CN103498099B - The thick steel plates of a kind of low temperature aging excellent performance and manufacture method thereof - Google Patents
The thick steel plates of a kind of low temperature aging excellent performance and manufacture method thereof Download PDFInfo
- Publication number
- CN103498099B CN103498099B CN201310391500.8A CN201310391500A CN103498099B CN 103498099 B CN103498099 B CN 103498099B CN 201310391500 A CN201310391500 A CN 201310391500A CN 103498099 B CN103498099 B CN 103498099B
- Authority
- CN
- China
- Prior art keywords
- steel
- less
- rolling
- temperature
- low 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.)
- Active
Links
Landscapes
- Heat Treatment Of Steel (AREA)
Abstract
The invention provides the thick steel plates of a kind of low temperature aging excellent performance and manufacture method thereof.The thick steel plates of described low temperature aging excellent performance is made up of the chemical composition of following percentage by weight: less than the C of 0.20wt%；Si less than 0.50wt%；Mn less than 1.60wt%；Nb0.020wt%～0.050wt%；Ti0.010wt%～0.050wt%；Als0.015wt%～0.050wt%；P less than 0.015wt%；S less than 0.012wt%；All the other are Fe and inevitable impurity.By low-carbon microalloyed, and controlled rolling and controlled cooling and control normalized treatment, make steel plate good low temperature timeliness impact property.The thick steel plates of the low temperature aging excellent performance according to the present invention meets-50 DEG C of low-temperature impact work requirements before and after timeliness and even tissue, and properties is excellent, meets ultrasonic examination requirement, meets the requirement of offshore oil platform structural steel and iron.
Description
Technical field
The invention belongs to metallurgical technology field, be specifically related to thick steel plates and the manufacture method thereof of a kind of low temperature aging excellent performance.
Background technology
The use specification of offshore platform structural steel and iron is generally 60mm～80mm, the course of processing to stand include cold to rectify, roll bending, mold pressing, crimping and curved etc. the cold working plastic deformation of flanging, in cold working process, strain-aging owing to occurring can make armor plate strength rise, and plasticity and toughness decline.Research shows, when accelerated ag(e)ing, often increase by 1% is hardening, the ductile-brittle transition temperature of steel plate can raise 5 DEG C, therefore, in order to ensure the stable of steel plate in use performance and safety in utilization, low temperature aging impact flexibility is the indispensable inspection project of offshore platform structural steel and iron.
In steelmaking process, substantial amounts of impurity element can be brought in converter by the steelmaking feeds such as molten iron, steel scrap and ferroalloy, in steel smelting procedure, a part of impurity such as P and S can be reduced to less than or equal to 0.015wt% with less than or equal within the scope of 0.012wt% respectively, but still some impurity such as Cu, As, Sn, Sb etc. by final residue in steel, the impurity element that generally this part remains in steel is referred to as residual elements.The existence of above-mentioned residual elements in steel, especially produces adverse effect to the low-temperature flexibility before and after strain-aging to steel performance.Additionally, when steel plate generation strain-aging, there is dislocation owing to giving longitudinal stretching strain in C and the N in steel, so that steel plate yield strength rises and low-temperature impact toughness declines.
The S355NL related in European standard EN10025-3:2004 " the solderable fine grained structural steel of normalizing/normalizing rolling ", it is widely used in offshore platform and structural member makes.The chemical composition of S355NL and mechanical property requirements are as shown in Table 1 and Table 2.
The chemical composition (wt%) of table 1S355NL
The mechanical property requirements of table 2S355NL
S335NL, except material needs to meet conventional mechanical property, because the difference of the condition of use and application, also needs to meet the various additional requirements such as strain-aging performance.Therefore it is accomplished by the basis of above-mentioned European standard, enhances product performance further.
Summary of the invention
The present invention is the shortcoming in order to overcome above-mentioned prior art to exist and proposes, and the invention provides the thick steel plates of a kind of low temperature aging excellent performance and manufacture method thereof.Before and after the thick steel plates strain-aging of the low temperature aging excellent performance according to the present invention, low-temperature impact toughness is excellent, and meets the standard-required of corresponding kind.
In order to realize one object of the present invention, it is provided that the thick steel plates of a kind of low temperature aging excellent performance, the thick steel plates of described low temperature aging excellent performance is made up of the chemical composition of following percentage by weight: less than the C of 0.20wt%；Si less than 0.50wt%；Mn less than 1.60wt%；Nb0.020wt%～0.050wt%；Ti0.010wt%～0.050wt%；Als0.015wt%～0.050wt%；P less than 0.015wt%；S less than 0.012wt%；All the other are Fe and inevitable impurity.
Preferably, the thick steel plates of described low temperature aging excellent performance is made up of the chemical composition of following percentage by weight: C0.13wt%～0.17wt%；Si0.20wt%～0.50wt%；Mn1.20wt%～1.50wt%；Nb0.030wt%～0.045wt%；Ti0.010wt%～0.035wt%；Als0.020wt%～0.050wt%；P0.008wt%～0.012wt%；S0.005wt%～0.008wt%；All the other are Fe and inevitable impurity.
