram of a sample of example 1 of the present invention;
FIG. 2 is a gold phase diagram of a sample of example 2 of the present invention;
FIG. 3 is a metallographic image of a comparative example;
FIG. 4 is a graph comparing damping performance of samples of examples of the present invention and comparative examples;
FIG. 5 is a graph showing the damping performance of samples of examples 3-5 of the present invention.
Detailed Description
The following will specifically explain the technical effects of the present invention by referring to examples and comparative examples. The ingredients of each case are shown in table 1.
TABLE 1 EXAMPLES AND COMPARATIVE EXAMPLES chemical Components TABLE (wt%)
The preparation method of the two above examples is as follows:
(1) adding raw materials into a vacuum induction furnace, and containing the raw materials by adopting a magnesium oxide crucible;
(2) induction heating to 1600 +/-10 ℃, preserving heat for 30 minutes under the protection of argon to completely melt, and controlling other elements except Mg element to reach the target requirement after melting;
(3) then adding Si-Mg alloy to adjust the content of Mg to reach the content shown in the table 1, fully stirring and preserving heat for 10 minutes;
(4) then carrying out iron mold or sand mold casting; cooling to room temperature, demolding and cleaning the surface of the casting blank.
The comparative example was prepared in a similar manner to the example except that the comparative example did not incorporate the Si-Mg alloy.
And carrying out metallographic phase grain size detection and damping performance detection on the samples obtained in the three cases. As shown in fig. 1 to 3, the metallographic structure of the samples of examples and comparative examples was measured to be ferrite + pearlite after corrosion. However, in the comparative example, the grain size is significantly finer at room temperature because Mg is added. As shown in FIG. 4, the damping performance of the sample is significantly improved after Mg is added.
Meanwhile, in order to verify that the effect can be achieved within the limited range of the invention, a plurality of groups of embodiments are additionally provided, and the specific components are as follows:
table 2 examples chemical composition table (wt%)
The preparation methods adopted in the above three groups of examples are also the same as those of examples 1 and 2.
Samples of the three sets of examples described above were tested and also had excellent damping properties as shown in fig. 5.
Claims (7)
1. The damping steel is characterized by comprising the following components in percentage by mass: less than or equal to 0.015%, Si: 0.1-0.3%, Mn: 0.6-2.5%, P: less than or equal to 0.01 percent, S: 0.15 to 0.55%, Al: 0.01% -0.03%, [ N ]: not more than 0.01%, and [ O ]: 0.002-0.005%, Mg: 0.001 to 0.003%, and the balance Fe and inevitable impurities, wherein Mn/S in the composition is 3.0 to 5.0.
2. The damping steel according to claim 1, wherein the metallographic structure is pearlite and intragranular ferrite.
3. The damping steel according to claim 2, wherein the intragranular ferrite is centered on fine MnS, and MnS and cementite are distributed at grain boundaries to form a second phase.
4. Damping steel according to claim 1, characterized in that the structure of the steel contains finely dispersed MgO2O3And (4) inclusion.
5. A method for producing damping steel according to any one of claims 1 to 4, characterised in that it comprises the following steps:
(1) under the protection of argon, carrying out induction heating on the raw materials at 1600 +/-10 ℃ to completely melt the raw materials, and controlling other elements except Mg to meet the target requirements of component design;
(2) adding Si-Mg alloy according to the component design proportion to adjust Mg element to reach the target requirement, fully stirring, melting and uniformly mixing;
(3) and (5) casting to form a blank.
6. The preparation method according to claim 5, wherein in the step (1), a magnesium oxide crucible is used for containing raw material steel, and the raw material steel is added into a vacuum induction furnace for heating.
7. The method according to claim 5, wherein in the step (3), the blank is formed by die casting, and is released after being cooled to room temperature.
