CN110396643A - 700MPa grades of hot rolling high-strength quake-proof reinforcing steel bars of a kind of inexpensive hot rolling and preparation method thereof - Google Patents

700MPa grades of hot rolling high-strength quake-proof reinforcing steel bars of a kind of inexpensive hot rolling and preparation method thereof Download PDF

Info

Publication number
CN110396643A
CN110396643A CN201910804154.9A CN201910804154A CN110396643A CN 110396643 A CN110396643 A CN 110396643A CN 201910804154 A CN201910804154 A CN 201910804154A CN 110396643 A CN110396643 A CN 110396643A
Authority
CN
China
Prior art keywords
rolling
hot rolling
reinforcing bar
slab
temperature
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN201910804154.9A
Other languages
Chinese (zh)
Inventor
白瑞国
张春雷
褚文龙
王宝华
张俊粉
单红超
贾元海
王林
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
HBIS Co Ltd Chengde Branch
Original Assignee
HBIS Co Ltd Chengde Branch
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by HBIS Co Ltd Chengde Branch filed Critical HBIS Co Ltd Chengde Branch
Priority to CN201910804154.9A priority Critical patent/CN110396643A/en
Publication of CN110396643A publication Critical patent/CN110396643A/en
Pending legal-status Critical Current

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/06Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires
    • C21D8/065Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires of ferrous alloys
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/06Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires
    • C21D8/08Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires for concrete reinforcement
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C33/00Making ferrous alloys
    • C22C33/04Making ferrous alloys by melting
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/001Ferrous alloys, e.g. steel alloys containing N
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/02Ferrous alloys, e.g. steel alloys containing silicon
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/04Ferrous alloys, e.g. steel alloys containing manganese
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/12Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00Microstructure comprising significant phases
    • C21D2211/005Ferrite
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00Microstructure comprising significant phases
    • C21D2211/009Pearlite

Abstract

The present invention relates to 700MPa grades of hot rolling high-strength quake-proof reinforcing steel bars of a kind of inexpensive hot rolling and preparation method thereof, based on mass percentage, it is composed of the following components: C 0.30-0.35%, V 0.14-0.20%, Si 0.40-0.80%, Mn 1.20-1.60%, N 200-400ppm, surplus are Fe and inevitable impurity.The present invention makes full use of the synergistic effect of each element by compound addition V-N steel, in conjunction with the control of each process temperature in the operation of rolling, has obtained the reinforcing bar product that tissue is pearlite+ferrite and grain size >=10 grade.Gained reinforcing bar has a good application prospect with excellent mechanical property, yield strength >=700MPa, tensile strength >=850MPa, elongation after fracture A >=14.0%, strong flexor ratio >=1.25, maximum, force percentage of total elongation Agt >=9.0%.