In order to realize another object of the present invention, it is provided that the manufacture method of the thick steel plates of a kind of low temperature aging excellent performance, described manufacture method includes: steel making working procedure；Refining procedure, control the percentage by weight of the impurity component in refine endpoint molten steel and micro alloying element, wherein, by the control of the percentage by weight of the impurity component in refine endpoint molten steel it is: C0.13wt%～0.17wt%, P0.008wt%～0.012wt%, S0.005wt%～0.008wt%, residual elements As+Sn+Sb≤0.30wt%, by the control of the percentage by weight of the micro alloying element in refine endpoint molten steel it is: Nb0.030wt%～0.045wt%, Ti0.010wt%～0.035wt%, Als0.020wt%～0.040wt%；Continuous casting working procedure；Rolling process, the strand obtained by continuous casting rolls after being heated to the temperature of 1150 DEG C～1200 DEG C, rolling process is divided into austenite recrystallization temperature region and non-recrystallization temperature province two-phase control rolling, wherein, in the rolling in austenite recrystallization temperature region, controlling steel plate mean temperature is 900 DEG C～1200 DEG C, implementing accumulation reduction ratio is the rolling of 50%～55%, in the rolling of non-recrystallization temperature province, controlling steel plate mean temperature is 800 DEG C～890 DEG C, and implementing accumulation reduction ratio is the rolling of 45%～50%；Refrigerating work procedure, carries out weak water-cooled, and opening cold mean temperature is 790 DEG C～810 DEG C, and cold mean temperature is 650 DEG C～710 DEG C eventually, and rate of cooling is 6 DEG C/s～12 DEG C/s；Heat treatment step, is 50 DEG C～100 DEG C by steel plate stacking slow cooling to surface temperature, and at Ac3More than transformation temperature the temperature province of 30 DEG C～50 DEG C carries out normalized treatment, and wherein, the thick steel plates of the low temperature aging excellent performance prepared is made up of the chemical composition of following percentage by weight: less than the C of 0.20wt%；Si less than 0.50wt%；Mn less than 1.60wt%；Nb0.020wt%～0.050wt%；Ti0.010wt%～0.050wt%；Als0.015wt%～0.050wt%；P less than 0.015wt%；S less than 0.012wt%；All the other are Fe and inevitable impurity.
According to the present invention, before described steel making working procedure, also include hot metal pre process procedures, in hot metal pre process procedures, by desulfurizing iron, make the sulfur content in molten iron control at below 0.015wt%, control temperature be more than or equal to 1250 DEG C, the complete slag scratching clean molten iron surface of desulfurization.
According to the present invention, in described steel making working procedure, adopt top and bottom combined blown converter smelting, pretreated molten iron is entered converter, slag material 1min～5min before terminal adds, it is 3.0～5.0 that finishing slag basicity controls, the terminal pressure rifle time is 30 seconds～120 seconds, adopt aluminum manganese titanium deoxidation, the addition of aluminum manganese titanium is 1.5kg/t～4.5kg/t, 3.1kg/t～5.4kg/t desulfurizing agent is added along steel stream during tapping, it is initially added into from when putting steel 1/2, add to when putting steel 3/4, when molten steel goes out to 1/4～3/4, it is dividedly in some parts high manganeisen, at least one in ferro-silico-manganese and ferrocolumbium, during control converter tapping, the percentage by weight of carbon is less than or equal to 0.17wt%.Wherein, described high manganeisen is the ferroalloy that percentage by weight is 55wt%～75wt% of Fe content, and the addition of high manganeisen is 2kg/t～6kg/t；Described ferro-silico-manganese is the ferroalloy of percentage by weight respectively 13wt%～25wt% and 55wt%～75wt% of silicone content and Fe content, and the addition of ferro-silico-manganese is 15kg/t～22kg/t；Described ferrocolumbium is the ferroalloy that percentage by weight is 50wt%～65wt% of content of niobium, and the addition of ferrocolumbium is 0.5kg/t～1.4kg/t.
According to the present invention, described refining procedure includes LF refine and RH refine, in LF refine, adopts omnidistance Bottom Argon Stirring, CaFe line was fed before soft blow argon, feed quantity is 1.6kg/t～3.1kg/t, and the time of soft blow argon is 9min～15min, adds Calx and carries out slag making, aluminum shot deoxidizer is adopted to carry out deoxidation, departures sinciput slag is necessary for HUANGBAI(sic) slag or white slag, and the retention time is 10min～30min, and it is 2.0～4.0 that finishing slag basicity controls；In RH refine, the vacuum in vacuum tank is lower than 133MPa, and when RH application of vacuum, controlling pure degassing time is 3min～12min.
According to the present invention, in described refining procedure, it is possible to by adding the content of at least one micro alloying element controlled in refine endpoint molten steel in ferrocolumbium, ferro-titanium and aluminum metal.Described ferro-titanium includes titanium wire, and the addition of titanium wire is 0.8kg/t～3.1kg/t；Described aluminum metal includes aluminum shot and/or aluminum steel, and the addition of aluminum metal is 1.5kg/t～3.1kg/t.
According to the present invention, in described continuous casting working procedure, adopting whole process protection cast, carbon covering slag in covering slag employing, two water-cooleds adopt weak chill formulas, and casting blank stacking slow cooling is sent after 36～48 hours again and rolled, and wherein, the chemical composition of described middle carbon covering slag is: SiO225wt%～35wt%；CaO35wt%～45wt%；MgO1.90wt%～3.00wt%；Al2O33.00wt%～4.00wt%.
According to the present invention, in described rolling process, in the operation of rolling in austenite recrystallization temperature region, when trimmed size is 60mm～70mm, workpiece thickness is 120mm～150mm, and when trimmed size is 70mm～80mm, workpiece thickness is 130mm～160mm, in the operation of rolling of non-recrystallization temperature province, start rolling temperature is 850 DEG C～890 DEG C；In described refrigerating work procedure, cold mean temperature is 670 DEG C～690 DEG C eventually, and rate of cooling is 7 DEG C/s～10 DEG C/s；In described heat treatment step, in the temperature province of 850 DEG C～870 DEG C, carry out normalized treatment.
