Special medium-low-steel-grade pipeline steel for hydrogen transmission as well as preparation method and application of special medium-low-steel-grade pipeline steel

Abstract

The invention relates to medium-low steel grade pipeline steel special for hydrogen transmission and a preparation method and application thereof, and relates to the technical field of pipeline steel. The medium and low steel grade pipeline steel special for hydrogen transmission comprises the following chemical components in percentage by mass: 0.030 to 0.050 percent of C, 0.08 to 0.13 percent of Si, 0.70 to 0.90 percent of Mn, 0.025 to 0.040 percent of Nb, 0.010 to 0.020 percent of V, 0.010 to 0.020 percent of Ti, less than or equal to 0.035 percent of Al, less than or equal to 0.001 percent of S, less than or equal to 0.012 percent of P, less than or equal to 0.0050 percent of N, less than or equal to 0.0002 percent of H and less than or equal to 0.0030 percent of O. The medium-and-low-steel-grade pipeline steel special for hydrogen transmission, which is extremely excellent in hydrogen resistance, is obtained and does not need to be subjected to heat treatment.

Description

Technical Field

[0001] The present invention relates to the technical field of pipeline steel, and in particular to medium- and low-grade pipeline steel specially used for hydrogen transportation, and a preparation method and application thereof. Background Art

[0002] With the depletion of traditional resources and the deterioration of climate conditions, it is inevitable for mankind to accelerate the transformation from traditional energy such as fossil fuels to new green energy. Hydrogen energy is a clean secondary energy source that can be used as an efficient energy storage carrier. The development of the hydrogen energy industry is considered to be the only way for my country to achieve the national strategy of carbon peak and carbon neutrality. In order to achieve economical and efficient hydrogen transportation, the use of long-distance pipelines is one of the most suitable methods. However, the higher the hydrogen pressure and the higher the strength of the material, the more obvious the hydrogen embrittlement and hydrogen-induced cracking of the pipeline. New hydrogen pipelines face problems such as poor hydrogen resistance of pipeline steel materials in hydrogen environments, difficult to determine process parameters, and lack of supporting standards. It is urgent to develop special steel for hydrogen transportation to meet the development needs of a hydrogen energy society. In view of this, the present invention provides a medium and low grade hydrogen transportation special pipeline steel and its preparation method and application. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a medium-low steel grade hydrogen transport pipeline steel and its preparation method and application. The purpose is to obtain medium-low steel grade hydrogen transport pipeline steel with extremely excellent hydrogen resistance without heat treatment.

[0004] The technical solution of the present invention to solve the above technical problems is as follows:

[0005] In the first aspect, a medium and low grade steel for hydrogen transmission dedicated pipeline is provided, wherein the medium and low grade steel for hydrogen transmission dedicated pipeline includes the following chemical components calculated by mass percentage: C: 0.030-0.050%, Si: 0.08-0.13%, Mn: 0.70-0.90%, Nb: 0.025-0.040%, V: 0.010-0.020%, Ti: 0.010-0.020%, Al≤0.035%, S≤0.001%, P≤0.012%, N≤0.0050%, H≤0.0002%, and O≤0.0030%.

[0006] Based on the above technical solution, the present invention can also be improved as follows.

[0007] Furthermore, the medium and low steel grade dedicated hydrogen transmission pipeline steel includes at least one of L245 grade dedicated hydrogen transmission hot rolled plate and X52 grade dedicated hydrogen transmission hot rolled plate.

[0008] Furthermore, the L245 grade hot-rolled plate for hydrogen transmission includes the following chemical components in percentage by mass: C: 0.030-0.040%, Si: 0.08-0.13%, Mn: 0.70-0.80%, Nb: 0.025-0.035%, V: 0.010-0.015%, Ti: 0.010-0.015%, Al≤0.035%, S≤0.001%, P≤0.012%, N≤0.0050%, H≤0.0002%, and O≤0.0030%.

[0009] Furthermore, the L245 grade hot-rolled plate for hydrogen transport includes the following chemical components in percentage by mass: C: 0.035%, Si: 0.12%, Mn: 0.75%, Nb: 0.031%, V: 0.015%, Ti: 0.013%, Al≤0.035%, S≤0.001%, P≤0.012%, N≤0.0050%, H≤0.0002%, and O≤0.0030%.

[0010] Furthermore, the X52 grade hot-rolled plate for hydrogen transport includes the following chemical components in percentage by mass: C: 0.040-0.050%, Si: 0.08-0.13%, Mn: 0.80-0.90%, Nb: 0.033-0.040%, V: 0.010-0.020%, Ti: 0.010-0.020%, Al≤0.035%, S≤0.001%, P≤0.012%, N≤0.0050%, H≤0.0002%, and O≤0.0030%.