Description

700MPa grades of hot rolling high-strength quake-proof reinforcing steel bars of a kind of inexpensive hot rolling and preparation method thereof
Technical field
The invention belongs to Ferrous Metallurgys and technical field of steel rolling, are related to a kind of hot rolling 700MPa grades of hot rolling high-strength quake-proof reinforcing steel bars And preparation method thereof more particularly to a kind of inexpensive 700MPa grades of hot rolling high-strength quake-proof reinforcing steel bars of hot rolling and preparation method thereof.
Background technique
With the rapid development of building industry, the engineering structures such as Municipal engineering and skyscraper want reinforcement property Ask higher and higher, the safety of building structure, shock resistance problem cause common concern, and improve building safety and shock resistance Key be improve reinforcing bar intensity and comprehensive performance.In the case where country advocates energy-saving and emission-reduction, environmentally protective background energetically, as The construction industry of resource consumption rich and influential family, regular tenacity reinforcing bar have been unable to satisfy the need of development as the situation of construction(al)steel main material Want, thus development of high strength, high performance steel have become there is an urgent need to.
Reinforcing bar is currently the maximum rolling shapes of China's volume of production and marketing, and the quality level of reinforcing bar is first intake already close to international It is flat, but there are also a certain distance for use intensity and developed country.China's hot rolled ribbed bars are divided into 400,500 and by strength grade 600 3 kinds of intensity ranks.It is commonly used in the major projects such as nuclear power, landmark by the popularization and application of many years HRB500(E).With the implementation that issues of GB 1499.2-2018, national standard reinforcing bar interior tissue is proposed in new standard higher It is required that and preventing to wear the techniques such as water production national standard reinforcing bar product.
Reinforcing bar grade used by external concrete structure is substantially with 400MPa grades, 500MPa grades, 600MPa grade three 400MPa grades and the above high tensile reinforcement are generallyd use based on grade, in engineering, some developed countries (such as Britain, Germany) have used 600MPa grades of reinforcing bars.Developed countries obviously surmount China in high tensile reinforcement research and development and application aspect, and reinforcing bar application is universal 1-2 grade higher than China, and corresponding rebar standards are also being constantly updated, reinforcing bar rank highest have reached 700Mpa grades with On.As Korea Spro marks the GR100 of SD700 and SD600S in (KS D3504:2016), American Standard (ASTM A615-A615M-2015ae1) Deng so high tensile reinforcement will will gradually become the development trend of building bar.
Currently, the production of domestic hot-rolled reinforced bar needs to control carbon content no more than 0.28%, while to the limit of carbon steel equivalent System is more stringent, therefore can only improve alloy addition level largely to realize the raising of reinforced steel bar strength, and which results in reinforcing bar productions The raising of cost makes the building bar of higher level be difficult to promote and apply.It is high that the present invention provides a kind of carbon contents, and tension The outstanding hot-rolled reinforced bar and preparation method thereof of intensity, elongation after fracture, the production cost of gained hot-rolled reinforced bar is low, can satisfy urgency Increase severely the long market demand and higher and higher industry requirement.
Summary of the invention
In view of problems of the prior art, the purpose of the present invention is to provide a kind of hot rolling 700MPa grades of hot rollings are high-strength Anti-seismic steel bar and preparation method thereof more particularly to a kind of inexpensive 700MPa grades of hot rolling high-strength quake-proof reinforcing steel bars of hot rolling and its preparation side Method makes gained reinforcing bar interior tissue ferrite and pearl by improving the composition of carbon content and trace alloying element in reinforcing bar Body of light, stable mechanical property meet big batch steady production demand.
To achieve this purpose, the present invention adopts the following technical scheme:
In a first aspect, the present invention provides a kind of 700MPa grades of hot rolling high-strength quake-proof reinforcing steel bars of inexpensive hot rolling, by quality hundred Divide content meter, the reinforcing bar is composed of the following components: C 0.30-0.35%, V 0.14-0.20%, Si0.40-0.80%, Mn 1.20-1.60%, N 200-400ppm, surplus are Fe and inevitable impurity.
Hot-rolled reinforced bar production technology is different from producing process of sheet and strip, and almost ausrolling, especially small dimension fine grain is strong Change effect is unobvious, therefore is difficult to for reinforced steel bar strength to be increased to 700MPa or more rank using the V-N steel of single-element. The present invention selects the mode of compound addition V-N steel to improve, and obtains a large amount of deformation bands and position in roughing and finish rolling stage Wrong band, and there is part precipitate (VC, VN etc.) to be precipitated along crystal boundary, Zona transformans and dislocation, these precipitate pinning crystal boundaries, resistance The only roughening of austenite grain ultimately forms pearlite+iron element so that phase transformation generates fine and closely woven ferrite in cooling procedure The reinforcing bar tissue of body organizes grain size >=10 grade.
" low cost " of the present invention refers to, the present invention is passed through by the content of two kinds of C, N cheap elements in raising reinforcing bar V, the cooperation of the elements such as the synergistic effect of the elements such as C, N and Mn, Si, makes reinforcing bar on the basis of reducing production cost, can Meet 700MPa grades of the needs of.
V is a kind of important V-N steel element, and Austenite Grain Refinement effect is weaker.V element energy in the present invention It is enough that nanoscale V (C, N) compound is precipitated during the rolling process, increase ferrite nucleation point, prevents ferrite crystal grain from growing up, have Extremely strong precipitation precipitation enhancement, can significantly improve the yield strength of reinforcing bar.
The content of V is 0.14-0.20% in reinforcing bar of the present invention, for example, can be 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19% or 0.20% etc..Meeting higher cost when V content is excessively high, meeting can not be with C, N when V content is too low Enough V (C, N) compound is formed, the intensity of steel matrix is unable to satisfy 700MPa grades of reinforcing bar requirements.
C is a kind of effective intensified element, and C can be dissolved the yield strength for improving hot-rolled reinforced bar in the base and tension is strong Degree, and C's is cheap, in the operation of rolling, C element can form nanoscale V (C, N) compound with V, N, and it is strong to form precipitating Change, improves the intensity of steel matrix.