Therefore, the manufacture method according to the thick steel plates of the low temperature aging excellent performance of the present invention, by improving operation to reduce the C content in steel, thus effectively reducing the black brittleness of steel；By improving steel-making, refining procedure, effectively control and reduce P, S content, reducing the black brittleness of steel；Tapping process adds appropriate niobium, titanium and aluminum, these micro alloying elements are combined into stable compound with C, the N in steel, can reducing the free nitrogen even eliminating in steel, thus reducing the strain aging sensitivity of steel, the compound of precipitation can improve intensity and crystal grain thinning；Accelerate cooling after rolling, be changed into the transition temperature of ferrite and pearlite reducing austenite；Before and after plate strain timeliness, low-temperature impact toughness is excellent, and armor plate strength meets the standard-required of corresponding kind, it is possible to the steel construction as offshore oil platform etc. uses.
Additionally, the thick steel plates of the low temperature aging excellent performance according to the present invention, after giving the strain of 5% again 250 DEG C implement the Ageing Treatment of 1 hour, meet-50 DEG C of low-temperature impact work requirements before and after timeliness, and even tissue, properties is excellent, meets ultrasonic examination requirement, meets the requirement of offshore oil platform structural steel and iron.
Accompanying drawing explanation
Fig. 1 shows the nearly surface texture metallograph of the thick steel plates of the low temperature aging excellent performance that thickness according to an embodiment of the invention is 75mm.
Fig. 2 shows 1/4 thickness tissue metallograph of the thick steel plates of the low temperature aging excellent performance that thickness according to an embodiment of the invention is 75mm.
Fig. 3 shows 1/2 thickness tissue metallograph of the thick steel plates of the low temperature aging excellent performance that thickness according to an embodiment of the invention is 75mm.
Detailed description of the invention
The invention provides the thick steel plates of a kind of low temperature aging excellent performance, the thick steel plates of described low temperature aging excellent performance is made up of the chemical composition of following percentage by weight: less than the C of 0.20wt%；Si less than 0.50wt%；Mn less than 1.60wt%；Nb0.020wt%～0.050wt%；Ti0.010wt%～0.050wt%；Als(dissolved aluminum) 0.015wt%～0.050wt%；P less than 0.015wt%；S less than 0.012wt%；All the other are Fe and inevitable impurity.The thickness specification of the thick steel plates of the low temperature aging excellent performance according to the present invention is generally 60mm～80mm.
The thick steel plates of the low temperature aging excellent performance according to the present invention, the effect of its each chemical composition is: C is conventional solution strengthening element, while improving intensity, the fragility of steel can be increased, and owing to residual elements increase the fragility of steel, C superposes with residual elements and the black brittleness causing steel is significantly increased, and therefore effectively controls the C content in steel, it is possible to effectively improve the low-temperature flexibility of steel；P is solution strengthening element, can increase the black brittleness of steel, if S too high levels, can form sulphide inculsion, increases the black brittleness of steel, therefore, efficiently controls and reduces the content of P and S and can reduce the black brittleness of steel；Steel adds Nb, Ti and Al micro alloying element, precipitation strength and the refined crystalline strengthening of these micro alloying elements can be passed through, make up the loss of strength that carbon drop brings, thus keeping and improve the intensity of steel, simultaneously when in steel, N content is higher, micro alloying element can combine with N, forms N compound, reduce the free nitrogen even eliminating in steel, it is prevented that free nitrogen increases the low temperature strain-age brittleness of steel.
Preferably, the thick steel plates according to the low temperature aging excellent performance of the present invention is made up of the chemical composition of following percentage by weight: C0.13wt%～0.17wt%；Si0.20wt%～0.50wt%；Mn1.20wt%～1.50wt%；Nb0.030wt%～0.045wt%；Ti0.010wt%～0.035wt%；Als0.020wt%～0.050wt%；P0.008wt%～0.012wt%；S0.005wt%～0.008wt%；All the other are Fe and inevitable impurity.
The manufacture method of the thick steel plates of low temperature aging excellent performance according to the present invention is described more fully below.The manufacture method of the thick steel plates of the low temperature aging excellent performance according to the present invention includes steel making working procedure, refining procedure, continuous casting working procedure, rolling process, refrigerating work procedure and heat treatment step.
According to the present invention, before steel making working procedure, also include hot metal pre process procedures, in hot metal pre process procedures, by desulfurizing iron, make the sulfur content in molten iron control at below 0.015wt%, control temperature be more than or equal to 1250 DEG C, the complete slag scratching clean molten iron surface of desulfurization.
According to the present invention, in steel making working procedure, adopt top and bottom combined blown converter smelting, pretreated molten iron is entered converter, slag material 1min～5min before terminal adds, it is 3.0～5.0 that finishing slag basicity controls, the terminal pressure rifle time is 30 seconds～120 seconds, adopt aluminum manganese titanium deoxidation, the addition of aluminum manganese titanium is 1.5kg/t～4.5kg/t, 3.1kg/t～5.4kg/t desulfurizing agent is added along steel stream during tapping, it is initially added into from when putting steel 1/2, add to when putting steel 3/4, when molten steel goes out to 1/4～3/4, it is dividedly in some parts high manganeisen, at least one in ferro-silico-manganese and ferrocolumbium, during control converter tapping, the percentage by weight of carbon is less than or equal to 0.17wt%, wherein, described high manganeisen is the ferroalloy that percentage by weight is 55wt%～75wt% of Fe content, the addition of high manganeisen is 2kg/t～6kg/t；Described ferro-silico-manganese is the ferroalloy of percentage by weight respectively 13wt%～25wt% and 55wt%～75wt% of silicone content and Fe content, and the addition of ferro-silico-manganese is 15kg/t～22kg/t；Described ferrocolumbium is the ferroalloy that percentage by weight is 50wt%～65wt% of content of niobium, and the addition of ferrocolumbium is 0.5kg/t～1.4kg/t.