[0011] Furthermore, the X52 grade hot-rolled plate for hydrogen transport includes the following chemical components in percentage by mass: C: 0.039%, Si: 0.10%, Mn: 0.82%, Nb: 0.035%, V: 0.018%, Ti: 0.020%, Al≤0.035%, S≤0.001%, P≤0.012%, N≤0.0050%, H≤0.0002%, and O≤0.0030%.

[0012] In the second aspect, a method for preparing medium and low steel grade special pipeline steel for hydrogen transmission comprises the following steps: taking pure iron raw material, and sequentially subjecting it to the processes of molten iron desulfurization, converter oxygen blowing decarburization, LF treatment, RH treatment, continuous casting, ingot heating, hot rolling in a rolling mill, and rapid cooling to obtain medium and low steel grade special pipeline steel for hydrogen transmission.

[0013] Furthermore, the heating temperature in the heating of the ingot is 1190-1240°C, and the heating temperature is slightly increased to promote the full dissolution of Nb, V and Ti microalloying elements, and the holding time is 130-160 minutes;

[0014] In the hot rolling mill, the finishing rolling start temperature is 910-950°C, the finishing rolling outlet temperature is 800-840°C, and the curling temperature is 545-585°C; the finishing rolling reduction rate for each pass is greater than 10%, and the cumulative finishing rolling reduction rate is greater than 65%.

[0015] Further, the cooling rate in the rapid cooling is greater than or equal to 15° C. / s.

[0016] In a third aspect, a medium-low steel grade special hydrogen pipeline steel is used to prepare a special hydrogen pipeline.

[0017] The present invention adopts LF treatment for deep deoxidation and desulfurization treatment; RH treatment is mainly for removing impurities such as H and N, and Ca treatment is used for inclusion modification; electromagnetic stirring or dynamic light pressure is used to improve the segregation of continuous casting billet, and the low multiple rating of the casting billet is controlled within C1.0 level. The heating temperature of the heating furnace is 1190-1240°C, and the heating temperature is slightly increased to promote the full dissolution of Nb, V and Ti micro-alloy elements. The holding time of the heating furnace is 130-160min, and the holding time is shortened and the grain boundary dragging effect of the Nb element is combined to refine the reheated austenite grain size; the finishing rolling start temperature is 910-950°C, the finishing rolling outlet temperature is 800-840°C, the curling temperature is 545-585°C, the finishing rolling reduction rate per pass is greater than 10%, and the finishing rolling cumulative reduction rate is greater than 65%; under the condition of certain casting billet composition and segregation, the cooling rate plays an important role in the control of pearlite banding, and the formation of banded structure can be suppressed by accelerating cooling. The present invention studies the changing law of banded structure under different cooling rates and finds that when the cooling rate increases from 2°C / s to 25°C / s, the banded structure is obviously controlled. Therefore, the present invention requires that the cooling rate of accelerated cooling be ≥15°C / s.

[0018] The beneficial effects of the present invention are as follows: the present invention greatly reduces the S, P, C, Mn, Si, Al and other element components that are easily segregated in pipeline steel, and greatly improves the hydrogen embrittlement resistance of pipeline steel products in a high-pressure gaseous hydrogen environment; the strength of the steel is improved by adding Nb, V and Ti microalloying elements, which makes up for the insufficient strength problem caused by reducing the content of elements such as C, Mn, Si and the like; at the same time, the nanophase precipitated by the Nb, V and Ti microalloying elements can be used as a hydrogen trap to greatly improve the hydrogen resistance of the pipeline steel, and the original austenite grain size is refined by controlling the heating temperature and the holding time during the reheating of the ingot, and the organization is refined by a large rolling deformation, a low final rolling temperature and a fast cooling rate to ensure that the grain size is greater than level 11, and the rapid cooling can also reduce the generation of banded organization in the steel, thereby obtaining a medium and low steel grade hydrogen transmission special pipeline steel with extremely excellent hydrogen resistance without the need for heat treatment. DETAILED DESCRIPTION

[0019] The principles and features of the present invention are described below, and the examples are only used to explain the present invention and are not used to limit the scope of the present invention. If no specific technology or conditions are specified in the embodiments, the technology or conditions described in the literature in this field or the product instructions are used. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased through regular channels.

[0020] Example 1 and Comparative Examples 1 and 2:

[0021] Table 1 shows the chemical compositions of Example 1 and Comparative Examples 1 and 2, and Table 2 shows the mechanical and hydrogen resistance properties of Example 1 and Comparative Examples 1 and 2.

[0022] The present embodiment involves a method for preparing L245 grade pipeline steel for hydrogen transmission with medium and low steel grades, comprising the following steps: taking pure iron raw material, and sequentially subjecting it to the processes of molten iron desulfurization, converter oxygen blowing decarburization, LF treatment, RH treatment, continuous casting, billet heating, hot rolling in a rolling mill, and rapid cooling to obtain medium and low steel grade pipeline steel for hydrogen transmission.

[0023] The present embodiment 1 involves a method for preparing a medium- and low-grade hydrogen-transport dedicated pipeline steel. Preferably, the heating temperature in the heating of the ingot is 1190-1240°C, and the heating temperature is slightly increased to promote the full dissolution of Nb, V and Ti microalloying elements, and the holding time is 130-160 min; in the hot rolling of the rolling mill, the finishing rolling start temperature is 910-950°C, the finishing rolling outlet temperature is 800-840°C, and the curling temperature is 545-585°C; the finishing rolling reduction rate per pass is greater than 10%, and the finishing rolling cumulative reduction rate is greater than 65%; the cooling rate in rapid cooling is greater than or equal to 15°C / s.

[0024] The preparation methods involved in Comparative Examples 1 and 2 are the same as those in Example 1.

[0025] Table 1 Chemical compositions of Example 1 and Comparative Examples 1 and 2

[0026]

[0027] Table 2 Mechanical properties and hydrogen resistance of Example 1 and Comparative Examples 1 and 2

[0028]

[0029] As shown in Table 2, the hydrogen resistance results of Comparative Examples 1 and 2 show that the technical route of reducing C and Mn while adding Cu, Cr, and Ni cannot significantly improve the hydrogen resistance of pipeline steel. The hydrogen resistance results of Example 1, Comparative Examples 1, and Comparative Examples 2 show that the present invention greatly reduces the S, P, C, Mn, Si, Al and other element components that are easily segregated in pipeline steel, and improves the strength of steel by adding Nb, V and Ti microalloying elements. Combined with the optimized rolling cooling process, L245-grade hydrogen transmission special pipeline steel with extremely excellent hydrogen resistance can be obtained, and there is no need to add alloying elements such as Cu, Cr, Ni, Mo, and no heat treatment is required, which has an excellent cost performance.

[0030] Example 2 and Comparative Examples 1 and 2:

[0031] Table 3 shows the chemical compositions of Example 2 and Comparative Examples 3 and 4, and Table 4 shows the mechanical and hydrogen resistance properties of Example 2 and Comparative Examples 3 and 4.

[0032] Table 3 Chemical compositions of Example 2 and Comparative Examples 3 and 4

[0033]

[0034] The preparation method of a medium-low steel grade X52 pipeline steel for hydrogen transportation involved in this embodiment 2 is the same as that of embodiment 1. The preparation methods involved in this comparative example 3 and 4 are the same as those of embodiment 1.

[0035] Table 4 Mechanical properties and hydrogen resistance of Example 2 and Comparative Examples 3 and 4

[0036]

[0037] The results of the hydrogen resistance of Comparative Examples 3 and 4 show that the technical route of reducing C and Mn while adding Cu, Cr, and Ni cannot significantly improve the hydrogen resistance of pipeline steel. The results of the hydrogen resistance of Example 2, Comparative Examples 3, and Comparative Examples 4 show that the present invention greatly reduces the S, P, C, Mn, Si, Al and other element components that are easily segregated in pipeline steel, and improves the strength of steel by adding Nb, V, and Ti microalloying elements. Combined with the optimized rolling cooling process, X52-grade hydrogen transmission special pipeline steel with extremely excellent hydrogen resistance can be obtained, and there is no need to add alloying elements such as Cu, Cr, Ni, and Mo, and no heat treatment is required, which has an excellent cost performance.

[0038] In summary, the present invention greatly reduces the S, P, C, Mn, Si, Al and other elemental components that are easily segregated in pipeline steel, and greatly improves the hydrogen embrittlement resistance of pipeline steel products in a high-pressure gaseous hydrogen environment; the strength of the steel is improved by adding Nb, V and Ti microalloying elements, which makes up for the insufficient strength problem caused by reducing the content of elements such as C, Mn, Si and the like; at the same time, the nanophase precipitated by the Nb, V and Ti microalloying elements can be used as a hydrogen trap to greatly improve the hydrogen resistance of the pipeline steel, and the original austenite grain size is refined by controlling the heating temperature and the holding time during the reheating of the ingot, and the organization is refined by a large rolling deformation, a low final rolling temperature and a fast cooling rate to ensure that the grain size is greater than level 11. Rapid cooling can also reduce the formation of banded organization in the steel, thereby obtaining a medium and low steel grade hydrogen transmission special pipeline steel with extremely excellent hydrogen resistance without the need for heat treatment.