The content of C element is 0.30-0.35% in reinforcing bar of the present invention, for example, can be 0.30%, 0.31%, 0.32%, 0.33%, 0.34% or 0.35% etc..When C content is lower, C and V, N can not form enough V (C, N) chemical combination Object, the intensity of steel matrix are unable to satisfy 700MPa grades of reinforcing bar requirements;When C content is excessively high, the presence of C can reduce the modeling of reinforcing bar Property and toughness, while reducing its welding performance;Therefore, it is 0.30- that the present invention, which needs to control the content of C element in reinforcing bar, 0.35%.
The presence of N element can promote the precipitation of V in reinforcing bar of the present invention, refine the precipitation size of V (C, N) compound, The potentiality that compound precipitation strength can be given full play to raising screw thread hardness of steel, and reduce the usage amount of alloy, reduce production cost With obvious effect.
In heretofore described reinforcing bar the content of N element be 200-400ppm, such as can be 200ppm, 250ppm, 300ppm, 350ppm or 400ppm can not form the V (C, N) met the requirements when the content of N element is too low, in the reinforcing bar Compound, the intensity of steel matrix are unable to satisfy 700MPa grades of reinforcing bar requirements;When the too high levels of N element, N element can make steel The timeliness of muscle is deteriorated;Therefore, it is 200-400% that the present invention, which needs to control the content of N element in reinforcing bar,.
Silicon is reducing agent and deoxidier common in steel, can significantly improve the elastic limit, yield point and tensile strength of steel, Mainly play solution strengthening by being solid-solubilized in ferrite, and can reduce the diffusion speed of carbon in austenite Degree postpones ferrite and pearlite phase transformation, yield strength and tensile strength can be improved, but element silicon can improve ductile-brittle transiton temperature Degree, therefore its content is unsuitable excessively high.
The zone of reasonableness of silicone content is 0.40-0.80% in the present invention, for example, can be 0.40%, 0.45%, 0.50%, 0.55%, 0.60%, 0.65%, 0.70%, 0.75% or 0.80% etc..
Manganese is main solution strengthening element, and improves the effective element of the harden ability of steel.Manganese is as one in the present invention The main solution strengthening element of kind improves the intensity of matrix, and excessively high manganese content can reduce ferrite and generate temperature, makes precipitated phase too It crosses tiny and influences strengthening effect, meanwhile, manganese content is higher equally to improve carbon equivalent, influence welding performance.
Manganese content zone of reasonableness is 1.20-1.60% in the present invention, for example, can be 1.20%, 1.25%, 1.30%, 1.35%, 1.40%, 1.45%, 1.50%, 1.55% or 1.60% etc..
The present invention improves strong flexor ratio index by the way of improving carbon, but as the raising of carbon content will lead to toughness Reduction, therefore the content of impurity element is no more than 350ppm, the toughness index of reinforcing bar can otherwise reduced lower, it is difficult to reach To requirement, while the raising of element sulphur will also improve the quantity of MnS field trash, and the comprehensive performance of reinforcing bar is made to be deteriorated.
P and s, which are two kinds, common are harmful element, and phosphorus can increase the cold brittleness of steel, welding performance is made to degenerate, and reduce modeling Property, so that cold-bending property is degenerated.Sulphur can make steel generate red brittleness, reduce the ductility and toughness of steel, cause in forging and rolling Crackle, it is also unfavorable to welding performance, reduce corrosion resistance.Therefore the present invention in p and s zone of reasonableness≤0.035%.
Second aspect, the present invention provides a kind of preparation method of reinforcing bar as described in relation to the first aspect, the method includes The process that next coming in order carry out: converter smelting, LF refining, continuous casting, slab cooling, slab heating, rolling, cold bed are cooling.
For the present invention, based on components described above scheme, slab is obtained by converter smelting, LF refining, continuous casting Process use this field conventional technology, the present invention do not do particular determination to it.Illustratively, above-mentioned to smelt Process to slab can use following scheme, but non-be only limitted to this:
After oxygen coverter is added in molten iron or half steel, steel scrap, top bottom blowing is carried out, lime, dolomite, slugging is added Ball carries out slag making;Control aim carbon >=0.06wt%, 1650~1680 DEG C of tapping temperature;Using wash heat and whole bottom blowing when tapping Argon, when molten steel goes out to more than when 1/4, deoxidier, silicomangan, ferrosilicon, ferrovanadium nitride etc., in ladle molten steel are added into ladle It is added when out to 3/4, to carry out deoxidation alloying.Molten steel send LF furnace to be refined after tapping, pre- Argon 3 minutes, then Electrode slugging is carried out, lime is added, control basicity of slag is 5.0-8.0, and alloy fine tuning ingredient is added after slag making and reaches target Control composition;To molten steel Argon 8 minutes;After heating molten steel to temperature is 1570-1590 DEG C, conventional coverture is added, send continuous casting Process, tundish temperature are 1520-1540 DEG C, are casting continuously to form small billet.
After obtaining the slab that ingredient determines, the cooling process conditions pair of subsequent slab cooling, slab heating, rolling, cold bed The performance of gained reinforcing bar of the invention has large effect.
Wherein, in slab cooling process, the present invention selects to carry out slab into slow cooling processing, and the time of slow cooling >=for 24 hours.This Invention makes time of slow cooling >=be because VN, can be in phase transition process due to the different solubility in its γ phase and α phase in steel for 24 hours It is precipitated along austenite grain boundary, to destroy the ductility of steel, makes steel that there is crack sensitivity, crack during the rolling process, with Reinforced steel bar strength promotion alloy addition it is more, cause this phenomenon to be more obvious.Therefore, 1) being fully cooled makes it in heating process It is middle to reduce in crack-sensitivity region long-time heating, it avoids expanding cracking trend, if cooling time short will lead to slab high temperature It spends into stove heating, it is too long in crack-sensitivity region heating time;2) slab chilling such as wind or water spray etc., will lead to cooling rate mistake Fastly, it causes to generate excessive internal stress inside slab, so that the operation of rolling the problems such as cracking and irregular deformation is occurred, while because cold Speed is too fast to lead to the compound precipitation exception of V, N inside slab, influences final finished performance.
In slab heating process, the slab after cooling treatment is sent into heating furnace, preheating section, bringing-up section and soaking zone are divided It is heated.Wherein preheating section furnace gas temperature is 850-950 DEG C, such as can be 850 DEG C, 860 DEG C, 870 DEG C, 880 DEG C, 890 DEG C, 900 DEG C, 910 DEG C, 920 DEG C, 930 DEG C, 940 DEG C or 950 DEG C etc.;Bringing-up section furnace gas temperature is 1060-1250 DEG C, such as can Be 1060 DEG C, 1070 DEG C, 1080 DEG C, 1090 DEG C, 1100 DEG C, 1110 DEG C, 1120 DEG C, 1130 DEG C, 1140 DEG C, 1150 DEG C, 1160 DEG C, 1170 DEG C, 1180 DEG C, 1190 DEG C, 1200 DEG C, 1210 DEG C, 1220 DEG C, 1230 DEG C, 1240 DEG C or 1250 DEG C;Soaking zone Furnace gas temperature is 1180-1250 DEG C, such as can be 1180 DEG C, 1200 DEG C, 1230 DEG C or 1250 DEG C etc.;Slab tapping temperature is 1100-1250 DEG C, such as can be 1100 DEG C, 1130 DEG C, 1150 DEG C, 1180 DEG C, 1200 DEG C, 1220 DEG C or 1250 DEG C etc..