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1113660A (en) * | 1993-08-16 | 1995-12-20 | 新日本制铁株式会社 | Steel containing ultrafine oxide inclusions dispersed therein |
| JP2006249457A (en) * | 2005-03-08 | 2006-09-21 | Jfe Bars & Shapes Corp | Bn free-cutting steel |
| CN105658829A (en) * | 2013-10-22 | 2016-06-08 | 株式会社神户制钢所 | Hot-rolled steel sheet having excellent surface hardness after carburizing heat treatment and excellent cold workability |
| CN105671434A (en) * | 2016-03-19 | 2016-06-15 | 上海大学 | Magnesium, calcium and sulfur containing 20MnCr free-cutting gear steel and preparation method thereof |
| CN105755394A (en) * | 2016-05-24 | 2016-07-13 | 江苏金基特钢有限公司 | Corrosion-resistant easy-to-shape special steel and processing method thereof |
| CN106756498A (en) * | 2016-12-21 | 2017-05-31 | 钢铁研究总院 | A kind of method that magnesium is added in high input energy welding steel |
| CN107641769A (en) * | 2017-09-21 | 2018-01-30 | 四川大学 | Iron-based composite alloy of wide strain amplitude high-damping and preparation method thereof |
| JP2018145497A (en) * | 2017-03-07 | 2018-09-20 | 日新製鋼株式会社 | FERRITIC STAINLESS STEEL EXCELLENT IN Cu BRAZABILITY |
| CN111254364A (en) * | 2018-11-30 | 2020-06-09 | 泰州市淳强不锈钢有限公司 | Alloy steel with high strength and high wear resistance |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3956596B2 (en) * | 2000-09-14 | 2007-08-08 | Ｊｆｅスチール株式会社 | Non-oriented electrical steel sheet |
| KR101105007B1 (en) * | 2003-12-23 | 2012-01-16 | 주식회사 포스코 | Cold rolled steel sheet having excellent baking hardenability and process for producing the same |
| JP5186753B2 (en) * | 2006-02-21 | 2013-04-24 | Ｊｆｅスチール株式会社 | Damping alloy sheet and manufacturing method thereof |
| JP4998672B2 (en) * | 2006-02-21 | 2012-08-15 | Ｊｆｅスチール株式会社 | Manufacturing method of damping alloy sheet |
| KR101139605B1 (en) * | 2007-04-06 | 2012-04-27 | 신닛뽄세이테쯔 카부시키카이샤 | Steel material having excellent high temperature properties and excellent toughness, and method for production thereof |
| JP5609786B2 (en) * | 2010-06-25 | 2014-10-22 | Ｊｆｅスチール株式会社 | High-tensile hot-rolled steel sheet excellent in workability and manufacturing method thereof |
| WO2015064128A1 (en) * | 2013-10-31 | 2015-05-07 | Ｊｆｅスチール株式会社 | Ferrite-martensite two-phase stainless steel exhibiting low-temperature toughness, and method for producing same |
| CN111748735A (en) * | 2020-06-22 | 2020-10-09 | 武汉钢铁有限公司 | Band steel with excellent low-temperature secondary processing performance and tensile strength of 390MPa and production method thereof |
-
2020
- 2020-11-19 CN CN202011306104.7A patent/CN112662942B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1113660A (en) * | 1993-08-16 | 1995-12-20 | 新日本制铁株式会社 | Steel containing ultrafine oxide inclusions dispersed therein |
| JP2006249457A (en) * | 2005-03-08 | 2006-09-21 | Jfe Bars & Shapes Corp | Bn free-cutting steel |
| CN105658829A (en) * | 2013-10-22 | 2016-06-08 | 株式会社神户制钢所 | Hot-rolled steel sheet having excellent surface hardness after carburizing heat treatment and excellent cold workability |
| CN105671434A (en) * | 2016-03-19 | 2016-06-15 | 上海大学 | Magnesium, calcium and sulfur containing 20MnCr free-cutting gear steel and preparation method thereof |
| CN105755394A (en) * | 2016-05-24 | 2016-07-13 | 江苏金基特钢有限公司 | Corrosion-resistant easy-to-shape special steel and processing method thereof |
| CN106756498A (en) * | 2016-12-21 | 2017-05-31 | 钢铁研究总院 | A kind of method that magnesium is added in high input energy welding steel |
| JP2018145497A (en) * | 2017-03-07 | 2018-09-20 | 日新製鋼株式会社 | FERRITIC STAINLESS STEEL EXCELLENT IN Cu BRAZABILITY |
| CN107641769A (en) * | 2017-09-21 | 2018-01-30 | 四川大学 | Iron-based composite alloy of wide strain amplitude high-damping and preparation method thereof |
| CN111254364A (en) * | 2018-11-30 | 2020-06-09 | 泰州市淳强不锈钢有限公司 | Alloy steel with high strength and high wear resistance |
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