CN116334500A

CN116334500A - High-strength anti-fatigue elastoplastic damping steel and manufacturing method and application thereof

Info

Publication number: CN116334500A
Application number: CN202310329138.5A
Authority: CN
Inventors: 杨旗; 王敏
Original assignee: Shanghai Material Research Institute Co ltd
Current assignee: Shanghai Material Research Institute Co ltd
Priority date: 2023-03-30
Filing date: 2023-03-30
Publication date: 2023-06-27

Abstract

The invention relates to high-strength anti-fatigue elastoplastic damping steel, and a manufacturing method and application thereof, wherein the high-strength anti-fatigue elastoplastic damping steel comprises the following chemical components in percentage by mass: less than or equal to 30 percent of Mn less than or equal to 40 percent, less than or equal to 6.0 percent and less than or equal to 11.0 percent of Al less than or equal to 0.6 percent and less than or equal to 1.2 percent of C less than or equal to 0.6 percent and less than or equal to 3.0 percent of Si less than or equal to 1.0 percent, less than or equal to 1.0 percent of Cr less than or equal to 1.0 percent, less than or equal to 1.0 percent of Ti less than or equal to 1.0 percent of Nb, less than or equal to 0.15 percent of P, less than or equal to 0.03 percent of S, less than or equal to 0.03 percent of N, and the balance of Fe and unavoidable impurity elements. The elastic-plastic damping steel is manufactured by a casting, hot rolling and post-hot rolling annealing production process flow or a casting, hot rolling, solid solution and aging heat treatment production process flow, and the yield strength of the elastic-plastic damping steel is more than 420MPa; under the cyclic stretching-compressing loading condition, when the strain amplitude, the strain ratio and the loading frequency are respectively 1%, -1.0 and 0.1-0.2 Hz, the room temperature fatigue life of the steel plate is more than 2000 weeks.

Description

High-strength anti-fatigue elastoplastic damping steel and manufacturing method and application thereof

Technical Field

The invention relates to a steel material, in particular to high-strength anti-fatigue elastoplastic damping steel, and a manufacturing method and application thereof.

Background

Large scale earthquakes can cause great damage to high-rise buildings and structures. The elastic plastic steel damper placed in the building can effectively absorb external vibration energy, so that the damage to the building and the structure is reduced to the minimum. The elastic plastic steel damper realizes the absorption of vibration energy by elastic plastic hysteresis deformation of the damping unit steel under the action of external reciprocating vibration. Therefore, a damping unit steel material for dampers (hereinafter referred to as "elastoplastic damping steel") is required to have relatively stable hysteresis characteristics and good low cycle fatigue properties.

Currently, elastoplastic damping steels used to make steel dampers are typically low yield point steels and carbon structural steels with higher yield strength (e.g., Q235 and Q355B, etc.). The steel types are all ferritic steel; under the action of alternating load, fatigue damage is usually induced to form and expand from the concentrated position of internal stress and strain, resident sliding belt and dislocation cellular structure of the ferritic steel material earlier, and finally, the material is subjected to fatigue damage, so that the fatigue life of the material is often lower; further, as the strength of ferritic steel materials increases, the fatigue life of the materials upon repeated plastic deformation is also typically correspondingly reduced. Therefore, steel dampers made from the above ferritic steel materials are difficult to meet the fatigue performance requirements under some conditions of use.

The Fe-Mn-Si austenitic alloy steel with low fault energy has excellent fatigue resistance, can be used for manufacturing damping units of steel dampers, and prolongs the service life of the dampers. However, the low-fault energy Fe-Mn-Si austenitic alloy steel has a low yield strength (usually significantly lower than 350 to 400 MPa); when the damping unit needs to provide a large damping force, the design cross-sectional area of the damping unit also increases, which results in an increase in the required installation space of the damper. For some building structures (such as bridge structures) with limited installation space, steel dampers are often not designed for use or are inflexible in their spatial layout.