The temperature control of above-mentioned heating process be the key that it is of the invention, because carbon content is higher in component system, need to refine each Section temperature control system, so as to avoid decarburization, initial austenite crystal grain is big the problems such as occur;If bringing-up section temperature setting is too low It is unobvious to will lead to insufficient vanadium back dissolving, secondary precipitation of vanadium and nitrogen interaction, reduces gained reinforced steel bar strength.
In rolling process, successively carry out roughing, in roll and finish rolling, water is not worn after rolling.Wherein, start rolling temperature 1100- 1180 DEG C, for example, can be 1100 DEG C, 1110 DEG C, 1120 DEG C, 1130 DEG C, 1140 DEG C, 1150 DEG C, 1160 DEG C, 1170 DEG C or 1180 DEG C etc..
The influence of start rolling temperature, start rolling temperature is directly related with tapping temperature, but start rolling temperature is too low will lead to roll-force Promoted, cause power consumption to improve, such as be more than rolling the limit will lead to roll it is useless;Start rolling temperature is excessively high, causes temperature on cooling table high, influences Subsequent handling.
In cold bed cooling process, temperature on cooling table is 1080-1250 DEG C, such as can be 1080 DEG C, 1100 DEG C, 1120 DEG C, 1140 DEG C, 1160 DEG C, 1180 DEG C, 1200,1220 or 1250 etc.;Lower cold bed temperature is 350-460 DEG C, such as can be 350 DEG C, 380 DEG C, 400 DEG C, 430 DEG C, 450 DEG C or 460 DEG C etc..
The influence of cooling bed tempertaure, reinforcing bar hot-rolled production process belong to ausrolling, start rolling temperature and temperature on cooling table substantially Equal, therefore temperature on cooling table cannot be too low, while temperature on cooling table is excessively high, it is too fast to will lead to cooling rate, generates abnormal structure's shadow Ring finished product comprehensive performance.
Compared with prior art, the present invention is at least had the advantages that
(1) present invention is by compound addition V-N steel, has properly increased containing for carbon and two kinds of cheap elements of nitrogen in steel Amount, is utilized the cooperation of the elements such as synergistic effect and Mn, Si of the elements such as V, C, N, in conjunction with each process temperature in the operation of rolling Control, adequately achieve refined crystalline strengthening and precipitation strength, having obtained tissue is pearlite+ferrite, and grain size >=10 grade Reinforcing bar product, be finally reached 700MPa grades of indexs;
(2) present invention gained reinforcing bar have excellent mechanical property, yield strength >=700MPa, tensile strength >= 850MPa, elongation after fracture A >=14.0%, strong flexor ratio >=1.25, maximum, force percentage of total elongation Agt >=9.0% have good answer Use prospect;
(3) smelting procedure of the present invention does not need special process, easy to operate, rolling mill practice and low-intensity rank screw-thread steel phase Than the requirement of no complexity can carry out large-scale promotion and use.
Detailed description of the invention
Fig. 1 is the metallographic structure figure of 1 gained reinforcing bar of the embodiment of the present invention, and scale is 100 μm;
Fig. 2 is the metallographic structure figure of 1 gained reinforcing bar of the embodiment of the present invention, and scale is 20 μm, in figure: dark-coloured tissue is pearl Body of light, the tissue of light tone are ferrite.
The present invention is described in more detail below.But following examples is only simple example of the invention, not generation Table or limitation the scope of the present invention, protection scope of the present invention are subject to claims.
Specific embodiment
To further illustrate the technical scheme of the present invention below with reference to the accompanying drawings and specific embodiments.
In order to better illustrate the present invention, it is easy to understand technical solution of the present invention, of the invention is typical but non-limiting Embodiment is as follows:
Embodiment 1
Present embodiments provide a kind of preparation method of 700MPa grades of hot rolling high-strength quake-proof reinforcing steel bars of low cost, the preparation side Method comprises the following steps:
(1) smelting procedure: by the process of ingredient, converter smelting, LF refining and continuous casting, obtain 165mm × 165mm's Rectangular slab, based on mass percentage, the chemical component of slab are as follows: C 0.30%, Si 0.40%, Mn 1.21%, V 0.142%, N 0.0210%, surplus are iron and inevitable impurity, wherein S 0.021%, P 0.031%;
(2) slab cooling process: the qualified slab slow cooling that step (1) is obtained through continuous casting is for 24 hours;
(3) slab heating process: step (2) slab after cooling is sent into heating furnace and is heated, wherein preheating section Furnace gas temperature is 850 DEG C, and bringing-up section furnace gas temperature is 1210 DEG C, and soaking zone furnace gas temperature is 1200 DEG C, slab tapping temperature 1165℃;
(4) rolling process: the slab after step (3) heating is rolled using continous way bar wire rod rolling mill, rolling rule Lattice areBlank start rolling temperature be 1145 DEG C, successively carry out roughing, in roll, finish rolling, water is not worn after rolling;
(5) cold bed cooling process: 1150 DEG C of temperature on cooling table of control, 400 DEG C of lower cold bed temperature is cooled down.
Fig. 1 and Fig. 2 is the metallographic structure of gained reinforcing bar.As shown in Figure 1, the crystallite dimension of reinforcing bar is small, 10 grades of grain size >; As shown in Fig. 2, the tissue of reinforcing bar is ferrite and pearlite.
Comprehensive performance inspection is carried out using the method for inspection corresponding in GB/T 28900 to reinforcing bar product obtained by the present embodiment, is taken Four groups are tested,700MPa grades of steel bar mechanics performances are as shown in table 1, and gained reinforcing bar product can be used for mechanical It connects.
Table 1
Embodiment 2
Present embodiments provide a kind of preparation method of 700MPa grades of hot rolling high-strength quake-proof reinforcing steel bars of low cost, the preparation side Method comprises the following steps:
(1) smelting procedure: by the process of ingredient, converter smelting, LF refining and continuous casting, obtain 165mm × 165mm's Rectangular slab, based on mass percentage, the chemical component of slab are as follows: C 0.32%, Si 0.50%, Mn 1.55%, V 0.144%, N 0.031%, surplus are iron and inevitable impurity, wherein S:0.025%, P:0.020%;
(2) slab cooling process: the qualified slab slow cooling that step (1) is obtained through continuous casting is for 24 hours;
(3) heating process: step (2) slab after cooling is sent into heating furnace and is heated, wherein preheating section furnace gas Temperature is 880 DEG C, and bringing-up section furnace gas temperature is 1200 DEG C, and soaking zone furnace gas temperature is 1205 DEG C, 1175 DEG C of slab tapping temperature;
(4) rolling process: the slab after step (3) heating is rolled using continous way bar wire rod rolling mill, rolling rule Lattice areBlank start rolling temperature be 1155 DEG C, successively carry out roughing, in roll, finish rolling, water is not worn after rolling;
(5) cold bed cooling process: 1147 DEG C of temperature on cooling table of control, 425 DEG C of lower cold bed temperature is cooled down.
