CN211080780U - A corrosion-resistant titanium-steel composite rebar - Google Patents

Abstract

The utility model discloses a corrosion-resistant titanium-steel composite steel bar. The corrosion-resistant titanium-steel composite reinforcing bar includes a carbon steel core and a titanium coating wrapped on the surface of the carbon steel core, and the carbon steel core is metallurgically bonded to the titanium coating. The corrosion-resistant titanium-steel composite steel bar provided by the utility model has excellent anti-corrosion performance, especially the corrosion resistance of chloride ions in the marine environment far exceeds that of stainless steel bars; and the mechanical properties are close to ordinary carbon steel. The steel bar adopts a composite structure, which can save precious metal resources and reduce costs.

Description

A corrosion-resistant titanium-steel composite rebar

technical field

The utility model relates to the technical field of bimetal composite materials, in particular to a corrosion-resistant titanium-steel composite steel bar.

Background technique

With the development of my country's marine economy and the construction needs of remote islands, the demand for reinforced concrete projects on offshore islands and reefs has increased. The development of the ocean in my country has entered a golden age, but the harsh marine environment makes the concrete structures recognized as having strong durability often lead to premature failure due to insufficient durability, which seriously restricts the development of my country's marine economy.

Rebar is an important raw material of reinforced concrete. At present, steel bars are produced by carbon steel materials. Corrosion of steel bars is one of the main reasons for the failure of durability of reinforced concrete structures. In the marine environment, chloride ion erosion is the most important factor causing corrosion of steel bars. The chloride ions in seawater and sea sand react chemically with the steel bars, causing the steel bars to corrode and expand along the bars and causing cracks in the concrete, reducing the durability and design life of the concrete structure.

In order to improve the corrosion resistance of construction projects in coastal areas and sea-island coastal defense projects, measures should be taken to overcome the corrosion of carbon steel bars in seawater and environments where snow melting salt is often used. The technical measures adopted in the prior art mainly include: the use of coated steel bars or special steel bars such as stainless steel bars.

The construction of epoxy-coated steel bars is complicated, and the anti-corrosion effect largely depends on the construction quality control, which limits its large-scale application. The corrosion resistance of stainless steel bars is much higher than that of ordinary steel bars, but the yield strength of stainless steel bars is low and expensive. In actual use, the reinforcement ratio must be increased to ensure the strength. This method is costly.

In view of this, it is necessary to provide a new steel structure to solve the above technical problems.

Utility model content

The technical problem to be solved by the utility model is to provide a corrosion-resistant titanium-steel composite steel bar with excellent anti-corrosion performance and close mechanical properties to ordinary carbon steel; the steel bar adopts a composite structure, which can save precious metal resources and reduce costs.

In order to solve the above-mentioned problems, the technical scheme of the present utility model is as follows:

A corrosion-resistant titanium-steel composite reinforcing bar comprises a carbon steel core and a titanium cladding wrapped on the surface of the carbon steel core, wherein the carbon steel core is metallurgically bonded to the titanium cladding.

Further, the corrosion-resistant titanium-steel composite rebar is a ribbed rebar or a smooth round rebar.

Further, the material of the carbon steel core is selected from low carbon steel or low alloy steel.

Further, the thickness of the titanium coating is 0.2-1 mm.

Further, the carbon steel core is made of carbon steel bar as a raw material, the titanium cladding is made of a titanium tube, and the carbon steel bar and the titanium tube are assembled and prepared by a hot rolling process to form the resistant material. Corrosion of titanium-steel composite rebar.

Further, the cross-sectional shape of the titanium tube and the carbon steel bar is the same.

Further, the cross-sectional shape of the carbon steel bar is square or circular, and the cross-sectional shape of the titanium tube is correspondingly square or circular.

Further, the side length or outer diameter of the cross-section of the carbon steel bar is 120-180mm.

Further, the length of the carbon steel bar is 3-12m.