According to the present invention, in refining procedure, by the control of the percentage by weight of the impurity component in refine endpoint molten steel it is: C0.13wt%～0.17wt%；P0.008wt%～0.012wt%；S0.005wt%～0.008wt%；Residual elements As+Sn+Sb≤0.30wt%.The percentage by weight controlling the micro alloying element in refine endpoint molten steel is: Nb0.030wt%～0.045wt%；Ti0.010wt%～0.035wt%；Als(dissolved aluminum) 0.020wt%～0.040wt%, wherein it is possible to by the content adding at least one micro alloying element regulated in refine endpoint molten steel in ferrocolumbium, ferro-titanium and aluminum metal so that it is meet above-mentioned percentage by weight.Preferably, described ferro-titanium can be titanium wire, and the addition of titanium wire is 0.8kg/t～3.1kg/t；Described aluminum metal can be aluminum shot and/or aluminum steel, and the addition of aluminum metal is 1.5kg/t～3.1kg/t.In the present invention, converter tapping or refining procedure add appropriate ferro-niobium, ferrotianium or aluminum metal, these micro alloying elements are combined into stable compound with C, the N in steel, the strain aging sensitivity of steel can be reduced, and the compound precipitated out can improve intensity and crystal grain thinning, coordinate the change effect to the phase transition temperature of steel, recrystallization temperature of the microalloy precipitate, optimize precipitated phase, it is achieved more excellent obdurability coupling.
According to the present invention, refining procedure can include LF refine and RH refine, in LF refine, adopts omnidistance Bottom Argon Stirring, CaFe line was fed before soft blow argon, feed quantity is 1.6kg/t～3.1kg/t, and the time of soft blow argon is 9min～15min, adds Calx and carries out slag making, aluminum shot deoxidizer is adopted to carry out deoxidation, departures sinciput slag is necessary for HUANGBAI(sic) slag or white slag, and the retention time is 10min～30min, and it is 2.0～4.0 that finishing slag basicity controls.In RH refine, the vacuum in vacuum tank, lower than 133MPa, avoids chemical heating when RH application of vacuum, and controlling pure degassing time is 3min～12min.
According to the present invention; in continuous casting working procedure; molten steel is injected tundish from the mouth of a river of ladle bottom; inject crystallizer by the mouth of a river of tundish bottom, be casting continuously to form slab by crystallizer, adopt whole process protection cast; carbon covering slag in covering slag employing; two water-cooleds adopt weak chill formula, and the slab thickness going out crystallizer is 200-300mm, and casting blank stacking slow cooling is sent after 36～48 hours again and rolled.The chemical composition of described middle carbon covering slag is: SiO225wt%～35wt%；CaO35wt%～45wt%；MgO1.90wt%～3.00wt%；Al2O33.00wt%～4.00wt%.
According to the present invention, in rolling process, the strand obtained by continuous casting rolls after being heated to the temperature of 1150 DEG C～1200 DEG C, rolling process is divided into austenite recrystallization temperature region and non-recrystallization temperature province two-phase control rolling, wherein, in the rolling in austenite recrystallization temperature region, controlling steel plate mean temperature is 900 DEG C～1200 DEG C, implementing accumulation reduction ratio is the rolling of 50%～55%, in the rolling of non-recrystallization temperature province, controlling steel plate mean temperature is 800 DEG C～890 DEG C, and implementing accumulation reduction ratio is the rolling of 45%～50%.
According to the present invention, in refrigerating work procedure, carry out weak water-cooled, opening cold mean temperature is 790 DEG C～810 DEG C, and cold mean temperature is 650 DEG C～710 DEG C eventually, and rate of cooling is 6 DEG C/s～12 DEG C/s, cooling is accelerated after rolling, it is changed into the transition temperature of ferrite and pearlite reducing austenite, for the steel plate of ferrite and pearlite tissue, it is ensured that final cooling temperature changes on initial temperature at bainite structure.
According to the present invention, in heat treatment step, it is 50 DEG C～100 DEG C by steel plate stacking slow cooling to surface temperature, and at Ac3It is more than transformation temperature that the temperature province of 30 DEG C～50 DEG C carries out normalized treatment.
Preferably, in rolling process, in the operation of rolling in austenite recrystallization temperature region, when trimmed size is 60mm～70mm, workpiece thickness is 120mm～150mm, and when trimmed size is 70mm～80mm, workpiece thickness is 130mm～160mm；In the operation of rolling of non-recrystallization temperature province, start rolling temperature is 850 DEG C～890 DEG C.
Preferably, in refrigerating work procedure, cold mean temperature is 670 DEG C～690 DEG C eventually, and rate of cooling is 7 DEG C/s～10 DEG C/s；In heat treatment step, in the temperature province of 850 DEG C～870 DEG C, carry out normalized treatment.
According to the present invention, by the low cost operation of low-carbon microalloyed, controlled rolling and controlled cooling and control normalized treatment, steel plate is made to have good low temperature aging impact property.The upper yield strength of the thick steel plates of the low temperature aging excellent performance according to the present invention reaches more than 325MPa, tensile strength is 470Mpa～630MPa, meets the requirement to S355NL steel grade in European standard EN10025-3:2004 " the solderable fine grained structural steel of normalizing/normalizing rolling " as shown in table 2.Further ,-50 DEG C of low-temperature impact work monodromes implementing 250 DEG C/1h Ageing Treatment after giving 5% strain again are more than 35J, and meansigma methods is more than 50J.
Hereinafter, embodiments of the invention are described in detail with reference to the attached drawings, but and the scope not limited the present invention in any way.
Embodiment 1:
Manufacture the thick steel plates of the low temperature aging excellent performance of the embodiment 1 with the chemical composition shown in Table 3 below.Wherein, numbering 1 represents that thickness is the steel plate of 63.5mm, and numbering 2 represents that thickness is the steel plate of 75mm.
The chemical composition (wt%) of the thick steel plates of the low temperature aging excellent performance of table 3 embodiment 1
Employing method below manufactures the thick steel plates of the low temperature aging excellent performance of embodiment 1.Specifically, first carry out hot metal pre process procedures, by desulfurizing iron, control the sulfur content in molten iron at 0.012wt%, control temperature at about 1270 DEG C, the complete slag scratching clean molten iron surface of desulfurization.
In steel making working procedure, adopt top and bottom combined blown converter smelting, pretreated molten iron is entered converter, slag material 4min before terminal adds, it is 4.0 that finishing slag basicity controls, the terminal pressure rifle time is 65 seconds, adopt aluminum manganese titanium deoxidation, the addition of aluminum manganese titanium is 3.2kg/t, 4.1kg/t desulfurizing agent is added along steel stream during tapping, it is initially added into from when putting steel 1/2, add to when putting steel 3/4, when molten steel goes out to 1/2, it is dividedly in some parts high manganeisen, ferro-silico-manganese and ferrocolumbium, controlling the percentage by weight of carbon during converter tapping is 0.16wt%, wherein, high manganeisen is the ferroalloy that percentage by weight is 65wt% of Fe content, the addition of high manganeisen is 4kg/t, ferro-silico-manganese is the ferroalloy of percentage by weight respectively 18wt% and the 65wt% of silicone content and Fe content, the addition of ferro-silico-manganese is 18kg/t, ferrocolumbium is the ferroalloy that percentage by weight is 58wt% of content of niobium, the addition of ferrocolumbium is 0.9kg/t.
In refining procedure, by the control of the percentage by weight of the impurity component in refine endpoint molten steel it is: C0.15wt%；P0.011wt%；S0.007wt%；Residual elements As+Sn+Sb=0.015wt%.The percentage by weight controlling the micro alloying element in refine endpoint molten steel is: Nb0.038wt%；Ti0.025wt%；Als(dissolved aluminum) 0.032wt%, regulate the content of the micro alloying element in refine endpoint molten steel by adding the aluminum metal of 2.5kg/t titanium wire and 2.1kg/t so that it is meet above-mentioned percentage by weight.In LF refine, adopt omnidistance Bottom Argon Stirring, CaFe line was fed before soft blow argon, feed quantity is 2.5kg/t, and the time of soft blow argon is 12min, adds Calx and carries out slag making, aluminum shot deoxidizer is adopted to carry out deoxidation, departures sinciput slag is necessary for HUANGBAI(sic) slag or white slag, and the retention time is 20min, and it is 3.0 that finishing slag basicity controls.In RH refine, the vacuum in vacuum tank is 110MPa, avoids chemical heating when RH application of vacuum, and controlling pure degassing time is 10min.
In continuous casting working procedure; molten steel is injected tundish from the mouth of a river of ladle bottom; crystallizer is injected by the mouth of a river of tundish bottom; it is casting continuously to form slab by crystallizer, adopts whole process protection cast, carbon covering slag in covering slag employing; two water-cooleds adopt weak chill formula; the slab thickness going out crystallizer is 300mm, and casting blank stacking slow cooling is sent and rolled for 36 hours, and the chemical composition of middle carbon covering slag is: SiO232wt%；CaO41wt%；MgO2.40wt%；Al2O33.70wt%。
In rolling process, the strand obtained by continuous casting rolls after being heated to the temperature of 1180 DEG C, rolling process is divided into austenite recrystallization temperature region and non-recrystallization temperature province two-phase control rolling, wherein, in the rolling in austenite recrystallization temperature region, controlling steel plate mean temperature is 1050 DEG C, and implementing accumulation reduction ratio is the rolling of 52%, being the steel plate of 63.5mm and 75mm for trimmed size, workpiece thickness is 127mm and 135mm respectively；In the rolling of non-recrystallization temperature province, controlling steel plate mean temperature is 860 DEG C, and start rolling temperature is 860 DEG C, and implementing accumulation reduction ratio is the rolling of 48%.
In refrigerating work procedure, carrying out weak water-cooled, opening cold mean temperature is 800 DEG C, and cold mean temperature is 685 DEG C eventually, and rate of cooling is 8.2 DEG C/s.
In heat treatment step, it is 80 DEG C by steel plate stacking slow cooling to surface temperature, carries out normalized treatment the temperature of 860 DEG C.
Mechanical property and the processing performance of the thick steel plates of the low temperature aging excellent performance of embodiment 1 are shown in table 4.
The mechanical property of the thick steel plates of the low temperature aging excellent performance of table 4 embodiment 1 and processing performance
As can be seen from Table 4, the yield strength of the thick steel plates of the low temperature aging excellent performance of 1 and tension surplus capacity are reasonable according to embodiments of the present invention, and horizontal and vertical low-temperature impact toughness is excellent, and bending rear surface quality is good.
Fig. 1, Fig. 2 and Fig. 3 respectively illustrate the nearly surface of thick steel plates of the low temperature aging excellent performance that thickness is 75mm of embodiment 1,1/4 thickness and 1/2 thickness tissue metallograph.By Fig. 1, Fig. 2 and Fig. 3 it can be seen that the abundant disperse of pearlite after steel plate normalizing, whole thickness direction grain size tends to uniform, and heart portion banded structure is also necessarily improved.
Therefore, according to the present invention, by improving operation to reduce the C content in steel, thus effectively reducing the black brittleness of steel；By improving steel-making, refining procedure, effectively control and reduce P, S content, reducing the black brittleness of steel；Tapping process adds appropriate niobium, vanadium, titanium and aluminum, these micro alloying elements are combined into stable compound with C, the N in steel, can reducing the free nitrogen even eliminating in steel, thus reducing the strain aging sensitivity of steel, the compound of precipitation can improve intensity and crystal grain thinning；Accelerate cooling after rolling, be changed into the transition temperature of ferrite and pearlite reducing austenite；Before and after plate strain timeliness, low-temperature impact toughness is excellent, and armor plate strength meets the standard-required of corresponding kind.
Although in conjunction with the accompanying drawings and embodiments embodiments of the present invention being described in detail above; but; the present invention is not limited to above-mentioned embodiment; those skilled in the art it will be appreciated that; under the premise without departing from present inventive concept; in the scope of claim protection, it is also possible to above-described embodiment is modified or change etc..
Claims (10)
1. a manufacture method for the think gauge offshore platform structural steel and iron of low temperature aging excellent performance, described manufacture method includes:
Steel making working procedure；
Refining procedure, controls the percentage by weight of the impurity component in refine endpoint molten steel and micro alloying element, wherein, by the control of the percentage by weight of the impurity component in refine endpoint molten steel is: C0.13wt%～0.17wt%, P0.008wt%～0.012wt%；S0.005wt%～0.008wt%, residual elements 0 < As+Sn+Sb≤0.30wt%, by the control of the percentage by weight of the micro alloying element in refine endpoint molten steel be: Nb0.030wt%～0.045wt%；Ti0.010wt%～0.035wt%；Als0.020wt%～0.040wt%；
Continuous casting working procedure；
Rolling process, the strand obtained by continuous casting rolls after being heated to the temperature of 1150 DEG C～1200 DEG C, rolling process is divided into austenite recrystallization temperature region and non-recrystallization temperature province two-phase control rolling, wherein, in the rolling in austenite recrystallization temperature region, controlling steel plate mean temperature is 900 DEG C～1200 DEG C, implementing accumulation reduction ratio is the rolling of 50%～55%, in the rolling of non-recrystallization temperature province, controlling steel plate mean temperature is 800 DEG C～890 DEG C, and implementing accumulation reduction ratio is the rolling of 45%～50%；
Refrigerating work procedure, carries out weak water-cooled, and opening cold mean temperature is 790 DEG C～810 DEG C, and cold mean temperature is 650 DEG C～710 DEG C eventually, and rate of cooling is 6 DEG C/s～12 DEG C/s；
Heat treatment step, is 50 DEG C～100 DEG C by steel plate stacking slow cooling to surface temperature, and at Ac3It is more than transformation temperature that the temperature province of 30 DEG C～50 DEG C carries out normalized treatment,
Wherein, the thick steel plates of the low temperature aging excellent performance prepared is made up of the chemical composition of following percentage by weight: less than the C of 0.20wt%；Si less than 0.50wt%；Mn less than 1.60wt%；Nb0.020wt%～0.050wt%；Ti0.010wt%～0.050wt%；Als0.015wt%～0.050wt%；P less than 0.015wt%；S less than 0.012wt%；0 < As+Sn+Sb≤0.30wt%；All the other are Fe and inevitable impurity.
2. manufacture method according to claim 1, it is characterized in that, hot metal pre process procedures is also included before described steel making working procedure, in described hot metal pre process procedures, by desulfurizing iron, make the sulfur content in molten iron control at below 0.015wt%, control temperature be more than or equal to 1250 DEG C, the complete slag scratching clean molten iron surface of desulfurization.
3. manufacture method according to claim 1, it is characterized in that, in described steel making working procedure, adopt top and bottom combined blown converter smelting, pretreated molten iron is entered converter, slag material 1min～5min before terminal adds, it is 3.0～5.0 that finishing slag basicity controls, the terminal pressure rifle time is 30 seconds～120 seconds, adopt aluminum manganese titanium deoxidation, the addition of aluminum manganese titanium is 1.5kg/t～4.5kg/t, 3.1kg/t～5.4kg/t desulfurizing agent is added along steel stream during tapping, it is initially added into from when putting steel 1/2, add to when putting steel 3/4, when molten steel goes out to 1/4～3/4, it is dividedly in some parts high manganeisen, at least one in ferro-silico-manganese and ferro-niobium, during control converter tapping, the percentage by weight of carbon is less than or equal to 0.17wt%, wherein, described high manganeisen is the ferroalloy that percentage by weight is 55wt%～75wt% of Fe content, the addition of high manganeisen is 2kg/t～6kg/t；Described ferro-silico-manganese is the ferroalloy of percentage by weight respectively 13wt%～25wt% and 55wt%～75wt% of silicone content and Fe content, and the addition of ferro-silico-manganese is 15kg/t～22kg/t；Described ferrocolumbium is the ferroalloy that percentage by weight is 50wt%～65wt% of content of niobium, and the addition of ferrocolumbium is 0.5kg/t～1.4kg/t.
4. manufacture method according to claim 3, it is characterised in that described refining procedure includes LF refine and RH refine, in LF refine, adopting omnidistance Bottom Argon Stirring, feed CaFe line before soft blow argon, feed quantity is 1.6kg/t～3.1kg/t, the time of soft blow argon is 9min～15min, adding Calx and carry out slag making, adopt aluminum shot deoxidizer to carry out deoxidation, departures sinciput slag is necessary for HUANGBAI(sic) slag or white slag, and the retention time is 10min～30min, it is 2.0～4.0 that finishing slag basicity controls；In RH refine, the vacuum in vacuum tank is lower than 133MPa, and when RH application of vacuum, controlling pure degassing time is 3min～12min.
5. manufacture method according to claim 1, it is characterised in that in described refining procedure, by adding the content of at least one micro alloying element controlled in refine endpoint molten steel in ferrocolumbium, ferro-titanium and aluminum metal.
6. manufacture method according to claim 5, it is characterised in that described ferro-titanium includes titanium wire, the addition of titanium wire is 0.8kg/t～3.1kg/t；Described aluminum metal includes aluminum shot and/or aluminum steel, and the addition of aluminum metal is 1.5kg/t～3.1kg/t.
7. manufacture method according to claim 1; it is characterized in that; in described continuous casting working procedure; employing whole process protection is poured into a mould; carbon covering slag in covering slag employing, two water-cooleds adopt weak chill formulas, and casting blank stacking slow cooling is sent after 36～48 hours again and rolled; wherein, the chemical composition of described middle carbon covering slag is: SiO225wt%～35wt%；CaO35wt%～45wt%；MgO1.90wt%～3.00wt%；Al2O33.00wt%～4.00wt%.
8. manufacture method according to claim 1, it is characterized in that, in described rolling process, in the operation of rolling in austenite recrystallization temperature region, when trimmed size is 60mm～70mm, workpiece thickness is 120mm～150mm, when trimmed size is 70mm～80mm, workpiece thickness is 130mm～160mm, and in the operation of rolling of non-recrystallization temperature province, start rolling temperature is 850 DEG C～890 DEG C；In described refrigerating work procedure, cold mean temperature is 670 DEG C～690 DEG C eventually, and rate of cooling is 7 DEG C/s～10 DEG C/s；In described heat treatment step, in the temperature province of 850 DEG C～870 DEG C, carry out normalized treatment.
9. the think gauge offshore platform structural steel and iron of a low temperature aging excellent performance, it is characterised in that the think gauge offshore platform structural steel and iron of described low temperature aging excellent performance is made up of the chemical composition of following percentage by weight: less than the C of 0.20wt%；Si less than 0.50wt%；Mn less than 1.60wt%；Nb0.020wt%～0.050wt%；Ti0.010wt%～0.050wt%；Als0.015wt%～0.050wt%；P less than 0.015wt%；S less than 0.012wt%；0 < As+Sn+Sb≤0.30wt%；All the other are Fe and inevitable impurity.
10. the think gauge offshore platform structural steel and iron of low temperature aging excellent performance according to claim 9, it is characterized in that, the think gauge offshore platform structural steel and iron of described low temperature aging excellent performance is made up of the chemical composition of following percentage by weight: C0.13wt%～0.17wt%；Si0.20wt%～0.50wt%；Mn1.20wt%～1.50wt%；Nb0.030wt%～0.045wt%；Ti0.010wt%～0.035wt%；Als0.020wt%～0.050wt%；P0.008wt%～0.012wt%；S0.005wt%～0.008wt%；0 < As+Sn+Sb≤0.30wt%；All the other are Fe and inevitable impurity.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310391500.8A CN103498099B (en) | 2013-09-02 | 2013-09-02 | The thick steel plates of a kind of low temperature aging excellent performance and manufacture method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310391500.8A CN103498099B (en) | 2013-09-02 | 2013-09-02 | The thick steel plates of a kind of low temperature aging excellent performance and manufacture method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103498099A CN103498099A (en) | 2014-01-08 |
| CN103498099B true CN103498099B (en) | 2016-06-29 |
Family
ID=49863356
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310391500.8A Active CN103498099B (en) | 2013-09-02 | 2013-09-02 | The thick steel plates of a kind of low temperature aging excellent performance and manufacture method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103498099B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104630616A (en) * | 2015-02-06 | 2015-05-20 | 铜陵百荣新型材料铸件有限公司 | Silicon-manganese-iron alloy |
| CN106893795B (en) * | 2017-01-17 | 2018-08-28 | 江苏沙钢集团淮钢特钢股份有限公司 | A kind of control globular inclusion smelts the process of ultra-clean steel |
| CN107988557A (en) * | 2017-12-08 | 2018-05-04 | 江苏省沙钢钢铁研究院有限公司 | Ti-added pipeline steel with excellent strain aging performance and preparation method thereof |
| CN110699599B (en) * | 2019-09-25 | 2022-01-11 | 南京钢铁股份有限公司 | Q345R steel for ultralow temperature and manufacturing method thereof |
| CN113604734A (en) * | 2021-07-13 | 2021-11-05 | 莱芜钢铁集团银山型钢有限公司 | Ultra-thick gauge low residual stress forklift steel and preparation method thereof |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2318881C2 (en) * | 2005-12-14 | 2008-03-10 | Открытое акционерное общество "Северсталь" | Strips producing method for making casing tubes |
| CN101210299A (en) * | 2007-12-25 | 2008-07-02 | 莱芜钢铁集团有限公司 | High ductility steel strip for J55 petroleum sleeve and manufacturing method thereof |
| CN102002635A (en) * | 2010-11-29 | 2011-04-06 | 莱芜钢铁股份有限公司 | Steel for pressure container in thick specification and preparation method thereof |
| CN102199725A (en) * | 2011-05-13 | 2011-09-28 | 莱芜钢铁集团有限公司 | Bridge structural steel and production method thereof |
| CN102206788A (en) * | 2011-05-13 | 2011-10-05 | 莱芜钢铁集团有限公司 | Steel and production method thereof |
| CN102212750A (en) * | 2011-05-13 | 2011-10-12 | 莱芜钢铁集团有限公司 | Steel plate for ship structure and manufacture method thereof |
| CN102766806A (en) * | 2012-07-11 | 2012-11-07 | 莱芜钢铁集团有限公司 | Ultrawide and ultrafine gauge structural steel plate for bridges and production method thereof |
-
2013
- 2013-09-02 CN CN201310391500.8A patent/CN103498099B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2318881C2 (en) * | 2005-12-14 | 2008-03-10 | Открытое акционерное общество "Северсталь" | Strips producing method for making casing tubes |
| CN101210299A (en) * | 2007-12-25 | 2008-07-02 | 莱芜钢铁集团有限公司 | High ductility steel strip for J55 petroleum sleeve and manufacturing method thereof |
| CN102002635A (en) * | 2010-11-29 | 2011-04-06 | 莱芜钢铁股份有限公司 | Steel for pressure container in thick specification and preparation method thereof |
| CN102199725A (en) * | 2011-05-13 | 2011-09-28 | 莱芜钢铁集团有限公司 | Bridge structural steel and production method thereof |
| CN102206788A (en) * | 2011-05-13 | 2011-10-05 | 莱芜钢铁集团有限公司 | Steel and production method thereof |
| CN102212750A (en) * | 2011-05-13 | 2011-10-12 | 莱芜钢铁集团有限公司 | Steel plate for ship structure and manufacture method thereof |
| CN102766806A (en) * | 2012-07-11 | 2012-11-07 | 莱芜钢铁集团有限公司 | Ultrawide and ultrafine gauge structural steel plate for bridges and production method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103498099A (en) | 2014-01-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102618792B (en) | High-strength abrasion-resistant steel for engineering machinery and manufacturing method thereof | |
| CN102676920B (en) | Large-thickness steel plate for low-temperature pressure container and production method thereof | |
| CN102400043B (en) | Large-thickness steel plate for oceaneering | |
| CN103498099B (en) | The thick steel plates of a kind of low temperature aging excellent performance and manufacture method thereof | |
| CN107964624A (en) | A kind of yield strength 500MPa level structure steel and preparation method thereof | |
| CN102424933A (en) | Hot-rolled high-strength strip steel and manufacturing method thereof | |
| CN114134430B (en) | High-hardenability 35SiMnCrMoB steel for wear-resistant parts of engineering machinery and manufacturing method thereof | |
| CN111349853B (en) | Rolling method for hot-rolled H-shaped steel by microalloy treatment | |
| CN104928576A (en) | Production method of 260-330MPa low-alloy high-strength steel | |
| CN109385576A (en) | A kind of inexpensive X65 pipe line steel and its manufacturing method based on magnesium processing | |
| CN110578089A (en) | high-strength quenched and tempered steel plate for ocean engineering and production method thereof | |
| CN102268615B (en) | Engineering steel material with excellent core low-temperature impact toughness and lamellar tearing resisting performance and production method thereof | |
| CN104131238B (en) | High molding high durable Ultra-thin hot rolled steel plate and CSP production technology thereof | |
| CN113652609A (en) | Low-cost 42CrMoA round steel and production method thereof | |
| CN108034886A (en) | A kind of low-density lightweight body of tipper carriage wear-resisting steel plate and preparation method thereof | |
| CN114134398A (en) | Expansion-fracture connecting rod steel with yield ratio of 0.70-0.80 and manufacturing method thereof | |
| CN105200329A (en) | Tensile strength-700MPa level easy-to-weld low-internal-stress structural steel plate and manufacturing method thereof | |
| CN114000055A (en) | Boron microalloyed gear steel and preparation method thereof | |
| CN104213022A (en) | Agitation tank steel with tensile strength of 650 MPa grade and production method thereof | |
| CN117144253B (en) | Niobium microalloyed hot rolled ribbed steel bar and production method thereof | |
| CN111270169A (en) | Ni-containing alloy steel plate with excellent low-temperature toughness and production method thereof | |
| CN106521332B (en) | A kind of resistance to stress guiding hydrogen induced cracking (HIC) steel plate and its production method | |
| WO2019029533A1 (en) | Cast steel, preparation method for cast steel and use of cast steel | |
| CN113106334A (en) | Steel for cycloidal gear of RV reducer and preparation method thereof | |
| CN110172638B (en) | High-temperature carburized gear steel and production method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20210715 Address after: 271104 Shuangquan Road, Gangcheng District, Jinan City, Shandong Province Patentee after: LAIGANG GROUP YINSHAN SHAPED STEEL Co.,Ltd. Address before: 271104 No.99, Fuqian street, Gangcheng District, Laiwu City, Shandong Province Patentee before: Laiwu Steel Group Ltd. |
|
| TR01 | Transfer of patent right |