Comprehensive performance inspection is carried out using the method for inspection corresponding in GB/T 28900 to reinforcing bar product obtained by the present embodiment, is taken Four groups are tested,700MPa grades of steel bar mechanics performances are as shown in table 2, and gained reinforcing bar product can be used for mechanical It connects.
Table 2
Embodiment 3
Present embodiments provide a kind of preparation method of 700MPa grades of hot rolling high-strength quake-proof reinforcing steel bars of low cost, the preparation side Method comprises the following steps:
(1) smelting procedure: by the process of ingredient, converter smelting, LF refining and continuous casting, obtain 165mm × 165mm's Rectangular slab, based on mass percentage, the chemical component of slab are as follows: C 0.32%, Si 0.62%, Mn 1.45%, V 0.175%, N 0.033%, surplus are iron and inevitable impurity, wherein S 0.021%, P 0.027%;
(2) slab cooling process: the qualified slab slow cooling that step (1) is obtained through continuous casting is for 24 hours;
(3) slab heating process: step (2) slab after cooling is sent into heating furnace and is heated, wherein preheating section Furnace gas temperature is 883 DEG C, and bringing-up section furnace gas temperature is 1213 DEG C, and soaking zone furnace gas temperature is 1210 DEG C, slab tapping temperature 1181℃;
(4) rolling process: the slab after step (3) heating is rolled using continous way bar wire rod rolling mill, rolling rule Lattice areBlank start rolling temperature be 1150 DEG C, successively carry out roughing, in roll, finish rolling, water is not worn after rolling;
(5) cold bed cooling process: 1146 DEG C of temperature on cooling table of control, 360 DEG C of lower cold bed temperature is cooled down.
Comprehensive performance inspection is carried out using the method for inspection corresponding in GB/T 28900 to reinforcing bar product obtained by the present embodiment, is taken Four groups are tested,700MPa grades of steel bar mechanics performances are as shown in table 3, and gained reinforcing bar product can be used for mechanical It connects.
Table 3
Embodiment 4
Present embodiments provide a kind of preparation method of 700MPa grades of hot rolling high-strength quake-proof reinforcing steel bars of low cost, the preparation side Method comprises the following steps:
(1) smelting procedure: by the process of ingredient, converter smelting, LF refining and continuous casting, obtain 165mm × 165mm's Rectangular slab, based on mass percentage, the chemical component of slab are as follows: C 0.34%, Si 0.65%, Mn 1.50%, V 0.19%, N 0.037%, surplus are iron and inevitable impurity, wherein S 0.017%, P 0.031%;
(2) slab cooling process: the qualified slab slow cooling that step (1) is obtained through continuous casting is for 24 hours;
(3) slab heating process: step (2) slab after cooling is sent into heating furnace and is heated, wherein preheating section Furnace gas temperature is 890 DEG C, and bringing-up section furnace gas temperature is 1231 DEG C, and soaking zone furnace gas temperature is 1228 DEG C, slab tapping temperature 1198℃;
(4) rolling process: the slab after step (3) heating is rolled using continous way bar wire rod rolling mill, rolling rule Lattice areBlank start rolling temperature be 1170 DEG C, successively carry out roughing, in roll, finish rolling, water is not worn after rolling;
(5) cold bed cooling process: 1167 DEG C of temperature on cooling table of control, 380 DEG C of lower cold bed temperature is cooled down.
Comprehensive performance inspection is carried out using the method for inspection corresponding in GB/T 28900 to reinforcing bar product obtained by the present embodiment, is taken Four groups are tested,700MPa grades of steel bar mechanics performances are as shown in table 4, and gained reinforcing bar product can be used for mechanical It connects.
Table 4
Embodiment 5
Present embodiments provide a kind of preparation method of 700MPa grades of hot rolling high-strength quake-proof reinforcing steel bars of low cost, the preparation side Method comprises the following steps:
(1) smelting procedure: by the process of ingredient, converter smelting, LF refining and continuous casting, obtain 165mm × 165mm's Rectangular slab, based on mass percentage, the chemical component of slab are as follows: C 0.35%, Si 0.80%, Mn 1.60%, V 0.200%, N 0.0400%, surplus are iron and inevitable impurity, wherein S 0.017%, P 0.031%;
(2) slab cooling process: the qualified slab slow cooling that step (1) is obtained through continuous casting is for 24 hours;
(3) slab heating process: step (2) slab after cooling is sent into heating furnace and is heated, wherein preheating section Furnace gas temperature is 943 DEG C, and bringing-up section furnace gas temperature is 1245 DEG C, and soaking zone furnace gas temperature is 1248 DEG C, slab tapping temperature 1195℃;
(4) rolling process: the slab after step (3) heating is rolled using continous way bar wire rod rolling mill, rolling rule Lattice areBlank start rolling temperature be 1183 DEG C, successively carry out roughing, in roll, finish rolling, water is not worn after rolling;
(5) cold bed cooling process: 1179 DEG C of temperature on cooling table of control, 421 DEG C of lower cold bed temperature is cooled down.
Comprehensive performance inspection is carried out using the method for inspection corresponding in GB/T 28900 to reinforcing bar product obtained by the present embodiment, is taken Four groups are tested,700MPa grades of steel bar mechanics performances are as shown in table 5, and gained reinforcing bar product can be used for mechanical It connects.
Table 5
Comparative example 1
This comparative example provides a kind of preparation method of hot rolling high-strength quake-proof reinforcing steel bar, and the preparation method includes following work Sequence:
(1) smelting procedure: by the process of ingredient, converter smelting, LF refining and continuous casting, obtain 165mm × 165mm's Rectangular slab, based on mass percentage, the chemical component of slab are as follows: C 0.37%, Si 0.40%, Mn 1.21%, V 0.142%, N 0.0210%, surplus are iron and inevitable impurity, wherein S 0.021%, P 0.031%;
(2) slab cooling process: the qualified slab slow cooling that step (1) is obtained through continuous casting is for 24 hours;
(3) slab heating process: step (2) slab after cooling is sent into heating furnace and is heated, wherein preheating section Furnace gas temperature is 850 DEG C, and bringing-up section furnace gas temperature is 1210 DEG C, and soaking zone furnace gas temperature is 1200 DEG C, slab tapping temperature 1165℃;
(4) rolling process: the slab after step (3) heating is rolled using continous way bar wire rod rolling mill, rolling rule Lattice areBlank start rolling temperature be 1145 DEG C, successively carry out roughing, in roll, finish rolling, water is not worn after rolling;
(5) cold bed cooling process: 1150 DEG C of temperature on cooling table of control, 400 DEG C of lower cold bed temperature is cooled down.
Comprehensive performance inspection is carried out using the method for inspection corresponding in GB/T 28900 to reinforcing bar product obtained by this comparative example, is taken Four groups are tested,Hot-rolled reinforced bar mechanical property is as shown in table 6, and gained reinforcing bar product can be used for being mechanically coupled.
Table 6
Comparative example 2
This comparative example provides a kind of preparation method of hot rolling high-strength quake-proof reinforcing steel bar, and the preparation method removes step (1) institute State the chemical component of slab are as follows: C 0.28%, Si 0.40%, Mn 1.21%, V 0.135%, N0.0210%, surplus are iron With inevitable impurity, wherein S 0.021%, P 0.031%.Remaining is same as Example 1.
