CN114875329B

CN114875329B - Corrosion-resistant and fire-resistant steel with excellent high-temperature creep property under uniaxial tension and production method thereof

Info

Publication number: CN114875329B
Application number: CN202210572091.0A
Authority: CN
Inventors: 童明伟; 卜勇; 易勋; 张开广
Original assignee: Baowu Group Echeng Iron and Steel Co Ltd
Current assignee: Baowu Group Echeng Iron and Steel Co Ltd
Priority date: 2022-05-25
Filing date: 2022-05-25
Publication date: 2022-11-22
Anticipated expiration: 2042-05-25
Also published as: CN114875329A

Abstract

The invention relates to corrosion-resistant and fire-resistant steel with excellent high-temperature creep property under uniaxial tension and a production method thereof, wherein the fire-resistant steel consists of the following elements in percentage by mass: c:0.015 to 0.052%, si:0.05 to 0.15%, mn: 1.60-1.81%, P is less than or equal to 0.002%, S is less than or equal to 0.001%, mo:0.34 to 0.48%, cr:0.27 to 0.43%, cu:0.26 to 0.37%, ni:0.67 to 0.84%, nb: 0.047-0.062%, V: 0.054-0.072%, mg:0.0007 to 0.0017%, hf:0.0005 to 0.0014%, [ O ]: 0.0012-0.0018%, N is less than or equal to 0.0020%, as is less than or equal to 0.001%, sn is less than or equal to 0.001%, and the balance of Fe and inevitable impurities, wherein the chemical components also need to satisfy the following requirements: (Mg +2 Hf)/4, (= O ] =0.45 to 0.58; the production method comprises the following steps: the method has the advantages of simple manufacturing process, short production period, easy large-scale implementation in various metallurgical enterprises, high strength and toughness, high weather resistance, excellent high-temperature creep property and the like.

Description

Corrosion-resistant and fire-resistant steel with excellent high-temperature creep property under uniaxial tension and production method thereof

Technical Field

The invention relates to the technical field of metal material manufacturing, in particular to corrosion-resistant and fire-resistant steel with excellent high-temperature creep property under uniaxial tension and a production method thereof.

Background

In recent years, steel structure engineering in the field of high-rise buildings and the like is more and more emphasized under fire, special performance requirements such as fire resistance, disaster resistance, corrosion resistance and the like are also provided in addition to the conventional performance of steel, so as to reduce casualties and property loss in the case of fire, namely, the steel is required to have excellent high-temperature creep performance and corrosion resistance, not only can be thinned with fireproof coatings and weather-resistant coatings, but also can be improved in resource and energy utilization efficiency, and high-performance structural steel with composite functions of shock resistance, corrosion resistance and fire resistance must be developed.

Before the invention, the invention products disclosed by Chinese invention patent applications 201310160484.1, 201310033300.5, 201110080774.6, 201110247615.0, 200910045146.7, 201110247615.0, 200910011963.0, 200910272414.9, 200910045146.7, 201110080774.6 and 201110247615.0 have good fire resistance but do not have corrosion resistance; in addition, the invention products disclosed in Chinese patent application nos. 201010113848.7, 200910056602.8, 200910180490.7 and 200910056602.8 all have good corrosion resistance, but do not have fire resistance, and the invention products do not have requirements on high-temperature creep property.

The invention of Chinese patent CN1354273A discloses a high performance fire-resistant weather-resistant construction steel and its production method, the product of the invention contains C, si, mn, P, S, cr, mo, ti, als, N, O, cr, ni, cu, ca, B, and one or more of Nb, V, RE, after smelting, rolling and heat treatment, the product has excellent fire-resistant and weather-resistant performance, but the product of the invention needs normalizing and tempering treatment, the strength level is lower, and the high temperature creep performance is not required.

Chinese invention patent CN103695772A discloses fire-resistant weather-resistant earthquake-resistant construction steel with yield strength of 550MPa and a production method thereof, and CN103695773A discloses fire-resistant weather-resistant earthquake-resistant construction steel with yield strength of 690MPa and a production method thereof. However, the two patent applications have the disadvantages that the corrosion resistance is not very ideal, only-20 ℃ impact is required, and the high-temperature creep property is not required.