Compared with the prior art, the corrosion-resistant titanium-steel composite steel bar provided by the utility model has the beneficial effects of:

The corrosion-resistant titanium-steel composite steel bar provided by the utility model, by coating the surface of the ordinary steel bar with a titanium coating, makes the coated steel bar have better anticorrosion performance, thereby ensuring that the reinforced concrete has excellent resistance to marine chloride corrosion. ; And the main material of the composite steel bar is carbon steel, so that the composite steel bar has the same mechanical properties as the ordinary steel bar, which can ensure that the reinforced concrete has high compressive strength, tensile strength and yield strength without the need for additional reinforcement. quantity.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments. Obviously, the drawings in the following description are only some implementations of the present invention. For example, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without any creative effort.

Fig. 1 is the structural representation of an embodiment of the corrosion-resistant titanium-steel composite reinforcing bar provided by the present utility model;

2 is a schematic structural diagram of another embodiment of the corrosion-resistant titanium-steel composite reinforcing bar provided by the present utility model;

Fig. 3 is the structural representation of the composite billet in the present utility model;

Fig. 4 is a kind of structural schematic diagram of the composite steel billet shown in Fig. 3;

FIG. 5 is another structural schematic diagram of the composite steel billet shown in FIG. 3 .

Detailed ways

In order to enable those skilled in the art to better understand the technical solutions in the embodiments of the present invention, and to make the above objects, features and advantages of the present invention more clearly understood, the following describes the specific implementation of the present invention with reference to the accompanying drawings. for further explanation.

It should be noted here that the description of these embodiments is used to help the understanding of the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as there is no conflict with each other.

Please refer to FIG. 1 and FIG. 2 in conjunction, wherein FIG. 1 is a schematic structural diagram of an embodiment of the corrosion-resistant titanium-steel composite reinforcing bar provided by the present utility model; FIG. 2 is the corrosion-resistant titanium-steel composite reinforcing bar provided by the present invention. A schematic diagram of the structure of another embodiment. The corrosion-resistant titanium-steel composite rebar 100 of the present invention includes a carbon steel core 11 and a titanium coating 12 wrapped around the surface of the carbon steel core 11 , wherein the carbon steel core 11 and the titanium coating 12 are metallurgically bonded. The corrosion-resistant titanium-steel composite steel bar 100 may be a ribbed steel bar (as shown in FIG. 1 ) or a smooth round steel bar (as shown in FIG. 2 ).

In the present invention, the carbon steel core 11 is obtained by selecting carbon steel bar material through surface treatment, and the carbon steel bar material used can be threaded steel bar or smooth round steel bar. The carbon steel bar material used in the carbon steel core 11 is low carbon steel or low alloy steel, such as HRB400, HRB400E, HRB500, HRB500E and other grades for rolling rebar, and HPB300 and other grades for rolling round steel.

The length of the carbon steel bar is 3-12m, the cross-sectional shape is round or square, and the corresponding outer diameter or side length is 120-180mm, which is determined according to the design requirements.

In the present invention, the titanium coating layer 12 is formed by using titanium material; preferably, the titanium coating layer 12 is prepared and formed by a seamless titanium tube; specifically, the titanium tube is sleeved outside the carbon steel bar, and then the hot rolling process is carried out. form. After the hot rolling process, the titanium cladding layer 12 is metallurgically bonded to the carbon steel core 11, and the thickness of the formed titanium cladding layer 12 is 0.2-1 mm. The material of the seamless titanium tube can be pure titanium tube or titanium alloy tube.

The cross-sectional shape of the titanium tube used in the titanium coating 12 is consistent with the cross-sectional shape of the carbon rod and bar, and corresponds to the cross-sectional shape of the carbon steel bar listed above. The length of the steel bar is the same, 3-12m, which is determined according to the design requirements. In the production and preparation process, the seamless titanium tube needs to be directly sleeved on the surface of the carbon steel core, and there is a certain gap between the two, specifically, the gap is 0.1-2mm.

The utility model also provides a preparation method of corrosion-resistant titanium-steel composite reinforcing bar, the preparation method comprises the following steps:

Step S1, providing carbon steel bar stock 21, and performing surface treatment on it;

Specifically, the oxide scale on the surface of the carbon steel bar 21 is removed by one of shot peening, pickling or machining.