Comprehensive performance inspection is carried out using the method for inspection corresponding in GB/T 28900 to reinforcing bar product obtained by this comparative example, is taken Four groups are tested,Hot-rolled reinforced bar mechanical property is as shown in table 7, and gained reinforcing bar product can be used for being mechanically coupled.
Table 7
By table 1 with the data in table 7 it is found that make when carbon content is lower, preparation-obtained hot rolling high-strength quake-proof reinforcing steel bar Yield strength < 900MPa, yield tensile ratio < 1.25.
Comparative example 3
This comparative example provides a kind of preparation method of hot rolling high-strength quake-proof reinforcing steel bar, and the preparation method removes step (1) institute State the chemical component of slab are as follows: C 0.30%, Si 0.40%, Mn 1.21%, V 0.202%, N0.0210%, surplus are iron With inevitable impurity, wherein S 0.021%, P 0.031%.Remaining is same as Example 1.
Comprehensive performance inspection is carried out using the method for inspection corresponding in GB/T 28900 to reinforcing bar product obtained by this comparative example, is taken Four groups are tested,Hot-rolled reinforced bar mechanical property is as shown in table 8, and gained reinforcing bar product can be used for being mechanically coupled.
Table 8
By the data in table 8 it is found that when the V content in reinforcing bar is more, V contributes more precipitation intensity, gained steel Yield strength >=900MPa of muscle, but strong flexor ratio is reduced to < 1.25.
Comparative example 4
This comparative example provides a kind of preparation method of hot rolling high-strength quake-proof reinforcing steel bar, and the preparation method removes step (1) institute State the chemical component of slab are as follows: C 0.30%, Si 0.40%, Mn 1.21%, V 0.135%, N0.0180%, surplus are iron With inevitable impurity, wherein S 0.021%, P 0.031%.Remaining is same as Example 1.
Comprehensive performance inspection is carried out using the method for inspection corresponding in GB/T 28900 to reinforcing bar product obtained by this comparative example, is taken Four groups are tested,Hot-rolled reinforced bar mechanical property is as shown in table 9, and gained reinforcing bar product can be used for being mechanically coupled.
Table 9
By the data in table 9 it is found that when the content of V in reinforcing bar is less, the V-N steel declines of V, gained heat Roll the yield strength < 900MPa of high-strength quake-proof reinforcing steel bar.
Comparative example 5
This comparative example provides a kind of preparation method of hot rolling high-strength quake-proof reinforcing steel bar, and the preparation method removes step (1) institute State the chemical component of slab are as follows: C 0.30%, Si 0.40%, Mn 1.21%, V 0.142%, N0.0420%, surplus are iron With inevitable impurity, wherein S 0.021%, P 0.031%.Remaining is same as Example 1.
Comprehensive performance inspection is carried out using the method for inspection corresponding in GB/T 28900 to reinforcing bar product obtained by this comparative example, is taken Four groups are tested,Hot-rolled reinforced bar mechanical property is as shown in table 10, and gained reinforcing bar product can be used for being mechanically coupled.
Table 10
By the data in table 10 it is found that when the N content in reinforcing bar is excessively high, the free nitrogen content in reinforcing bar increases, and makes institute The tough brittle transition temperature for obtaining hot rolling high-strength quake-proof reinforcing steel bar improves, and the plasticity index of gained hot rolling high-strength quake-proof reinforcing steel bar is caused to become Difference, elongation after fracture A < 14, maximum, force percentage of total elongation < 9.0%.
Comparative example 6
This comparative example provides a kind of preparation method of hot rolling high-strength quake-proof reinforcing steel bar, and the preparation method removes step (1) institute State the chemical component of slab are as follows: C 0.30%, Si 0.40%, Mn 1.21%, V 0.142%, N0.0180%, surplus are iron With inevitable impurity, wherein S 0.021%, P 0.031%.Remaining is same as Example 1.
Comprehensive performance inspection is carried out using the method for inspection corresponding in GB/T 28900 to reinforcing bar product obtained by this comparative example, is taken Four groups are tested,Hot-rolled reinforced bar mechanical property is as shown in table 11, and gained reinforcing bar product can be used for being mechanically coupled.
Table 11
By the data in table 11 it is found that when the content of nitrogen in reinforcing bar is lower, enough VN chemical combination can not be formed in reinforcing bar The precipitation strength of object, V acts on insufficient, the yield strength < 700MPa of gained hot rolling high-strength quake-proof reinforcing steel bar.
Comparative example 7
This comparative example provides a kind of preparation method of hot rolling high-strength quake-proof reinforcing steel bar, and the preparation method is slow except step (2) The cold time is outside 18h, remaining is same as Example 1.
Comprehensive performance inspection is carried out using the method for inspection corresponding in GB/T 28900 to reinforcing bar product obtained by this comparative example, is taken Four groups are tested,Steel bar mechanics performance is as shown in table 12.
Table 12
By the data in table 12 it is found that when slow cooling fast speed, abnormal structure is generated in gained hot-rolled high-strength reinforcing bar, Lead to the maximum, force percentage of total elongation < 9.0% of gained hot-rolled high-strength reinforcing bar.
In conclusion the present invention by compound addition V-N steel, has properly increased carbon and two kinds of nitrogen cheap members in steel The content of element, is utilized the cooperation of the elements such as synergistic effect and Mn, Si of the elements such as V, C, N, in conjunction with work each in the operation of rolling The control of sequence temperature, adequately achieves refined crystalline strengthening and precipitation strength, has obtained tissue as pearlite+ferrite, and grain size >=10 grades of reinforcing bar product is finally reached 700MPa grades of indexs;Gained reinforcing bar have excellent mechanical property, yield strength >= 700MPa, tensile strength >=850MPa, elongation after fracture A >=14.0%, strong flexor ratio >=1.25, maximum, force percentage of total elongation Agt >= 9.0%, it has a good application prospect;And smelting procedure of the present invention does not need special process, it is easy to operate, rolling mill practice with Low-intensity rank screw-thread steel is compared, and the requirement of no complexity can carry out large-scale promotion and use.
The preferred embodiment of the present invention has been described above in detail, still, during present invention is not limited to the embodiments described above Detail within the scope of the technical concept of the present invention can be with various simple variants of the technical solution of the present invention are made, this A little simple variants all belong to the scope of protection of the present invention.
It is further to note that specific technical features described in the above specific embodiments, in not lance In the case where shield, can be combined in any appropriate way, in order to avoid unnecessary repetition, the present invention to it is various can No further explanation will be given for the combination of energy.
In addition, various embodiments of the present invention can be combined randomly, as long as it is without prejudice to originally The thought of invention, it should also be regarded as the disclosure of the present invention.