Chinese invention patent 202010127534.6 discloses a 690MPa grade fire-resistant weather-resistant steel plate for building structures and a manufacturing method thereof, 202010013530.5 discloses a 690MPa grade shock-resistant corrosion-resistant fire-resistant medium plate steel and a manufacturing method thereof, the two invention patents contain C, si, mn, P, S, nb, V, ti, mo, cr, cu, ni and Al, the steel plate has good fire-resistant weather-resistant performance, but the rolled steel plate needs to be tempered in two phase regions, only needs-40 ℃ impact toughness, and does not need high-temperature creep performance.

Chinese patent 202010804777.9 discloses a refractory steel with excellent high temperature creep rupture performance at 700 ℃ for welding structure and a production method thereof, and the product of the invention has the characteristics of excellent refractory performance, high temperature creep performance, welding performance and the like, but the product of the invention does not have corrosion resistance and has lower strength level. In addition, chinese patent invention 202110945932.3 discloses a high-performance corrosion-resistant refractory steel with excellent low-temperature toughness at minus 80 ℃ and a production method thereof, and the product of the invention has high strength, excellent low-temperature toughness, fire-resistant weather-resistant performance, good welding performance and cold processing performance, but contains more noble alloys such as Mo, cr, ni and the like, is difficult to implement in large scale, and does not have requirements on high-temperature creep property.

Disclosure of Invention

The invention provides corrosion-resistant and fire-resistant steel with excellent high-temperature creep property under uniaxial tension and a production method thereof, aiming at overcoming the defects existing in the technical field at present. The invention has simple manufacturing procedure and short production period, can be implemented in large scale in various metallurgical enterprises, and the finished steel plate has the characteristics of high strength and toughness, high weather resistance, excellent high-temperature creep property and the like.

The invention relates to a corrosion-resistant and fire-resistant steel with excellent high-temperature creep property under uniaxial tension, which comprises the following elements in percentage by mass: c:0.015 to 0.052%, si:0.05 to 0.15%, mn: 1.60-1.81%, P is less than or equal to 0.002%, S is less than or equal to 0.001%, mo:0.34 to 0.48%, cr:0.27 to 0.43%, cu:0.26 to 0.37%, ni:0.67 to 0.84%, nb: 0.047-0.062%, V: 0.054-0.072%, mg:0.0007 to 0.0017%, hf:0.0005 to 0.0014%, [ O ]: 0.0012-0.0018%, N is less than or equal to 0.0020%, as is less than or equal to 0.001%, sn is less than or equal to 0.001%, and the balance of Fe and unavoidable impurities, wherein the chemical components also have the following chemical composition: (Mg +2 Hf)/4 [ O ] =0.45 to 0.58.

Preferably, in the refractory steel of the present invention, V: 0.057-0.070%, hf:0.0007 to 0.0013 percent of Al, less than or equal to 0.0007 percent of As and less than or equal to 0.0007 percent of Sn.

The microstructure of the finished refractory steel mainly comprises lath bainite, and a small amount of granular bainite-quasi-polygonal ferrite-M/A islands are used as auxiliary materials, wherein the width of the lath bainite is less than or equal to 1 mu M, and the width of the M/A islands is less than or equal to 0.5 mu M.

The finished refractory steel ReL = 742-770MPa, rm = 887-912 MPa, and KV at-80 DEG C ₂ = 300-333J, and the high-temperature creep rupture time at 700 ℃ is 6.23-6.58 h.

The invention relates to a production method of corrosion-resistant and fire-resistant steel with excellent high-temperature creep property under uniaxial tension, which comprises the following steps:

(1) Smelting in a converter: smelting by adopting an ultra-low phosphorus double-slag method, wherein the dephosphorization rate is more than or equal to 92 percent, and the end point P is less than or equal to 0.001 percent;

(2) Refining outside the furnace: LHF is circularly heated for 6min and desulfurized for 6min, and the end point S is controlled to be less than or equal to 0.001 percent; RH added Mg and Hf and controlled Mg:0.0007 to 0.0017%, hf:0.0005 to 0.0014 percent;

(3) Heating a casting blank: the heating temperature is 1260 to 1280 ℃, the heating rate is 7 to 10min/cm, the heat preservation temperature is 1230 to 1240 ℃, and the heat preservation time is 50 to 60min;

(4) Rolling: the initial rolling temperature of rough rolling in the stage I is 1100-1120 ℃, the final rolling temperature is 1050-1070 ℃, and the single-pass reduction is 32-40 mm; the initial rolling temperature of the finish rolling in the stage II is less than or equal to 980 ℃, the final rolling temperature is (880-4/5 h) DEG C, wherein h is the thickness value of the finished product in mm;

(5) And (3) cooling: the laminar cooling start cooling temperature is 800-820 ℃, and the re-reddening temperature is 280-400 ℃;

(6) And (3) heat treatment: tempering the steel plate at 350-400 deg.c for (h + 50) min when the steel plate thickness is less than or equal to 50 mm; when the thickness of the steel plate is more than 50mm, the furnace time is [ (2.2-2.3) h ] min, and then the steel plate is cooled to room temperature by air, wherein h is the thickness value of the finished product in mm.