[0039] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A medium and low grade steel for hydrogen transport pipeline, characterized in that: The medium and low grade hydrogen transmission dedicated pipeline steel includes the following chemical components calculated by mass percentage: C: 0.030-0.050%, Si: 0.08-0.13%, Mn: 0.70-0.90%, Nb: 0.025-0.040%, V: 0.010-0.020%, Ti: 0.010-0.020%, Al≤0.035%, S≤0.001%, P≤0.012%, N≤0.0050%, H≤0.0002%, O≤0.0030%.

2. According to claim 1, a medium-low steel grade dedicated hydrogen pipeline steel is characterized in that: The medium and low steel grade dedicated hydrogen transmission pipeline steel includes at least one of L245 grade dedicated hydrogen transmission hot rolled plate and X52 grade dedicated hydrogen transmission hot rolled plate.

3. According to claim 2, a medium and low grade steel for hydrogen transport pipeline, characterized in that: The L245 grade hot-rolled plate for hydrogen transmission includes the following chemical components in percentage by mass: C: 0.030-0.040%, Si: 0.08-0.13%, Mn: 0.70-0.80%, Nb: 0.025-0.035%, V: 0.010-0.015%, Ti: 0.010-0.015%, Al≤0.035%, S≤0.001%, P≤0.012%, N≤0.0050%, H≤0.0002%, and O≤0.0030%.

4. According to claim 2, a medium and low grade steel for hydrogen transport pipeline, characterized in that: The L245 grade hot rolled plate for hydrogen transport includes the following chemical components in percentage by mass: C: 0.035%, Si: 0.12%, Mn: 0.75%, Nb: 0.031%, V: 0.015%, Ti: 0.013%, Al≤0.035%, S≤0.001%, P≤0.012%, N≤0.0050%, H≤0.0002%, O≤0.0030%.

5. According to claim 2, a medium and low grade steel for hydrogen transport pipeline, characterized in that: The X52 grade hot rolled plate for hydrogen transport comprises the following chemical components in percentage by mass: C: 0.040-0.050%, Si: 0.08-0.13%, Mn: 0.80-0.90%, Nb: 0.033-0.040%, V: 0.010-0.020%, Ti: 0.010-0.020%, Al≤0.035%, S≤0.001%, P≤0.012%, N≤0.0050%, H≤0.0002%, O≤0.0030%.

6. The medium and low grade hydrogen transport pipeline steel according to claim 2, characterized in that: The X52 grade hot-rolled plate for hydrogen transport includes the following chemical components by mass percentage: C: 0.039%, Si: 0.10%, Mn: 0.82%, Nb: 0.035%, V: 0.018%, Ti: 0.020%, Al≤0.035%, S≤0.001%, P≤0.012%, N≤0.0050%, H≤0.0002%, O≤0.0030%.

7. A method for preparing a medium- and low-grade hydrogen transport pipeline steel according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: taking pure iron raw material, sequentially undergoing the processes of molten iron desulfurization, converter oxygen blowing decarburization, LF treatment, RH treatment, continuous casting, billet heating, hot continuous rolling in a rolling mill, and rapid cooling to obtain medium and low steel grade special pipeline steel for hydrogen transmission.

8. The method for preparing medium and low grade hydrogen transport pipeline steel according to claim 7, characterized in that: The heating temperature in the billet heating is 1190-1240°C, and the holding time is 130-160 minutes; In the hot rolling mill, the finishing rolling start temperature is 910-950°C, the finishing rolling outlet temperature is 800-840°C, and the curling temperature is 545-585°C; the finishing rolling reduction rate for each pass is greater than 10%, and the cumulative finishing rolling reduction rate is greater than 65%.

9. The method for preparing medium and low grade hydrogen transport pipeline steel according to claim 7, characterized in that: The cooling rate in the rapid cooling is greater than or equal to 15° C. / s.

10. Application of medium and low grade hydrogen transport pipeline steel, characterized in that: The medium and low grade hydrogen transport pipeline steel described in any one of claims 1 to 6 is used to prepare hydrogen transport pipelines.

Images