Claims (10)

1. a kind of low cost 700MPa grades of hot rolling high-strength quake-proof reinforcing steel bars of hot rolling, which is characterized in that described based on mass percentage Reinforcing bar is composed of the following components: C 0.30-0.35%, V 0.14-0.20%, Si 0.40-0.80%, Mn 1.20-1.60%, N 200-400ppm, surplus are Fe and inevitable impurity.
2. low cost 700MPa grades of hot rolling high-strength quake-proof reinforcing steel bars of hot rolling as described in claim 1, which is characterized in that when the steel When muscle is mechanically coupled, based on mass percentage, the content of C is 0.25-0.30% in the reinforcing bar, and the content of V is 0.16- 0.18%.
3. low cost 700MPa grades of hot rolling high-strength quake-proof reinforcing steel bars of hot rolling as claimed in claim 1 or 2, which is characterized in that described Inevitable impurity content≤350ppm in reinforcing bar.
4. low cost 700MPa grades of hot rolling high-strength quake-proof reinforcing steel bars of hot rolling as claimed in claim 3, which is characterized in that press quality hundred Divide content meter, S≤0.035% in the reinforcing bar, P≤0.035%.
5. reinforcing bar according to any one of claims 1-4, which is characterized in that the reinforcement yielding intensity >=700MPa, tension Intensity >=850MPa, elongation after fracture A >=14.0%, strong flexor ratio >=1.25, maximum, force percentage of total elongation Agt >=9.0%, organize be Pearlite+ferrite, grain size >=10 grade.
6. the preparation method of reinforcing bar as described in any one in claim 1-5, which is characterized in that the preparation method includes following The process successively carried out: converter smelting, LF refining, continuous casting, slab cooling, slab heating, rolling and cold bed are cooling.
7. preparation method as claimed in claim 6, which is characterized in that the slab cooling is slow cooling, time >=for 24 hours.
8. preparation method as claimed in claims 6 or 7, which is characterized in that the slab heating process includes preheating section, heating Section and soaking zone, wherein the preheating section furnace gas temperature is 850-950 DEG C, and the bringing-up section furnace gas temperature is 1060-1250 DEG C, the soaking zone furnace gas temperature is 1180-1250 DEG C, and slab tapping temperature is 1100-1250 DEG C.
9. such as the described in any item preparation methods of claim 6-8, which is characterized in that the rolling process includes successively carrying out Roughing, in roll and finish rolling;
Preferably, start rolling temperature is 1100-1180 DEG C in the rolling process.
10. preparation method as claim in any one of claims 6-9, which is characterized in that in the cold bed cooling process, upper cold bed Temperature is 1080-1250 DEG C, and lower cold bed temperature is 350-460 DEG C.
CN201910804154.9A 2019-08-28 2019-08-28 700MPa grades of hot rolling high-strength quake-proof reinforcing steel bars of a kind of inexpensive hot rolling and preparation method thereof Pending CN110396643A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201910804154.9A CN110396643A (en) 2019-08-28 2019-08-28 700MPa grades of hot rolling high-strength quake-proof reinforcing steel bars of a kind of inexpensive hot rolling and preparation method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201910804154.9A CN110396643A (en) 2019-08-28 2019-08-28 700MPa grades of hot rolling high-strength quake-proof reinforcing steel bars of a kind of inexpensive hot rolling and preparation method thereof