The reasons for the limited amounts of the chemical components in the present invention are detailed below:

the content of C is selected to be 0.015-0.052%, C has strong interstitial solid solution strengthening effect, and forms fine carbonitride particles with Nb and V to refine grains and precipitate, so that the strength and the low-temperature toughness are improved. C can also form high-melting-point high-corrosion-resistance Mo and Cr carbides during tempering, and the corrosion resistance, the fire resistance and the high-temperature creep property are improved. When the C content is less than 0.015%, the above effect is limited. When the C content is more than 0.052%, the low-temperature toughness is not favored, so that the C content is limited to 0.015 to 0.052%.

The Si content of the invention is selected to be 0.05-0.15%, the Si has the functions of solid solution strengthening and deoxidation, but is not beneficial to low-temperature toughness and ductility, and in addition, the Mg and the Hf of the invention play the role of a deoxidizer, so the product performance is comprehensively considered, and the Si content is limited to be 0.05-0.15%.

The Mn content of the invention is selected to be 1.60-1.81%, and a proper amount of Mn has the function of refining crystal grains and is an important element for ensuring the strength and the low-temperature toughness of steel. When the Mn content is less than 1.60%, the above-mentioned effect is not significant. When the Mn content is more than 1.81%, weldability is deteriorated and weld crack sensitivity is improved. Therefore, the Mn content is limited to 1.60 to 1.81%.

P is less than or equal to 0.002 percent and S is less than or equal to 0.001 percent, and P and S generally belong to harmful elements but are easy to deviate grain boundaries, so that the brittleness of the grain boundaries is improved, and the low-temperature toughness and the high-temperature creep property are not facilitated. In addition, S is easy to form MnS composite inclusions, and the performance of steel is damaged. Therefore, the P and S contents in the steel should be reduced as much as possible.

The Mo content of the invention is selected to be 0.34-0.48%, most of Mo is dissolved in the matrix in a solid solution manner, and the room temperature strength and the high temperature performance are improved in a solid solution strengthening manner. Mo promotes the formation of high-density dislocation bainite, promotes NbC particles to be uniformly separated out, prevents the NbC particles from being aggregated and grown at high temperature, can also form high-melting-point high-corrosion-resistant Mo carbide during tempering, and improves the corrosion resistance, the fire resistance and the high-temperature creep property. When the Mo content is less than 0.34%, the above effect is limited. When the Mo content is more than 0.48%, the low-temperature toughness and the welding performance are reduced, the alloy cost is increased, and the implementation is not facilitated. Therefore, the Mo content is limited to 0.34-0.48%.

The Cr content of the invention is 0.27-0.43%, and most of Cr is dissolved in the matrix like Mo, so that the room temperature strength and the high temperature creep property are improved in a solid solution strengthening mode. Cr can form a compact oxidation protection film, and the corrosion resistance and the heat resistance are improved. Cr can also form high-melting-point high-corrosion-resistance Cr carbide during tempering, and the corrosion resistance, the fire resistance and the high-temperature creep property are improved. However, too high Cr increases the ductile-brittle transition temperature, which is not favorable for low-temperature toughness and weldability. Therefore, the Cr content is limited to 0.27 to 0.43%.

The Cu selection of the invention is 0.26-0.37%: cu improves strength and corrosion resistance, and epsilon-Cu is precipitated in the tempering process to improve strength. But too high Cu decreases toughness and weldability. Therefore, the Cu content is limited to 0.26 to 0.37%.

The Ni is selected to be 0.67-0.84%, and a proper amount of Ni can ensure low-temperature toughness and corrosion resistance. When the alloy is compounded and added with proper amount of Cr and Cu, the low-temperature toughness and corrosion resistance can be obviously improved. However, since Ni is a precious alloy and tends to form a large amount of scale which is not easily removed when excessive, thereby deteriorating the surface quality, the Ni content is limited to 0.67 to 0.84%.

The content of Nb is selected to be 0.047-0.062%, and a proper amount of Nb can form fine carbonitride particles with C and N to prevent austenite grains from growing to refine the grains, thereby playing the roles of fine grain strengthening and precipitation strengthening and improving the strength and the low-temperature toughness. Particularly, when Mo is added simultaneously, the Mo promotes the NbC particles to be uniformly separated out, prevents the NbC particles from being aggregated and grown at high temperature, and improves the high-temperature creep property. Nb can also increase the recrystallization temperature, and is beneficial to high-temperature rolling. When the Nb content is less than 0.047%, the above-mentioned effect is limited, and when the Nb content is more than 0.062%, nb carbonitrides rather tend to aggregate and grow, adversely affecting the product of the present invention. Therefore, the Nb content is limited to 0.047-0.062%.

The V of the invention is selected to be 0.054-0.072%, most of the V is dissolved in a matrix and can form fine carbonitride particles with C and N to prevent austenite grains from growing so as to refine the grains, thus playing the roles of fine grain strengthening and precipitation strengthening, improving the strength and the low-temperature toughness, and the V carbonitride particles have better stability at high temperature, preventing grain boundary slippage at high temperature, delaying crack propagation and improving the high-temperature creep property. However, when the V content is less than 0.054%, the above effect is limited, and when the V content is more than 0.072%, the amount of V dissolved in the matrix is large, which is not favorable for low-temperature toughness. Therefore, V is limited to 0.054 to 0.072%, preferably 0.057 to 0.070%.

The Mg of the invention is selected to be 0.0007-0.0017%, the Mg is an important element for ensuring the performance of the product, not only can spheroidize the deteriorated sulfide inclusions and purify the steel, but also can take the nanoscale MgO mass point as an AF nucleation core to promote the formation of AF, refine the effective grain size of AF and improve the low-temperature toughness and HAZ toughness of the steel. When the Mg content is less than 0.0007%, the above effects are limited, and when the Mg content is more than 0.0017%, large-size composite inclusions are easily formed, the steel purity is reduced, and the low-temperature toughness is not facilitated. Therefore, mg is limited to 0.0007 to 0.0017%.

The content of Hf is selected to be 0.0005-0.0014%, and Hf is also an important element for ensuring the performance of the product and has high temperature resistance and corrosion resistance. A proper amount of Hf can form HfO2 oxide particles with high melting point and high corrosion resistance with O, and the HfO2 oxide particles can effectively inhibit the sliding of crystal boundary at high temperature, delay the crack expansion and fracture and improve the high-temperature creep property and the corrosion resistance. When the Hf content is less than 0.0005%, the above-mentioned effect is limited, and when the Hf content is more than 0.0014%, large-sized inclusions containing Hf oxides are easily formed, reducing the purity of the steel, and impairing the low-temperature toughness and corrosion resistance. Therefore, hf is limited to 0.0005 to 0.0014%, preferably 0.0007 to 0.0013%.

The content of O is 0.0012-0.0018%, O is harmful gas, but in order to obtain the product performance of the invention, the functions of Mg and Hf in steel must be fully exerted, and especially sufficient MgO and HfO2 oxide particles are formed, so that the product performance of the invention can be obtained. Therefore, O is limited to 0.0012 to 0.0018%.

The content of N is less than or equal to 0.0020%, and in order to prevent the increase of solid solution N in steel and increase the risk of strain aging sensitivity, the content of N is limited to less than or equal to 0.0020%.

As is less than or equal to 0.001 percent, sn is less than or equal to 0.001 percent, as and Sn are easy to deviate from grain boundaries, the brittleness of the grain boundaries is increased, the strength and the low-temperature toughness of the grain boundaries are reduced, and the high-temperature creep performance is not facilitated, so the content of As is less than or equal to 0.001 percent, sn is less than or equal to 0.0007 percent, preferably less than or equal to 0.0007 percent.

Meanwhile, the chemical components also have to meet the following requirements: (Mg +2 Hf)/4 [ O ], [ 2]And = 0.45-0.58. When (Mg +2 Hf)/4 [ 2 ] O]MgO and HfO formed at < 0.45 ₂ The product performance of the invention can not be obtained due to insufficient mass point quantity of the oxide. When (Mg +2 Hf)/4 [ 2 ] O]If the content is more than 0.58, large-size inclusions are easily formed, the purity of steel is reduced, and the low-temperature toughness and the corrosion resistance are not facilitated.

The steel of the invention contains the chemical components, and the balance of Fe and inevitable impurities.

The invention aims to provide the corrosion-resistant and fire-resistant steel with excellent high-temperature creep property under uniaxial tension and the production method thereof, the related steel plate finished product has the characteristics of simple manufacturing process, short production period, easy large-scale implementation in various metallurgical enterprises, high strength and toughness, high weather resistance, excellent high-temperature creep property and the like.

The production method of the steel plate is characterized by accurately controlling the technological parameters, and comprises the following specific measures:

(1) Smelting in a converter: the smelting is carried out by adopting an ultra-low phosphorus double-slag method, the dephosphorization rate is more than or equal to 92 percent, the end point P is less than or equal to 0.001 percent, so that the content of P is reduced as much as possible, the P is prevented from deviating to a crystal boundary, the brittleness of the crystal boundary is improved, and the low-temperature toughness and the high-temperature creep property are reduced.

(2) Refining outside the furnace: LHF is heated for 6min and desulfurized for 6min circularly, rapid deep desulfurization reaction is promoted, the end point S is controlled to be less than or equal to 0.001%, grain boundary segregation is prevented, grain boundary brittleness is improved, and low-temperature toughness and high-temperature creep property are reduced; RH added Mg and Hf and controlled Mg:0.0007 to 0.0017%, hf:0.0005 to 0.0014%, preferably Hf:0.0007 to 0.0013 percent so as to form enough HfO2 oxide particles with high melting point and high corrosion resistance and ensure the high-temperature creep property and the corrosion resistance.

(3) Heating a casting blank: in order to ensure that Mo, cr and Cu in steel are dissolved in austenite and ensure sufficient austenitization, reduce the degree of center segregation and prevent austenite grains from excessively growing, the heating temperature, the heat preservation temperature and the heat preservation time of a casting blank are limited.

(4) Rolling and cooling: heating a casting blank out of a furnace, removing phosphorus under high pressure, and carrying out I-stage rough rolling when the temperature of the casting blank is 1100-1120 ℃, wherein the single-stage reduction is controlled to be 32-40 mm, so that multi-stage large-reduction rolling is carried out in an austenite complete recrystallization region, columnar crystal grains are fully crushed after multi-stage rolling, the rolling clearance time is shortened, the austenite crystal grains are prevented from growing large, and the I-stage final rolling temperature is controlled to be 1050-1070 ℃ so as to further refine the crystal grains; the initial rolling temperature of the finish rolling in the stage II is controlled to be less than or equal to 980 ℃, the aim is to roll in the austenite non-recrystallization region in the stage II so as to avoid mixed crystal tissues, the grains can be further refined by rolling and finish rolling at lower temperature, the comprehensive performance is improved, the initial cooling temperature of laminar cooling is controlled to be 800-820 ℃, and the temperature of re-reddening is controlled to be 280-400 ℃, so that the required tissue structure of the invention can be obtained, and the required mechanical property level of the invention can be obtained.

(5) The steel plate is tempered at 350-400 ℃ and kept in a furnace for a certain time, so that residual stress is eliminated as far as possible, and carbides of Mo and Cr are fully precipitated to obtain the mechanical property level required by the invention.

The finished steel plate microstructure mainly comprises lath bainite, and a small amount of granular bainite-quasi-polygonal ferrite-M/A island, wherein the width of the lath bainite is less than or equal to 1 mu M, the width of the M/A island is less than or equal to 0.5 mu M, reL = 742-770MPa, rm = 887-912 MPa, and KV at-80 DEG C ₂ And (4) the creep rupture time at 700 ℃ is 6.23-6.58 h.

Compared with the prior art, the method has the advantages of simple manufacturing process, short production period and easy large-scale implementation in various metallurgical enterprises, and the finished steel plate produced by the method has the characteristics of high strength and toughness, high weather resistance, excellent high-temperature creep property and the like.

Drawings

FIG. 1 is a photograph of a microstructure of a finished steel plate, enlarged to 20 μm, according to example 5 of the present invention;

FIG. 2 is a photograph of a microstructure of a finished steel sheet obtained in example 5 of the present invention enlarged to 1 μm.

Detailed Description

In order to better explain the technical solution of the present invention, the technical solution of the present invention is further described below with reference to specific examples, which are only exemplary to illustrate the technical solution of the present invention and do not limit the present invention in any way.

Table 1 below is a table showing values of chemical components (wt%) of the steel sheets according to the examples of the present invention;

the following table 2 is a list of values of main process parameters of the steel plates according to the embodiments of the invention;

the following table 3 is a list of mechanical property test results of the steel plates according to the embodiments of the invention;

wherein the thicknesses of the products of examples 1 to 8 were 15mm, 20mm, 30mm, 40mm, 50mm, 60mm, 70mm and 80mm, respectively.

The production method of the corrosion-resistant and fire-resistant steel with excellent high-temperature creep property under uniaxial tension comprises the following steps:

(5) And (3) cooling: the laminar cooling temperature is 800-820 ℃, and the temperature of red return is 280-400 ℃;

TABLE 1 tabulation of chemical composition (wt%) values for steel sheets of examples of the present invention

Table 2 list of values of process parameters of steel plates according to various embodiments of the present invention

Table 3 list of mechanical property test results of steel plates according to the embodiments of the present invention

( Note: the high-temperature creep property under uniaxial tension is evaluated through the high-temperature creep rupture time, the execution standard is GB/T2039, the test temperature is 700 ℃, and the test load is 2/3 of the normal-temperature yield strength ReL of the material; the corrosion resistance is evaluated by the corrosion weight loss rate after 225h of periodic infiltration corrosion test, and the execution standard is TB/T2375 )

Samples were taken from the steel sheets 1/4 of the thickness of the steel sheets of the examples and comparative examples of the present invention to conduct tests of ordinary temperature tensile properties, longitudinal impact work at-80 ℃ and high temperature (700 ℃) creep properties under uniaxial tension. Test results show that the finished steel plate produced by the method of the invention has ReL = 742-770MPa, rm = 887-912MPa, A = 30.7-35.0%, and KV at-80 DEG C ₂ = 300-333J, the high-temperature creep rupture time at 700 ℃ is 6.23-6.58 h, and the corrosion weight loss rate is 0.2631-0.2710 g/m ² H, high toughness, high weather resistance, excellent high temperature creep property and the like.

FIGS. 1 and 2 are photographs showing the microstructure of a finished steel plate obtained in example 5 of the present invention, and it can be seen from the photographs that the microstructure of the steel of the present invention is characterized by mainly lath bainite, supplemented by a small amount of granular bainite, quasi-polygonal ferrite, and M/A islands, wherein the width of lath bainite is not more than 1 μ M, and the width of M/A islands is not more than 0.5 μ M, and it is this uniform and fine multi-phase structure that ensures the high strength, high plasticity and excellent low temperature toughness of the present invention.

The embodiments described above are merely specific examples of the present invention exemplified for explaining the present invention, and do not limit the present invention in any way, and any insubstantial changes from the above-described contents and forms without departing from the scope of the present invention are considered to fall within the scope of the present invention as claimed.

Claims

1. The corrosion-resistant and fire-resistant steel with excellent high-temperature creep property under uniaxial tension is characterized by comprising the following elements in percentage by mass: c:0.015 to 0.052%, si:0.05 to 0.15%, mn: 1.60-1.81%, P is less than or equal to 0.002%, S is less than or equal to 0.001%, mo:0.34 to 0.48%, cr:0.27 to 0.43%, cu:0.26 to 0.37%, ni:0.67 to 0.84%, nb: 0.047-0.062%, V: 0.054-0.072%, mg:0.0007 to 0.0017%, hf: 0.0005-0.0014%, [ O ]]：0.0012～0.0018%，[N]Less than or equal to 0.0020 percent, less than or equal to 0.001 percent of As, less than or equal to 0.001 percent of Sn, and the balance of Fe and inevitable impurities, and simultaneously the chemical components also have the following requirements: (Mg +2 Hf)/4 [ O ], [ 2]= 0.45-0.58; the microstructure of the prepared finished refractory steel takes lath bainite as a main component and a small amount of granular bainite-quasi-polygonal ferrite-M/A islands as auxiliary components, wherein the width of the lath bainite is less than or equal to 1 mu M, and the width of the M/A islands is less than or equal to 0.5 mu M; the prepared finished refractory steel ReL = 742-770MPa, rm = 887-912 MPa, and KV at-80 DEG C ₂ = 300-333J, and the high-temperature creep rupture time at 700 ℃ is 6.23-6.58 h;

the production method of the refractory steel comprises the following steps:

(1) Smelting in a converter: smelting by an ultra-low phosphorus double-slag method, wherein the dephosphorization rate is more than or equal to 92 percent, and the end point P is less than or equal to 0.001 percent;

2. The corrosion-resistant and fire-resistant steel excellent in high-temperature creep property under uniaxial tension according to claim 1, wherein: v: 0.057-0.070%, hf:0.0007 to 0.0013 percent of Al, less than or equal to 0.0007 percent of As and less than or equal to 0.0007 percent of Sn.