In view of the adverse properties of the conventional elastoplastic damping steel (low fatigue resistance of ferritic steel and low yield strength of Fe-Mn-Si austenitic alloy steel with low stacking fault energy), development of elastoplastic damping steel with higher yield strength and good fatigue resistance is urgently needed to manufacture a damping unit and a steel damper which can provide a larger damping force, have good fatigue performance and small structural size, realize miniaturization and light weight of the steel damper, and enable the steel damper to exert the energy dissipation and damping effects and enhance the installation and use flexibility of the steel damper.

Disclosure of Invention

The first aspect of the invention provides a high-strength anti-fatigue elastoplastic damping steel, the second aspect provides a manufacturing method of the high-strength anti-fatigue elastoplastic damping steel, and the third aspect provides application of the high-strength anti-fatigue elastoplastic damping steel.

The aim of the invention can be achieved by the following technical scheme:

the first aspect of the invention provides a high-strength anti-fatigue elastoplastic damping steel.

A high-strength anti-fatigue elastoplastic damping steel comprises the following chemical components in percentage by mass: less than or equal to 30 percent of Mn less than or equal to 40 percent, less than or equal to 6.0 percent and less than or equal to 11.0 percent of Al less than or equal to 0.6 percent and less than or equal to 1.2 percent of C less than or equal to 0.6 percent and less than or equal to 3.0 percent of Si less than or equal to 1.0 percent, less than or equal to 1.0 percent of Cr less than or equal to 1.0 percent, less than or equal to 1.0 percent of Ti less than or equal to 1.0 percent of Nb, less than or equal to 0.15 percent of P, less than or equal to 0.03 percent of S, less than or equal to 0.03 percent of N, and the balance of Fe and unavoidable impurity elements.

The microstructure of the high-strength anti-fatigue elastoplastic damping steel comprises austenite, ferrite with the volume fraction of not more than 10 percent and carbide with the volume fraction of not more than 10 percent.

The austenite structure has an average grain size of not more than 250 μm.

The yield strength of the high-strength anti-fatigue elastoplastic damping steel is more than 420MPa; under the cyclic stretching-compressing loading condition, when the strain amplitude, the strain ratio and the loading frequency are respectively 1%, -1.0 and 0.1-0.2 Hz, the room temperature fatigue life of the elastoplastic damping steel is more than 2000 weeks.

In one embodiment of the present invention, preferably, the high strength anti-fatigue elastoplastic damping steel comprises the following chemical components in mass percent: less than or equal to 30 percent of Mn less than or equal to 38.8 percent, less than or equal to 6.0 percent of Al less than or equal to 10.0 percent, less than or equal to 0.6 percent of C less than or equal to 0.88 percent, less than or equal to 0.62 percent of Si less than or equal to 1.50 percent, less than or equal to 1.1 percent of Cr less than or equal to 2.3 percent, less than or equal to 0.2 percent of Ti less than or equal to 0.5 percent of Nb, less than or equal to 0.5 percent of V, less than or equal to 0.15 percent of P, less than or equal to 0.03 percent of S, less than or equal to 0.03 percent of N, and the balance of Fe and unavoidable impurity elements.

In one embodiment of the present invention, it is further preferred that the high strength anti-fatigue elastoplastic damping steel comprises the following chemical components in mass percent: less than or equal to 30 percent of Mn less than or equal to 37.3 percent, less than or equal to 7.8 percent of Al less than or equal to 10.0 percent, less than or equal to 0.76 percent of C less than or equal to 0.88 percent, less than or equal to 0.62 percent of Si less than or equal to 1.50 percent, less than or equal to 1.1 percent of Cr less than or equal to 2.3 percent, less than or equal to 0.15 percent of P less than or equal to 0.03 percent of S, less than or equal to 0.03 percent of N, and the balance of Fe and unavoidable impurity elements.

In the composition design of the present invention, the functions of the respective components are as follows.

Mn: mn is the main alloying element in the present invention. Mn increases austenite stability, promotes austenite formation, and increases austenite stacking fault energy. The Mn content is increased, so that the start of a bit plane sliding mechanism in an austenitic matrix of the alloy steel is facilitated, and the fatigue resistance of the alloy steel is improved. When the Mn content is less than 30.0%, excessive ferrite phase may occur in the alloy steel, thereby affecting the low cycle fatigue life of the alloy steel; when the Mn content is higher than 40.0%, a beta-Mn brittle phase is easy to appear in the alloy steel matrix, and the toughness and fatigue resistance of the alloy steel are reduced. Therefore, the Mn content is controlled to be 30.0-40.0%.

Al: al is the main alloying element in the present invention. On one hand, the Al element can obviously increase the stacking fault energy of austenite in the steel, promote the start of a plane-positioned sliding mechanism in an austenite matrix of the alloy steel, and improve the fatigue resistance of the alloy steel; al can play a solid solution strengthening role, and the yield strength of the alloy steel is improved. On the other hand, al is a strong ferrite forming element, and the addition of excessive Al forms excessive ferrite in the matrix of the alloy steel, thereby affecting the low cycle fatigue life of the alloy steel. Further, al is a main forming element of kappa carbide in an austenite matrix, and increasing the Al content promotes the formation of kappa carbide in the austenite matrix (thereby increasing the yield strength of the alloy steel), but the presence of excessive Al and kappa carbide can rather reduce the fatigue resistance of the alloy steel (mainly expressed by that the low cycle fatigue life of the alloy steel is reduced, and the cycle peak stress in the fatigue deformation process is obviously reduced along with the increase of cycle deformation). Therefore, the Al content is controlled to be 6.0-11.0%.

C: c is the main alloying element in the present invention. On one hand, C is an important solid solution strengthening element, so that the strength of the alloy steel can be obviously improved; c is an austenite stabilizing element that promotes austenite formation. On the other hand, C is a main forming element of kappa carbide in the austenitic matrix, increasing the C content promotes kappa carbide generation in the austenitic matrix and increases the strength of the alloy steel, but the presence of excessive C and kappa carbide may instead significantly reduce the fatigue resistance of the alloy steel. Therefore, the invention controls the content of C to be 0.6-1.2%.

Si: si is an important alloying element in the present invention. On one hand, the addition of Si element can obviously improve the yield strength and work hardening rate of the alloy steel, increase the fluidity of molten steel during alloy steel smelting, further increase the manufacturability of Al-rich alloy steel, promote the start of a dislocation plane sliding mechanism in an austenitic matrix of the alloy steel, further be beneficial to improving the fatigue resistance of the alloy steel, inhibit the formation of beta-Mn brittle phase in the alloy steel, and further improve the plasticity and toughness of the alloy steel. When the Si content is less than 0.6%, the above advantageous effects are less pronounced. In addition, when Si element is contained in the alloy steel, the alloy steel can be prepared by smelting the ferromanganese alloy (less or no electrolytic manganese, which is more expensive, is used as a steelmaking raw material), which contributes to a significant reduction in the manufacturing cost of the alloy steel. On the other hand, si is a ferrite forming element, and can promote the formation and coarsening of kappa carbide in an austenitic matrix of alloy steel; the addition of excessive Si results in excessive formation and excessive coarsening of kappa carbides, which can cause excessive ferrite phase, B2 phase and DO3 phase to form in the matrix of the alloy steel, all of which can significantly impair the fatigue resistance properties of the alloy steel. When the Si content exceeds 3.0%, the above adverse effects are remarkable. Therefore, the invention defines Si content to be 0.6% < Si.ltoreq.3.0%.

Cr: cr is an important alloying element in the present invention. The addition of Cr element helps to increase the work hardening degree of the alloy steel, so that the deformation flow stress of the alloy steel can be increased, and the formation and coarsening of kappa carbide in an austenite matrix are inhibited, so that the fatigue resistance of the alloy steel is improved. However, cr element is a ferrite forming element, and the addition of excessive Cr forms excessive ferrite phase in the matrix of the alloy steel, thereby impairing the fatigue resistance of the alloy steel. Therefore, the invention limits the Cr content to be 1.0% < Cr.ltoreq.3.0%.

Ti, nb, V: ti, nb and V are strong carbide forming elements, and the elements are added to generate tiny and dispersed carbide in the matrix of the alloy steel so as to improve the yield strength of the alloy steel. However, excessive amounts of Ti, nb, V and formed carbides impair the plasticity and fatigue resistance properties of the alloy steel. The invention limits Ti less than or equal to 1.0%, nb less than or equal to 1.0%, and V less than or equal to 1.0%.

P: p increases the hot-shortness of alloy steel (especially in high Mn alloy steel), and the P content in the steel is less than or equal to 0.15 percent.

S: s causes hot shortness of steel, and in high Mn alloy steel, S can obviously increase hot shortness of steel and reduce plasticity and toughness of steel. Therefore, the S content is limited to 0.03% or less.

N: n is easy to form AlN with Al; when the N content is too high, coarse AlN particles formed affect the ductility of the steel sheet. Therefore, the N content is limited to 0.03% or less.

In one embodiment of the invention, the composition of the elastic-plastic damping steel can also contain a small amount of Cu and Ni elements under the condition of not changing the original matrix microstructure of the elastic-plastic damping steel, and the mass percentage of the two elements is not more than 3.0 percent from the aspect of alloy cost. Namely, the mass percentages of the chemical components are as follows: less than or equal to 30 percent of Mn less than or equal to 40 percent, less than or equal to 6.0 percent of Al less than or equal to 11.0 percent, less than or equal to 0.6 percent of C less than or equal to 1.2 percent, less than or equal to 0.6 percent of Si less than or equal to 3.0 percent, less than or equal to 1.0 percent of Cr less than or equal to 1.0 percent, less than or equal to 1.0 percent of Ti less than or equal to 1.0 percent of Nb, less than or equal to 0.15 percent of P, less than or equal to 0.03 percent of S, less than or equal to 0.03 percent of N, less than or equal to 3.0 percent of Cu, less than or equal to 3.0 percent of Ni, and the balance of Fe and unavoidable impurity elements.

In the invention, for the austenitic alloy steel with the alloy composition, the stretching-compressing reciprocating cyclic deformation promotes the start of a plane sliding mechanism in the alloy steel, thereby obviously improving the fatigue resistance of the alloy steel. The microstructure defining the alloy steel may include no more than 10% ferrite by volume and no more than 10% carbide by volume. When the content of ferrite phase and carbide (including kappa carbide and carbide of Ti, nb, V) in the alloy steel matrix is excessive, the fatigue life of the alloy steel may be significantly reduced. In particular, when too much κ carbide is contained in the austenite matrix, the cyclic peak stress during fatigue deformation is significantly reduced with increasing cyclic deformation cycles, and the fatigue resistance of the alloy steel is reduced.

In the present invention, the austenite is defined to have an average grain size of not more than 250 μm. When the austenite grain size is too large, fatigue cracks can be formed and expanded from austenite grain boundaries prematurely in the cyclic deformation process, thereby significantly weakening the fatigue resistance of the alloy steel.

In the invention, the alloy steel with the alloy composition and microstructure characteristics has the following mechanical properties: the yield strength of the alloy steel is more than 420MPa; under the cyclic stretching-compressing loading condition, when the strain amplitude, the strain ratio and the loading frequency are respectively 1%, -1.0 and 0.1-0.2 Hz, the room temperature fatigue life of the alloy steel is more than 2000 weeks.

In addition, in the present invention, the alloy steel having the above alloy composition has a density which is 7% or more lower than that of the conventional carbon structural steel (so that the damping unit can be reduced in weight in terms of the specific gravity of the material), and has a corrosion resistance which is remarkably improved as compared with that of the conventional carbon structural steel.

The second aspect of the invention provides two methods for manufacturing high-strength anti-fatigue elastoplastic damping steel.

The first manufacturing method of the high-strength anti-fatigue elastoplastic damping steel comprises the following steps:

1) Smelting and casting according to the following components to obtain a casting blank

The mass percentages of the chemical components are as follows: less than or equal to 30 percent of Mn less than or equal to 40 percent, less than or equal to 6.0 percent of Al less than or equal to 11.0 percent, less than or equal to 0.6 percent of C less than or equal to 1.2 percent, less than or equal to 0.6 percent of Si less than or equal to 3.0 percent, less than or equal to 1.0 percent of Cr less than or equal to 1.0 percent, less than or equal to 1.0 percent of Ti less than or equal to 1.0 percent of Nb, less than or equal to 0.15 percent of P, less than or equal to 0.03 percent of S, less than or equal to 0.03 percent of N, and the balance of Fe and unavoidable impurity elements;

2) Hot rolling

Heating a casting blank at 1000-1250 ℃ for 1-6 hours, hot-rolling the casting blank into a hot-rolled plate, wherein the hot-rolled deformation is more than or equal to 40%, and the finishing temperature is more than or equal to 800 ℃;

3) Annealing after hot rolling

Heating the hot rolled plate to a soaking temperature of 800-1100 ℃ for 0.5-5 h; and after the annealing is finished, cooling the steel plate to room temperature at a cooling rate of not less than 5 ℃/min.

In one embodiment of the present invention, it is preferable that the soaking temperature is 900 to 1000 ℃ and the soaking time is 1.0 to 1.5 hours at the time of annealing after hot rolling.

The second manufacturing method of the high-strength anti-fatigue elastoplastic damping steel comprises the following steps:

2) Hot rolling

3) Solid solution and aging heat treatment

In the solution treatment process, the hot rolled plate is heated to the soaking temperature of 1000-1180 ℃ and the soaking time is 0.5-3 h; cooling the steel plate to room temperature at a cooling rate of not less than 100 ℃/min after soaking;

in the aging treatment process, the steel plate after solution treatment is heated to the soaking temperature of 500-750 ℃ for 0.5-5 h; and after soaking, cooling the steel plate to room temperature at a cooling rate of not less than 10 ℃/min.

The reason for the design of the manufacturing process of the invention is as follows:

(1) Hot rolling process

The heating temperature is 1000-1250 ℃. When the heating temperature exceeds 1250 ℃, the cast slab is over-burned, and the grain structure in the slab is coarse, so that the hot workability is reduced; when the heating temperature is lower than 1000 ℃, after the slab is subjected to high-pressure water descaling and blooming, the finish rolling temperature is too low to cause the deformation resistance of the slab to be too high, so that the hot rolled steel plate which has no surface defect and has a specified thickness is difficult to manufacture.

The heat preservation time is 1-6 h during hot rolling. The heat preservation time is longer than 6 hours, so that the coarse grain structure in the slab can be caused; the heat preservation time is less than 1h, the non-uniformity degree of the cast structure in the slab is still higher, and the segregation is still serious.

The invention needs to control the hot rolling deformation to be not less than 40 percent so as to eliminate the internal structure non-uniformity and defects of the casting blank; the hot rolling of a cast slab is completed by controlling the finishing temperature to be more than 800 ℃, and the excessively low finishing temperature causes the deformation resistance of the slab to be excessively high, so that it is difficult to manufacture a hot rolled steel plate with a required thickness specification and without surface and edge defects.

(2) Annealing process after hot rolling

And (5) carrying out annealing heat treatment on the hot rolled steel plate. In the invention, the soaking temperature is 800-1100 ℃, and the soaking time is 0.5-5 h; and after the annealing is finished, cooling the steel plate to room temperature at a cooling rate of not less than 5 ℃/min. The process aims to eliminate hot rolling deformation structure and regulate carbide in alloy steel matrix. The annealing process conditions of the invention are closely related to the components of the steel grade alloy, and when the soaking temperature is lower than 800 ℃, the hot rolling deformation structure can not be sufficiently eliminated; when the soaking temperature is higher than 1100 ℃, austenite grains of the alloy matrix are excessively coarse, and the low-cycle fatigue life of the alloy steel at room temperature can be damaged in both cases. Therefore, the soaking temperature of annealing after hot rolling is controlled to be 800-1100 ℃. In the annealing process, the soaking time can be adjusted by properly changing the soaking temperature, and the production efficiency is affected by overlong heat preservation time, so that the soaking time is controlled to be not more than 5 hours. In one embodiment of the present invention, it is preferable that the soaking temperature is 900 to 1000 ℃ and the soaking time is 1.0 to 1.5 hours at the time of annealing after hot rolling. After the annealing, the steel plate is cooled to room temperature at a cooling rate of not less than 5 ℃/min. At cooling rates below 5 c/min, excessive and excessively coarse kappa carbides may form in the alloy steel matrix, affecting the fatigue resistance properties of the alloy steel.

(3) Solid solution and aging process after hot rolling

And carrying out solid solution aging heat treatment on the hot rolled steel plate. The solid solution and aging process conditions of the invention are closely related to the components of the steel grade alloy, and the carbide content and the size in the austenitic matrix are regulated and controlled through the solid solution and aging process, so as to obtain the matching of high strength and good fatigue performance. In the solution treatment process, the hot rolled plate is heated to the soaking temperature of 1000-1180 ℃ and the soaking time is 0.5-3 h; and after soaking, cooling the steel plate to room temperature at a cooling rate of not less than 100 ℃/min. When the solid solution temperature is lower than 1000 ℃, carbide in the hot rolled plate cannot be completely dissolved, and supersaturated solid solution cannot be effectively formed in an austenite matrix; at a solution temperature higher than 1180 ℃, austenite grains in the hot rolled sheet are too coarse. After soaking, when the cooling rate of the steel plate is lower than 100 ℃/min, the supersaturation degree of an austenite matrix can be obviously reduced, and the regulation and control of the carbide content and the size in the subsequent aging process are not facilitated.

In the aging treatment process, the steel plate after solution treatment is heated to the soaking temperature of 500-750 ℃ for 0.5-5 h; and after soaking, cooling the steel plate to room temperature at a cooling rate of not less than 10 ℃/min. When the soaking temperature is lower than 500 ℃, carbide cannot be effectively separated out from the austenitic matrix; when the soaking temperature is higher than 750 ℃, the content of precipitated carbide in the austenite matrix is excessive, and the size is excessive. After soaking, when the cooling rate of the aged steel plate is lower than 10 ℃/min, the formed carbide can be further coarsened. The austenite matrix carbides mainly refer to kappa carbides; when the alloy composition contains Ti, nb, or V, the matrix carbide also includes a carbide of Ti, nb, or V. Excessive kappa carbide can significantly reduce the low cycle fatigue properties of the alloy steel.

The invention adopts the composition design, the rolling process, the annealing process or the solid solution aging process, the matrix microstructure of the manufactured steel plate comprises austenite, ferrite with the volume fraction of not more than 10 percent and carbide with the volume fraction of not more than 10 percent, and the austenite grain size is not more than 250 mu m. During the action process of the tensile-compressive cyclic load or the shearing cyclic load, the alloy component design promotes the dislocation plane sliding mechanism to start so as to reduce the generation of crystal defects and delay the expansion of fatigue cracks, so that the material has good room temperature low cycle fatigue life. In the invention, the alloy steel with the alloy composition and microstructure characteristics has the following mechanical properties: the yield strength of the alloy steel is more than 420MPa; under cyclic stretching-compressing loading, when the strain amplitude, the strain ratio and the loading frequency are respectively 1%, -1.0 and 0.1-0.2 Hz, the room temperature fatigue life of the alloy steel is more than 2000 weeks.

A third aspect of the invention provides the use of a high strength anti-fatigue elastoplastic damping steel.

The high-strength anti-fatigue elastoplastic damping steel is used for manufacturing damping units or steel dampers for building and bridge shock absorption and insulation so as to improve the shock resistance and protection performance of the building.

Compared with the prior art, the invention has the following beneficial effects:

1. compared with the traditional ferritic steel (such as low yield point steel and carbon structural steel of Q235, Q355B and the like), the steel has obviously improved room temperature low cycle fatigue life; compared with Fe-Mn-Si austenitic alloy steel with low fault energy, the steel grade has obviously improved strength. Therefore, the steel grade has good matching of strength and fatigue resistance, and is beneficial to realizing the weight reduction and miniaturization of the damping unit and the steel damper.

2. The steel grade of the invention can be produced and prepared by using ferromanganese alloy as a raw material, and the cost of alloy steel can be reduced.

3. The elastoplastic damping steel not only has good mechanical properties, but also has the characteristics of low density and good corrosion resistance.

4. The manufacturing process related to the invention can be completed on the existing steel plate production line without major adjustment. Therefore, the invention has good popularization and application prospect.

Detailed Description

2) Hot rolling

3) Annealing after hot rolling

1) Smelting and casting according to the following components to obtain a casting blank;

2) Hot rolling

3) Solid solution and aging heat treatment

The present invention will be described in detail with reference to specific examples.

Table 1 shows the alloy compositions of the steel grades of the examples and comparative examples according to the invention, wherein the contents of S, N and P are respectively: 0.008 to 0.02 percent of S, 0.006 to 0.02 percent of N and 0.009 to 0.15 percent of P; the content of Fe element is the balance; table 2 shows the manufacturing process of the steel grades of the examples and the comparative examples of the invention; table 3 shows the microstructure and mechanical properties of the steel sheets of examples and comparative examples according to the present invention.

The content ratios of the respective components in examples 1 to 15 and comparative examples 1 to 5 were designed according to Table 1.

TABLE 1 (Unit: wt%)

The steel grades having the composition shown in table 1 were manufactured into slabs after smelting and casting. Heating the slab at 1200 ℃, carrying out hot rolling on the slab after the heat preservation time is 2 hours, and finishing hot rolling at the finishing temperature of 860 ℃ to obtain a hot rolling finish rolling, wherein the accumulated deformation of the hot rolling is more than 40%.

And (3) after the hot rolled steel plate is subjected to annealing process or solid solution aging process treatment (specific process conditions are shown in table 2), cooling to room temperature, and thus obtaining the target damping steel plate.

TABLE 2

The microstructure and mechanical properties of the steel sheets of examples 1 to 15 and comparative examples 1 to 5 of the present invention are shown in Table 3. In Table 3, if ferrite and carbide are contained in the matrix of all the example steel grades, the volume fraction of ferrite is not more than 10%, and the volume fraction of carbide is not more than 10%. The test conditions for the low cycle fatigue life at room temperature were: the strain amplitude, strain ratio and loading frequency are respectively 1%, -1.0 and 0.1-0.2 Hz.

TABLE 3 Table 3

As can be seen from Table 3, the invention can obtain the high-strength anti-fatigue elastoplastic damping steel plate with yield strength more than 420MPa through reasonable composition and process design; under cyclic stretching-compressing loading, when the strain amplitude, the strain ratio and the loading frequency are respectively 1%, -1.0 and 0.1-0.2 Hz, the room temperature fatigue life of the alloy steel is more than 2000 weeks.

The previous description of the embodiments is provided to facilitate a person of ordinary skill in the art in order to make and use the present invention. It will be apparent to those skilled in the art that various modifications can be readily made to these embodiments and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above-described embodiments, and those skilled in the art, based on the present disclosure, should make improvements and modifications without departing from the scope of the present invention.

Claims

1. The high-strength anti-fatigue elastoplastic damping steel is characterized by comprising the following chemical components in percentage by mass: less than or equal to 30 percent of Mn less than or equal to 40 percent, less than or equal to 6.0 percent and less than or equal to 11.0 percent of Al less than or equal to 0.6 percent and less than or equal to 1.2 percent of C less than or equal to 0.6 percent and less than or equal to 3.0 percent of Si less than or equal to 1.0 percent, less than or equal to 1.0 percent of Cr less than or equal to 1.0 percent, less than or equal to 1.0 percent of Ti less than or equal to 1.0 percent of Nb, less than or equal to 0.15 percent of P, less than or equal to 0.03 percent of S, less than or equal to 0.03 percent of N, and the balance of Fe and unavoidable impurity elements.

2. The high strength fatigue resistant elastoplastic damping steel of claim 1, wherein the microstructure of the elastoplastic damping steel comprises austenite, no more than 10% ferrite by volume fraction, and no more than 10% carbide by volume fraction.

3. The high strength fatigue resistant elastoplastic damping steel of claim 2, wherein the austenite has an average grain size of no more than 250 μιη.

4. The high strength fatigue resistant elastoplastic damping steel of claim 1, wherein the yield strength of the elastoplastic damping steel is > 420MPa; under the cyclic stretching-compressing loading condition, when the strain amplitude, the strain ratio and the loading frequency are respectively 1%, -1.0 and 0.1-0.2 Hz, the room temperature fatigue life of the elastoplastic damping steel is more than 2000 weeks.

5. The high strength anti-fatigue elastoplastic damping steel according to any of claims 1-4, wherein the high strength anti-fatigue elastoplastic damping steel comprises the following chemical components in mass percent: less than or equal to 30 percent of Mn less than or equal to 38.8 percent, less than or equal to 6.0 percent of Al less than or equal to 10.0 percent, less than or equal to 0.6 percent of C less than or equal to 0.88 percent, less than or equal to 0.62 percent of Si less than or equal to 1.50 percent, less than or equal to 1.1 percent of Cr less than or equal to 2.3 percent, less than or equal to 0.2 percent of Ti less than or equal to 0.5 percent of Nb, less than or equal to 0.5 percent of V, less than or equal to 0.15 percent of P, less than or equal to 0.03 percent of S, less than or equal to 0.03 percent of N, and the balance of Fe and unavoidable impurity elements.

6. The high-strength anti-fatigue elastoplastic damping steel according to claim 5, wherein the high-strength anti-fatigue elastoplastic damping steel comprises the following chemical components in percentage by mass: less than or equal to 30 percent of Mn less than or equal to 37.3 percent, less than or equal to 7.8 percent of Al less than or equal to 10.0 percent, less than or equal to 0.76 percent of C less than or equal to 0.88 percent, less than or equal to 0.62 percent of Si less than or equal to 1.50 percent, less than or equal to 1.1 percent of Cr less than or equal to 2.3 percent, less than or equal to 0.15 percent of P less than or equal to 0.03 percent of S, less than or equal to 0.03 percent of N, and the balance of Fe and unavoidable impurity elements.

7. A method for manufacturing a high strength anti-fatigue elastoplastic damping steel according to any of claims 1-4, comprising the steps of:

2) Hot rolling

3) Annealing after hot rolling

8. The method for producing high-strength fatigue-resistant elastoplastic damping steel according to claim 7, wherein the soaking temperature is 900-1000 ℃ and the soaking time is 1.0-1.5 h at the time of annealing after hot rolling.

9. A method for manufacturing a high strength anti-fatigue elastoplastic damping steel according to any of claims 1-4, comprising the steps of:

2) Hot rolling

3) Solid solution and aging heat treatment

10. The use of a high strength anti-fatigue elastoplastic damping steel according to any of claims 1-4 for manufacturing damping units or steel dampers for shock absorption and insulation of buildings and bridges.