Step S2, providing the titanium tube 22, and performing surface treatment on its inner surface;

Specifically, the titanium tube is made of seamless titanium tube, and the inner surface of the titanium tube is subjected to a descaling process by shot peening or pickling process.

Step S3, the carbon steel bar is assembled into the inner hole of the titanium tube to form a composite billet 200, the composite billet 200 is subjected to vacuum treatment, and both ends of the composite billet are welded and sealed with titanium plates 23 in a vacuum environment, so that the carbon steel bar is sealed. The gap with the titanium tube forms a closed vacuum environment;

Specifically, in the composite billet, the gap formed between the carbon steel bar and the titanium tube is 0.1-2mm; in the vacuum treatment stage, the composite billet is put into a vacuum chamber to be evacuated, and the vacuum degree is not less than 0.001Pa; When welding and sealing, a titanium plate is laid on the end respectively, and the titanium plate 23 and the titanium tube 22 are welded, so that there is no gap between the titanium tube 22 and the titanium plate 23, so that the carbon steel bar and the titanium tube are not separated. The gap forms a closed vacuum environment. For the specific structure, please refer to FIGS. 3 to 5 , wherein FIG. 3 is a schematic structural diagram of the composite steel billet in the present invention; FIG. 4 is a structural schematic diagram of the composite steel billet shown in FIG. 3 ; Another schematic diagram of the structure; wherein the composite billet shown in Figure 4 is a composite round billet, and the composite billet shown in Figure 5 is a composite square billet.

Step S4, heating the composite steel billet 200 to 980-1100°C in a weakly oxidizing atmosphere or under the protection of an inert gas, and the heating time is 3-5h;

Through the specific heating temperature and heating time, the temperature inside and outside the composite billet can be ensured to be uniform, so that the crystal phase at the bonding interface is uniform.

Wherein, when in a weakly oxidizing atmosphere, the oxygen volume content of the weakly oxidizing atmosphere is less than or equal to 5%.

Step S5, hot rolling to obtain corrosion-resistant titanium-steel composite reinforcing bars.

Specifically, the heated composite steel billet is hot-rolled by using the existing hot-rolling process, and the specific process steps are not repeated here.

In this embodiment, according to the core and cladding materials of the clad steel billet 200 , the start rolling temperature of the hot rolling process is controlled to be 950-1050°C, and the final rolling temperature is controlled to be 850-950°C.

The corrosion-resistant titanium-steel composite rebar obtained by the hot rolling process includes a carbon steel core formed from a carbon steel bar and a titanium cladding layer formed from a titanium tube, wherein the thickness of the titanium cladding layer is 0.2-1 mm.

The corrosion-resistant-steel composite reinforcement bar provided by the present invention and the preparation method thereof will be described in detail below through specific embodiments.

Example 1

In this embodiment, pure titanium tube and HRB400 round billet are used for compounding, and finally rolled into a bimetallic threaded steel bar with a diameter of Φ25mm. Please refer to FIG. 3 and FIG. 4 in combination, the selected carbon steel bar 21 and the titanium tube 22 forming the titanium cladding are all circular structures.

In this embodiment, the titanium tube is made of pure titanium, and its specific size is Φ150mm×5mm×6m (outer diameter×wall thickness×length); the carbon steel bar 21 of the core is the blank used for the production of HRB400 rebar. The size is Φ139mm×6m (outer diameter×length), and the gap between the carbon steel bar 21 and the titanium tube 22 blank is 0.5mm/side.

Material surface treatment: First remove the burrs on the inner surface of the titanium tube blank, then pickle it, and finally clean it with acetone; turn the carbon steel bar at the core to remove the oxide skin on the surface to ensure the steel core The blank is Φ139mm×6m, and then cleaned with acetone.

The carbon steel bar stock is loaded into the titanium tube to form the titanium-steel bimetallic composite billet 200 .

The assembled composite billet 200 is placed in a vacuum chamber and then evacuated to ensure that the vacuum degree is 0.0001Pa; a titanium plate 23 is laid on the end respectively, and then the titanium plate 23 and the titanium tube are welded in a vacuum environment to make the titanium plate 23 There is no gap between the tube 22 and the titanium plate 23, so that the gap between the carbon steel bar 21 and the titanium tube 22 forms a closed vacuum environment.

The composite billet 200 is placed in a heating furnace and heated in a weak oxygen environment, the oxygen volume content of the weak oxidizing atmosphere is ≤5%, the heating time is 4 hours, and the discharge temperature is controlled at 1060°C.

Hot-rolled, rolled into a corrosion-resistant titanium-steel composite steel bar with a diameter of Φ25mm, wherein the thickness of the titanium coating is 0.83mm. Among them, the starting rolling temperature was controlled to 980°C, and the finishing rolling temperature was controlled to 850°C.

Example 2

In this example, composite steel bars of the same type as Example 1 were prepared. The preparation process is basically the same, the differences are:

The composite billet is heated under the protection of inert gas; and the heating temperature is controlled to 980°C.

Example 3

In this example, composite steel bars of the same type as Example 1 were prepared. The preparation process is basically the same, the differences are:

The heating temperature of the composite billet in the heating furnace is controlled to 1100°C.

The corrosion-resistant titanium-steel composite steel bar provided by the utility model has better anti-corrosion performance because the coating material is titanium material; and the anti-oxidation performance of the titanium material is better than that of austenitic stainless steel, and the corrosion resistance in wet chlorine gas is The performance is also far superior to other metals. Therefore, the corrosion-resistant titanium-steel composite steel bar provided by the utility model is of great significance for improving the quality of construction projects and prolonging the service life.

The corrosion-resistant titanium-steel composite steel bar provided by the utility model has better mechanical properties, which can be explained by tensile test and cold bending test. The test results of the mechanical properties of the composite steel bars are as follows:

Mechanical properties test results of composite steel bars

Among them, R _El represents the lower yield strength, R _m represents the tensile strength, and A represents the elongation after fracture.

The corrosion-resistant titanium-steel composite steel bar provided by the utility model has no phenomena such as delamination and poor bonding at the fracture of the tensile test, indicating that the two are metallurgically bonded and have excellent bonding performance.

Each embodiment in this specification is described in a progressive manner, and the same and similar parts between the various embodiments may be referred to each other, and each embodiment focuses on the differences from other embodiments.

The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and alterations made to these embodiments without departing from the principle and spirit of the present invention still fall within the protection scope of the present invention.

Claims (9)

1. A corrosion-resistant titanium-steel composite reinforcing bar is characterized in that, comprising a carbon steel core and a titanium cladding wrapped on the surface of the carbon steel core, and the carbon steel core is metallurgically combined with the titanium cladding ; The titanium coating is prepared and formed by using a pure titanium tube or a titanium alloy tube. 2 . The corrosion-resistant titanium-steel composite bar according to claim 1 , wherein the corrosion-resistant titanium-steel composite bar is a ribbed bar or a smooth round bar. 3 . 3 . The corrosion-resistant titanium-steel composite reinforcing bar according to claim 1 , wherein the carbon steel core is made of low carbon steel or low alloy steel. 4 . 4 . The corrosion-resistant titanium-steel composite rebar according to claim 1 , wherein the thickness of the titanium coating is 0.2-1 mm. 5 . 5. The corrosion-resistant titanium-steel composite reinforcing bar according to any one of claims 1-4, wherein the carbon steel core is made of a carbon steel bar as a raw material, and the titanium coating is made of a titanium tube Raw material, the carbon steel bar and the titanium tube are assembled to form the corrosion-resistant titanium-steel composite steel bar by a hot rolling process. 6 . The corrosion-resistant titanium-steel composite rebar according to claim 5 , wherein the cross-sectional shape of the titanium tube and the carbon steel bar is the same. 7 . 7 . The corrosion-resistant titanium-steel composite rebar according to claim 6 , wherein the cross-sectional shape of the carbon steel bar is square or circular, and the cross-sectional shape of the titanium tube is correspondingly square or circular. 8 . 8 . The corrosion-resistant titanium-steel composite rebar according to claim 7 , wherein the side length or outer diameter of the cross-section of the carbon steel bar is 120-180 mm. 9 . 9 . The corrosion-resistant titanium-steel composite rebar according to claim 8 , wherein the carbon steel bar has a length of 3-12 m. 10 .

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