Publications (1)

Publication Number Publication Date
CN110396643A true CN110396643A (en) 2019-11-01

Family

ID=68329504

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201910804154.9A Pending CN110396643A (en) 2019-08-28 2019-08-28 700MPa grades of hot rolling high-strength quake-proof reinforcing steel bars of a kind of inexpensive hot rolling and preparation method thereof

Country Status (1)

Country Link
CN (1) CN110396643A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111172459A (en) * 2020-01-19 2020-05-19 江苏省沙钢钢铁研究院有限公司 HRB600E vanadium-titanium microalloyed high-strength anti-seismic hot-rolled steel bar
CN111850395A (en) * 2020-06-30 2020-10-30 江苏省沙钢钢铁研究院有限公司 N-reinforced high-strength anti-seismic reinforcing steel bar and production method thereof
CN111893371A (en) * 2020-07-18 2020-11-06 钢铁研究总院 Method for improving yield ratio qualification rate of high-strength hot-rolled ribbed steel bar
CN112267071A (en) * 2020-09-30 2021-01-26 江苏永钢集团有限公司 High-strength deformed steel bar for building and production method thereof
CN112458357A (en) * 2020-10-22 2021-03-09 河钢股份有限公司承德分公司 700 MPa-level hot-rolled spiral steel and production method thereof

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108342641A (en) * 2018-01-11 2018-07-31 河钢股份有限公司承德分公司 A kind of 630MPa grades of hot rolling high-strength quake-proof reinforcing steel bar and its production method

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108342641A (en) * 2018-01-11 2018-07-31 河钢股份有限公司承德分公司 A kind of 630MPa grades of hot rolling high-strength quake-proof reinforcing steel bar and its production method

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
倪红军 黄明宇: "《工程材料》", 31 August 2016, 东南大学出版社 *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111172459A (en) * 2020-01-19 2020-05-19 江苏省沙钢钢铁研究院有限公司 HRB600E vanadium-titanium microalloyed high-strength anti-seismic hot-rolled steel bar
CN111850395A (en) * 2020-06-30 2020-10-30 江苏省沙钢钢铁研究院有限公司 N-reinforced high-strength anti-seismic reinforcing steel bar and production method thereof
CN111893371A (en) * 2020-07-18 2020-11-06 钢铁研究总院 Method for improving yield ratio qualification rate of high-strength hot-rolled ribbed steel bar
CN112267071A (en) * 2020-09-30 2021-01-26 江苏永钢集团有限公司 High-strength deformed steel bar for building and production method thereof
CN112458357A (en) * 2020-10-22 2021-03-09 河钢股份有限公司承德分公司 700 MPa-level hot-rolled spiral steel and production method thereof

Similar Documents

Publication Publication Date Title
CN110396643A (en) 700MPa grades of hot rolling high-strength quake-proof reinforcing steel bars of a kind of inexpensive hot rolling and preparation method thereof
CN110408845A (en) A kind of vanadium micro-alloying hot rolling 700MPa grade high-strength reinforcing bar and preparation method thereof
CN100467652C (en) Easy-weld hardening high-strength steel plate and production method thereof
CN103266287A (en) Medium-carbon ferrite-pearlite non-quenched and tempered steel and manufacturing method thereof
CN109252097B (en) Non-quenched and tempered steel of high-strength expansion-fracture connecting rod and continuous casting production process thereof
CN105506494B (en) A kind of yield strength 800MPa grade high ductilities hot-rolling high-strength steel and its manufacture method
CN102618792A (en) High-strength abrasion-resistant steel for engineering machinery and manufacturing method thereof
WO2017117884A1 (en) High carbon steel wire having excellent fine steel cord drawing processability and manufacturing method therefor
CN102345066B (en) Steel used for pressure container and preparation method thereof
CN101717893A (en) 55Si2MnVNbN spring steel and production process thereof
CN103014526A (en) Martensitic stainless steel for valve and manufacturing method thereof
CN106811700B (en) A kind of think gauge acid-resisting X60MS hot-rolled coils and its manufacture method
CN103981449A (en) Method for manufacturing low-alloy high-ductility wear-resistant cast steel by utilizing electric arc furnace
CN106319336A (en) Low-carbon high-chromium abrasion-resistant ball and preparation technique thereof
WO2019029533A1 (en) Cast steel, preparation method for cast steel and use of cast steel
CN110306116A (en) A kind of plus ferro-silicon nitride HRB600 high-strength hot rolled ribbed steel bar and its manufacturing method
CN102029305A (en) Production method of ultra-thick steel plate
CN107326304A (en) A kind of TMCP types surrender 500MPa grades of bridge steel plates and production method
CN103882330B (en) A kind of low yield strength ratio superhigh intensity non-quenched and tempered steel plate and production method thereof
CN105624562A (en) Steel for ultra-high-strength sucker rod and production method thereof
WO2021139505A1 (en) Fabrication method for 600 mpa-grade fine-grain anti-seismic rebar
CN109097680B (en) Method for manufacturing high-manganese high-aluminum nonmagnetic steel plate smelted by 50t intermediate frequency induction furnace
CN104711479B (en) Alloy steel plate for pressure vessel and manufacturing method of alloy steel plate
CN103451554B (en) A kind of clack box metallic substance and preparation method thereof
CN103966515A (en) Method for preparing low-alloy high-strength high-toughness cast steel by virtue of electric arc furnace

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination