CN102433498B - Q550 D high-quality structural iron medium and heavy plate and production method thereof - Google Patents
Q550 D high-quality structural iron medium and heavy plate and production method thereof Download PDFInfo
- Publication number
- CN102433498B CN102433498B CN2011101784703A CN201110178470A CN102433498B CN 102433498 B CN102433498 B CN 102433498B CN 2011101784703 A CN2011101784703 A CN 2011101784703A CN 201110178470 A CN201110178470 A CN 201110178470A CN 102433498 B CN102433498 B CN 102433498B
- Authority
- CN
- China
- Prior art keywords
- temperature
- steel
- cooling
- molten iron
- slag
- 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 discloses a Q550 D high-quality structural iron medium and heavy plate, produced by smelting and rolling C, Si, Mn, Nb, V, Ti, Mo, B, Als and Fe. According to the invention, by properly adjusting the content and proportion of C, Mn, Nb, V, Ti, and Mo in the Q550D(E), strictly controlling the content of P and S, and cooperating the production technology disclosed herein, the characteristics of low carbon equivalent, high strength, high toughness, good weldability and the like of the structural iron medium and heavy plate can be guaranteed, the production technology can be simplified, the production flow can be shortened, and the production energy consumption can be reduced. The Q550 D high-quality structural iron medium and heavy plate is suitable for large-scale production operation.
Description
Technical field
The invention belongs to steel manufacturing technology field, be specifically related to a kind of Q550D high-quality structural steel plate of moderate thickness and production method thereof.
Background technology
The low-alloy high-strength Wide and Heavy Plates is in the steel industry development policies, clearly to propose to encourage the product of producing.It belongs to the resources conservation structural section, is also more typical high technology content, high value added product simultaneously, is widely used in each key areas of national economy such as the energy, traffic, building, engineering machinery, has very large market potential.Along with the technology upgrading of steel demand industry, the performance of steel is also constantly proposed to new higher requirement.Wide and Heavy Plates is class leading product that belong to plate of moderate thickness in the steel products classification, and general general reference adopts the width of wide and heavy plate mill production more than 3000 mm, the steel plate of thickness more than 4 mm.Because planar dimension and the thickness of Wide and Heavy Plates are all larger, the product suitability of Wide and Thick Slab is strong, higher than other products utilization ratio when making tun, equipment and steel construction, more economical reasonable, therefore by many industry user's wide selection.The low-alloy high-strength Wide and Heavy Plates is mainly used in welded construction, therefore not only requires steel to have high intensity and plasticity and toughness, also good weldability and processes must be arranged.High cleanliness, high strength, high tenacity the Wide and Heavy Plates with good thickness directional properties are total developing direction.High-toughness structural steel Q550D(E) be a kind of micro-alloy low-carbon bainite steel, the characteristics such as it has, and intensity is high, good toughness, excellent in low temperature toughness, processing characteristics and good welding performance.Be mainly used in the fields such as engineering machinery, coal mine machinery, shipbuilding and steel construction.In recent years, the application of Hi-Stren steel is more extensive, but high strength Q550D(E) steel plate is large with its alloy designs and metallurgical technology difficulty, tooling requires the reasons such as special, production cost is high.At present, Some Domestic steel mill adopts TMCP+T to be produced, complex procedures, and, greatly mainly with quality adjustment condition delivery, steel plate is through quenching and tempering 2 road heat treatment steps, not only strict to equipment requirements, increased especially manufacturing cost, seriously restricting the development that these type of steel are manufactured, can't meet the growing market requirement, and then also affect the development of downstream industry and even national economy.
Summary of the invention
The object of the invention is to provide a kind of prior art that can solve and produces high-strong toughness structure iron Q550D(E) complex process, production efficiency is low, the high in cost of production problem, coordinate rational chemical composition design and TMCP rolling technology, replace modified or temper production technique, thereby can guarantee high strength, high tenacity and the good requirements such as welding property, can simplify again production technique, shorten Production Flow Chart, reduce production energy consumption, be applicable to Q550D high-quality structural steel plate of moderate thickness and the production method thereof of large production operation.
Realize that the technical scheme that purpose of the present invention is taked is: a kind of Q550D high-quality structural steel plate of moderate thickness comprises the chemical composition of following mass percent: C:0.03～0.09wt%, Si:0.20～0.40 wt%, Mn:1.30～1.65 wt%, P :≤0.010 wt%, S :≤0.005 wt%, Nb or/and V or/and Ti:0.05～0.20wt%, Mo:0.10～0.20wt%, B:0.05～0.15wt%, Als :≤0.050 wt%, remaining is Fe.
The carbon equivalent of described chemical composition≤0.43.
A kind of processing method of producing described Q550D high-quality structural steel plate of moderate thickness comprises the following steps: high-quality cast iron melting, KR hot metal pretreatment, converter smelting, the refining of LF stove, Fruit storage, continuous casting, heating, rolling and ACC laminar flow are cooling;
In described KR hot metal pretreatment step, the molten iron that arrives at a station must be taken off front slag and take off rear slag, guarantees liquid level thickness of slag layer≤20mm, and molten iron is through the KR stirring desulphurization, desulfurization cycle≤21min, desulfurization temperature drop≤20 ℃, reach in molten iron by mass percentage containing S≤0.005 wt%;
In described converter smelting step, adopt 100/120 ton of top and bottom combined blown converter, enter in the stove molten iron to contain by mass percentage S≤0.005 wt%, contain P≤0.080 wt%, molten iron temperature >=1270 ℃, molten iron Intake Quantity error control is at ± 1t, and slag making basicity R is controlled in the 2.5-4.0 scope, goes out in steel water carbon containing 0.03-0.04wt% by mass percentage, containing P≤0.012wt%, containing S≤0.010 wt%; Point blows number of times and must not be greater than 2 times;
In described LF stove refinement step, omnidistance Argon in refining process, the basicity that adds refining slag is 4.0～6.0, heat-up time is by twice control, heat for the first time 7～12min, heat for the second time 6～10 min, dry slag number of times >=6 time, must close argon gas before adding silicon-calcium wire, not adopting in vacuum outgas the steel temperature is 1565 ± 15 ℃ or to adopt steel temperature in vacuum outgas be 1610 ± 15 ℃;
In described Fruit storage step, VD vacuum tightness≤67Pa, dwell time >=15min, soft blow 2～5min or do not blow after vacuum breaker, in the soft blow process, molten steel must not be exposed, and online ladle vacuumizes 1.7min, close argon gas, add insulating covering agent, and the ensuring coverage agent is paved with the molten steel face, upper steel temperature is controlled at 1565 ± 15 ℃;
In described continuous casting step, the superheating temperature of tundish preheating is controlled at 15 ± 10 ℃, the withdrawal straightening machine pulling rate is controlled at 0.7m/min, and the specific water is 0.80L/ ㎏, and in induction stirring, electromagnetic system control parameter is: 900A, 5Hz, 30s-3-30s, the casting of continuous-casting steel pouring whole process protection, large ladle is opened and is watered rear 1min inner sleeve protective tube, carries out the stopper Argon in steel pouring process, the strand rear stacking slow cooling that rolls off the production line, cooling in heap temperature >=200 ℃, cooling in heap time >=12h;
In described heating steps, heat-processed is carried out segmentation and is controlled, and the preheating section temperature is controlled at 900～1000 ℃, and the heating zone temperature is controlled at 1200～1260 ℃, and rate of heating is controlled at 8～13min/cm, and the holding-zone temperature is controlled at 1180～1240 ℃;
In described rolling step, divide 2 stage rolling, start rolling temperature is controlled at 1100 ℃～1150 ℃, the one-phase finishing temperature is at 950 ℃～1020 ℃, treat that temperature thickness is 2～3 times of finished product thickness, two-stage start rolling temperature≤900 ℃, two-stage bonding percentage pass reduction >=15%, accumulative total draft >=65%, finishing temperature is controlled at 760～860 ℃;
In described ACC laminar flow cooling step, by adjusting cooling manifold group number, speed of cooling is controlled at 5～30 ℃/S, red temperature, between 450～600 ℃, is sent to straightener aligning after laminar flow is cooling, the steel plate rear stacking slow cooling that rolls off the production line, cooling in heap temperature >=200 ℃, cooling in heap time >=24h.
Low-alloy high-strength Wide and Heavy Plates of the present invention, the core of its manufacturing technology is alloy designs and metallurgical technology, the present invention is at traditional Q 550D(E) on the composition basis of high-strong toughness structure iron, the suitable Q550D(E that adjusts) content and the ratio of C, Mn, Nb, V, Ti, Mo alloying element in, strict P, the S content controlled, coordinate production technique of the present invention, make its low-carbon-equivalent that can guarantee steel plate, high strength, high tenacity and the good requirements such as welding property, can simplify again production technique, shorten Production Flow Chart, reduce production energy consumption, be applicable to large production operation.In above-mentioned design, the effect of each chemical element is:
C: be most basic strengthening element in steel, improve intensity, but C affect the welding property of steel and affect toughness, consider, what the content of carbon need be controlled hangs down.
Si: be the solution strengthening element, favourable to the intensity that improves steel plate.
Mn: be the solution strengthening element, all favourable to intensity and the toughness that improves steel plate.
P: unfavorable to welding, and there is certain cold shortness, and belong to harmful element in this steel grade, that should control is as far as possible low.
S: easily form the MnS type impurity, have certain red brittleness, belong to harmful element in this steel grade, that should control is as far as possible low.
V, Nb, Ti: be trace alloying element, can be combined with C, N in steel, form fine carbide or carbonitride, can play crystal grain thinning and dispersion-strengthened action, thereby reach the net effect of the obdurability of effective raising steel.
Mo: be trace alloying element, appropriate add the effect of playing solution strengthening, can effectively reduce γ → α transformation rate, suppress polygonal ferrite and perlite forming core, promote acicular ferrite or the microtexture ULCB forming core of high density dislocation substructure, guarantee the steel plate high-intensity high-tenacity.
Al: can play the grain refining intensificatiom effect.
B: with Nb in steel, form Nb(B) class precipitate, after thermal distortion, in austenite, by strain inducing, on dislocation line, separate out, hinder recrystallize, improve recrystallization temperature, the B atom can greatly hinder cenotype at the grain boundaries forming core at Grain Boundary Segregation, makes proeutectoid ferrite generate district and obviously moves to right.
Q550D high-quality structural steel plate of moderate thickness of the present invention, at traditional Q 550D(E) on the composition basis of high-strong toughness structure iron, the suitable Q550D(E that adjusts) content and the ratio of C, Mn, Nb, V, Ti, Mo alloying element in, strict P, the S content controlled, coordinate production technique of the present invention, make its low-carbon-equivalent that can guarantee steel plate, high strength, high tenacity and the good requirements such as welding property, can simplify again production technique, shorten Production Flow Chart, reduce production energy consumption, be particularly suitable for large production operation.
Embodiment
Q550D high-quality structural steel plate of moderate thickness of the present invention, be by the contriver on the basis of summing up the long-term practice experience, by a large amount of experimental studies, at traditional Q 550D(E) on the composition basis of high-strong toughness structure iron, suitably adjust content and the ratio of C, Mn, Nb, V, Ti, Mo alloying element, smelt by Clean Steel, strictly control P, S content, obtained the low-carbon-equivalent and the weldability that both guarantee steel plate, ensured again Q550D(E) good result of obdurability coupling., in order to simplify Production Flow Chart, reduce production costs simultaneously, inquire into through groping, obtained a kind of TMCP rolling and replaced modified or temper to produce high-strong toughness structure iron Q550D(E) processing method of plate of moderate thickness.This technique can solve traditional general enterprises and produce high-strong toughness structure iron Q550D(E) complex manufacturing, the problems such as cost is higher, there are low cost, short flow process, allegro characteristics, coordinate described rational chemical composition design and ripe TMCP rolling technology, make it can guarantee high strength, high tenacity and the good requirements such as welding property, can simplify again production technique, shorten Production Flow Chart, reduce production energy consumption, be applicable to guaranteed cost, the guarantor's flaw detection of large production operation, width 3800mm, thickness≤50mm.
The chemical composition that described Q550D high-quality structural steel plate of moderate thickness comprises following mass percent: the chemical composition (unit that comprises following mass percent, wt%): C:0.03～0.09wt%, Si:0.20～0.40 wt%, Mn:1.30～1.65 wt%, P :≤0.010 wt%, S :≤0.005 wt%, Nb or/and V or/and Ti:0.05～0.20wt%, Mo:0.10～0.20wt%, B:0.05～0.15wt%, Als :≤0.050 wt%, remaining is Fe.Carbon equivalent [Ceq=C+Mn/6+ (Cr+Mo+V)/5+ (Ni+Cu)/15] :≤0.43.The production technique of Q550D high-quality structural steel plate of moderate thickness of the present invention adopts converter smelting, continuous casting, and the method for 3800m wide and heavy plate mill rolling is produced Q550D(E) the high-strong toughness structural steel and iron.Its technical process is: high-quality molten iron, KR hot metal pretreatment, converter smelting, the refining of LF stove, Fruit storage, continuous casting, pusher-type furnace, 3800m mill milling, ACC laminar flow are cooling, 11 roller thermal straightening machines, cooling in heap, finishing, outer inspection, flaw detection, warehouse-in.Below in conjunction with embodiment, the production method of this high-quality structural steel plate of moderate thickness is described further.
Embodiment 1
Described Q550D high-quality structural steel plate of moderate thickness is manufactured width 3800mm, thickness 50mm, adopt the chemical composition manufacture of following mass percent: C:0.03wt%, Si:0.20 wt%, Mn:1.30 wt%, P:0.010 wt%, S:0.005 wt%, Nb or/and V or/and Ti:0.05 wt%, Mo:0.10 wt%, B:0.05wt%, Als0.050 wt%, remaining is Fe.Carbon equivalent [Ceq=C+Mn/6+ (Cr+Mo+V)/5+ (Ni+Cu)/15]=0.43.Its production method is carried out in the steps below:
1) the high-quality molten iron of open hearth melting is carried out to the KR pre-treatment: must be taken off front slag and take off rear slag when molten iron arrives at a station, the molten iron level thickness of slag layer is 20mm, and carry out the KR stirring desulphurization, the desulfurization cycle is 20 ℃ of 21min, desulfurization temperature drops, and the molten iron after desulfurization is 0.005 wt% containing the S amount by mass percentage.
2) converter smelting: pretreated molten iron is imported to 100/120 ton of top and bottom combined blown converter, must guarantee in the stove molten iron to be that 0.005 wt%, P content are 0.080 wt% containing the S amount by mass percentage, molten iron temperature is 1270 ℃, press ± 1t of molten iron Intake Quantity error controls, steel scrap strictly adopts the high-quality scrap stock, slag making basicity R controlling valu is 2.5, and carbon content 0.035 wt% by mass percentage in the molten steel of coming out of the stove is 0.012 wt%, is 0.010 wt% containing the S mass percent containing the P mass percent; It is 2 times that point blows number of times, to avoid slag under tapping process.
3) LF stove refining: the molten iron of converter smelting is poured in the LF refining furnace, in refining process, must be carried out omnidistance Argon, Argon intensity need to be regulated according to different links.Add the basicity of refining slag by 4.0 controls; The refinement and deoxidation agent be take calcium carbide, aluminum shot, ferrosilicon powder as main, and add-on is according to oxygen level in molten steel and make the white slag situation and add in right amount; Refining heat-processed selects suitable electric current to be heated according to rhythm is more than needed with temperature conditions, and by twice control, heat for the first time 7min heat-up time, heats for the second time 6min, in heat-processed, requires for the second time to add reductor according to the slag making situation; Dry slag number of times 6 times, add silicon-calcium wire before leaving from station, must close argon gas before adding silicon-calcium wire; Upper steel Wen Wendu is 1610 ± 15 ℃.
4) Fruit storage: VD vacuum tightness is 67Pa, and the dwell time is 15min, wraps Bottom Argon Stirring simultaneously, soft blow 2min after vacuum breaker, and in the soft blow process, molten steel must not be exposed.Normal online bag pumpdown time (vacuumizing front liquid steel temperature-target temperature leaving from station) is controlled at 1.7min; Then add insulating covering agent, guarantee to be paved with the molten steel face, must close argon gas before adding insulating covering agent, it is 1565 ± 15 ℃ that upper steel temperature is controlled.
5) continuous casting: before watering steel, guarantee that the casting machine status of equipment is good, the molten steel that refining is good injects tundish by large bag, the superheating temperature of tundish preheating is controlled at 15 ± 10 ℃, the control pulling rate of withdrawal straightening machine is 0.7m/min, the specific water is controlled at 0.80L/ ㎏, and in induction stirring, the electromagnetic control parameter is: 900A, 5Hz, 30s-3-30s; Continuous-casting steel pouring requires omnidistance argon shield casting, unwraps greatly to water in rear 1min and must overlap protective tube, guarantees not show of molten steel face in the basket pouring process; Rationally control stopper Argon amount in steel pouring process, guarantee that liquid level fluctuation of crystallizer is slight; The strand laggard windrow that rolls off the production line is cold, and the cooling in heap temperature is 200 ℃, and the cooling in heap time is 12h.
6) heating: strand is sent in pusher-type furnace and heated, press zone heating: 900 ℃ of preheating section temperature, 1200 ℃ of heating zone temperature, 1180 ℃ of holding-zone temperature, rate of heating is controlled at 8min/cm.
7) rolling: the strand of heating is delivered on the 3800mm milling train and is rolled, in the operation of rolling, for preventing mixed crystal and coarse grains, to strictly adhere to the rolling requirement of " high temperature, low speed, depress greatly ", start rolling temperature is 1100 ℃, the one-phase finishing temperature is 950 ℃, treats that temperature thickness is 2 times of finished product thickness, for finish rolling stage accumulative total deflection and crystal grain thinning, dislocations strengthening lay the foundation; The two-stage start rolling temperature is 900 ℃, two-stage single pass draft is 15%, the accumulative total draft is 65%, guaranteed that thus distortion infiltration makes the elongation that is crushed of the inner crystal grain of austenite, increase the crystal boundary useful area and effectively form a large amount of deformation bands, for austenite phase transformation provides more forming core point, reached the purpose of refine austenite crystal grain, finishing temperature is controlled at 760 ℃.
8) the ACC laminar flow is cooling: in order to obtain good comprehensive mechanical property, according to the difference of thickness of slab, roll the different laminar flow of rear employing cooling, by adjusting cooling manifold group number, controlling speed of cooling is 5 ℃/S, and red temperature is 450 ℃, is sent to the straightener aligning after laminar flow is cooling, stacking slow cooling in time rolls off the production line after steel plates straightening, the cooling in heap temperature is 200 ℃, and the cooling in heap time is 24h, by slow cooling, produce implosion to avoid internal stress to have little time to discharge, further impel the inner obnoxious flavour of steel plate to overflow simultaneously.
Embodiment 2
Described Q550D high-quality structural steel plate of moderate thickness is manufactured width 3800mm, thickness 40mm, adopt the chemical composition manufacture of following mass percent: C:0.06wt%, Si:0.30 wt%, Mn:1.50 wt%, P:0.007wt%, S:0.003wt%, Nb or/and V or/and Ti:0.13 wt%, Mo:0.15 wt%, B:0.10wt%, Als:0.030 wt%, remaining is Fe.Carbon equivalent [Ceq=C+Mn/6+ (Cr+Mo+V)/5+ (Ni+Cu)/15]: 0.40.
Its production method is substantially the same manner as Example 1, and its difference only is: in step 1), the molten iron level thickness of slag layer is 15mm, and the desulfurization cycle is that 18min, desulfurization temperature drop are 18 ℃, and the molten iron after desulfurization is 0.004 wt% containing the S amount by mass percentage; Step 2) in, entering in the stove molten iron is that 0.004 wt%, P content are 0.070 wt% containing the S amount by mass percentage, molten iron temperature is 1300 ℃, slag making basicity R controlling valu is 3.0, the carbon content by mass percentage of coming out of the stove in molten steel is 0.035 wt%, and P content is 0.01 wt%, is 0.008 wt% containing the S amount; It is 2 times that point blows number of times; In step 3), the basicity that adds refining slag is 5.0; Be 9min heat-up time for the first time, is heated to be for the second time 8min, and the dry slag number of times is 7 times; Do not adopt vacuum outgas; In step 5, the strand rear cooling in heap temperature that rolls off the production line is 250 ℃, and the cooling in heap time is 18h; In step 6, the preheating section temperature is 950 ℃, and the heating zone temperature is 1230 ℃, the holding-zone temperature is 1210 ℃, rate of heating is 10min/cm, and in step 7, start rolling temperature is 1130 ℃, the one-phase finishing temperature is 1000 ℃, treat that temperature thickness is 2.5 times of finished product thickness, the two-stage start rolling temperature is 900 ℃, and two-stage single pass draft is 16%, the accumulative total draft is 67%, and finishing temperature is controlled at 800 ℃; In step 8, speed of cooling is 20 ℃/S, and red temperature is 550 ℃, and the cooling in heap temperature is 250 ℃, and the cooling in heap time is 28h.
Embodiment 3
Described Q550D high-quality structural steel plate of moderate thickness is manufactured width 3800mm, thickness 25mm, adopt the chemical composition manufacture of following mass percent: C:0.09wt%, Si:0.40 wt%, Mn:1.65 wt%, P:0.005 wt%, S:0.002wt%, Nb or/and V or/and Ti:0.20 wt%, Mo:0.20 wt%, B:0.15 wt%, Als :≤0.010 wt%, remaining is Fe.Carbon equivalent [Ceq=C+Mn/6+ (Cr+Mo+V)/5+ (Ni+Cu)/15]: 0.38.
Its production method is substantially the same manner as Example 1, and its difference only is: in step 1), the molten iron level thickness of slag layer is 12mm, and the desulfurization cycle is that 16min, desulfurization temperature drop are 14 ℃, and the molten iron after desulfurization is 0.002 wt% containing the S amount by mass percentage; Step 2) in, entering in the stove molten iron is that 0.003 wt%, P content are 0.060 wt% containing the S amount by mass percentage, molten iron temperature is 1360 ℃, slag making basicity R controlling valu is 4.0, carbon content 0.04 wt% by mass percentage that comes out of the stove in molten steel, be 0.008wt%, be 0.006 wt% containing the S mass percent containing the P mass percent; It is 1 time that point blows number of times; In step 3), the basicity that adds refining slag is 6.0; Heat for the first time 12min, heat for the second time 10min, require in heat-processed for the second time to add reductor according to the slag making situation; Dry slag number of times 8 times; In step 4, VD vacuum tightness is 60Pa, and the dwell time is 20min, blowing argon gas not after vacuum breaker; In step 5, the strand rear cooling in heap temperature that rolls off the production line is 300 ℃, and the cooling in heap time is 24h; In step 6, the preheating section temperature is 1000 ℃, and the heating zone temperature is 1260 ℃, and the holding-zone temperature is 1240 ℃, and rate of heating is 13min/cm
;in step 7, start rolling temperature is 1150 ℃, and the one-phase finishing temperature is 1020 ℃, treat that temperature thickness is controlled at 3 times of finished product thickness, the two-stage start rolling temperature is controlled at 900 ℃, and two-stage single pass draft is 18%, the accumulative total draft is 70%, and the finish to gauge finishing temperature is 860 ℃; In step 8, speed of cooling is controlled at 30 ℃/S, and red temperature is 600 ℃, 300 ℃ of cooling in heap temperature, and the cooling in heap time is 36h.
The contriver is respectively to the Q550D(E of 25mm, 40mm, 50mm thickness) more than 70 batches of plate of moderate thickness tests, property indices all reaches standard-required and surplus capacity is larger, wherein yield strength is controlled at 565-650Mpa, on average reach 620 Mpa, tensile strength is controlled at 690-800MPa, on average reaches 760 MPa, and elongation is controlled at 17%-22%, on average reach 19%, than standard affluence 5%;-20 ℃ of V-type ballistic works are controlled at 120～320J, have on average reached 230 J, and-40 ℃ of V-type ballistic works are controlled at 120～245J, have on average reached 160 J, reach Q550D(E fully) standard-required.Steel plate is examined in strict accordance with JB/T 47030 standards outward, and the percentage of A-class goods 100%, detected a flaw by JB/T 47030, and unification level rate is 86%, and closing three grades of rates is 100%, has reached desired result.Mechanical property specifically sees the following form.
Q550D(E) steel plate mechanical mechanics property
Claims (1)
1. a Q550D high-quality structural steel plate of moderate thickness, it is characterized in that: it comprise the chemical composition of following mass percent: C:0.03wt%, Si:0.20 wt%, Mn:1.30 wt%, P:0.010 wt%, S:0.005 wt%, Nb or/and V or/and Ti:0.05 wt%, Mo:0.10 wt%, B:0.05wt%, Als0.050 wt%, remaining is Fe, and its production method is carried out in the steps below:
1) the high-quality molten iron of open hearth melting is carried out to the KR pre-treatment: must be taken off front slag and take off rear slag when molten iron arrives at a station, the molten iron level thickness of slag layer is 20mm, and carry out the KR stirring desulphurization, the desulfurization cycle is 20 ℃ of 21min, desulfurization temperature drops, and the molten iron after desulfurization is 0.005 wt% containing the S amount by mass percentage;
2) converter smelting: pretreated molten iron is imported to 100/120 ton of top and bottom combined blown converter, must guarantee in the stove molten iron to be that 0.005 wt%, P content are 0.080 wt% containing the S amount by mass percentage, molten iron temperature is 1270 ℃, press ± 1t of molten iron Intake Quantity error controls, steel scrap strictly adopts the high-quality scrap stock, slag making basicity R controlling valu is 2.5, and carbon content 0.035 wt% by mass percentage in the molten steel of coming out of the stove is 0.012 wt%, is 0.010 wt% containing the S mass percent containing the P mass percent; It is 2 times that point blows number of times, to avoid slag under tapping process;
3) LF stove refining: the molten iron of converter smelting is poured in the LF refining furnace, in refining process, must be carried out omnidistance Argon, add the basicity of refining slag by 4.0 controls; The refinement and deoxidation agent be take calcium carbide, aluminum shot, ferrosilicon powder as main, refining heat-processed selects suitable electric current to be heated according to rhythm is more than needed with temperature conditions, heat-up time is by twice control, heat for the first time 7min, heat for the second time 6min, require in heat-processed for the second time to add reductor according to the slag making situation; Dry slag 6 times, add silicon-calcium wire before leaving from station, must close argon gas before adding silicon-calcium wire; Upper steel Wen Wendu is 1610 ± 15 ℃;
4) Fruit storage: VD vacuum tightness is 67Pa, dwell time is 15min, wraps Bottom Argon Stirring simultaneously, soft blow 2min after vacuum breaker, in the soft blow process, molten steel must not be exposed, and normal online bag pumpdown time (vacuumizing front liquid steel temperature-target temperature leaving from station) is controlled at 1.7min; Then add insulating covering agent, guarantee to be paved with the molten steel face, must close argon gas before adding insulating covering agent, it is 1565 ± 15 ℃ that upper steel temperature is controlled;
5) continuous casting: before watering steel, guarantee that the casting machine status of equipment is good, the molten steel that refining is good injects tundish by large bag, the superheating temperature of tundish preheating is controlled at 15 ± 10 ℃, the control pulling rate of withdrawal straightening machine is 0.7m/min, the specific water is controlled at 0.80L/ ㎏, and in induction stirring, the electromagnetic control parameter is: 900A, 5Hz, 30s-3-30s; Continuous-casting steel pouring requires omnidistance argon shield casting, unwraps greatly to water in rear 1min and must overlap protective tube, guarantees not show of molten steel face in the basket pouring process; Rationally control stopper Argon amount in steel pouring process, guarantee that liquid level fluctuation of crystallizer is slight; The strand laggard windrow that rolls off the production line is cold, and the cooling in heap temperature is 200 ℃, and the cooling in heap time is 12h;
6) heating: strand is sent in pusher-type furnace and heated, press zone heating: 900 ℃ of preheating section temperature, 1200 ℃ of heating zone temperature, 1180 ℃ of holding-zone temperature, rate of heating is controlled at 8min/cm;
7) rolling: the strand of heating is delivered on the 3800mm milling train and is rolled, in the operation of rolling, for preventing mixed crystal and coarse grains, to strictly adhere to the rolling requirement of " high temperature, low speed, depress greatly ", start rolling temperature is 1100 ℃, the one-phase finishing temperature is 950 ℃, treats that temperature thickness is 2 times of finished product thickness; The two-stage start rolling temperature is 900 ℃, two-stage single pass draft is 15%, the accumulative total draft is 65%, guaranteed that distortion infiltration makes the elongation that is crushed of the inner crystal grain of austenite, increase the crystal boundary useful area and effectively form a large amount of deformation bands, for austenite phase transformation provides more forming core point, reached the purpose of refine austenite crystal grain, finishing temperature is controlled at 760 ℃;
8) the ACC laminar flow is cooling: according to the difference of thickness of slab, roll the different laminar flow of rear employing cooling, by adjusting cooling manifold group number, controlling speed of cooling is 5 ℃/S, red temperature is 450 ℃, is sent to the straightener aligning after laminar flow is cooling, and stacking slow cooling in time rolls off the production line after steel plates straightening, the cooling in heap temperature is 200 ℃, and the cooling in heap time is 24h.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011101784703A CN102433498B (en) | 2011-06-29 | 2011-06-29 | Q550 D high-quality structural iron medium and heavy plate and production method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011101784703A CN102433498B (en) | 2011-06-29 | 2011-06-29 | Q550 D high-quality structural iron medium and heavy plate and production method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102433498A CN102433498A (en) | 2012-05-02 |
| CN102433498B true CN102433498B (en) | 2013-11-20 |
Family
ID=45981844
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011101784703A Active CN102433498B (en) | 2011-06-29 | 2011-06-29 | Q550 D high-quality structural iron medium and heavy plate and production method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102433498B (en) |
Families Citing this family (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102899557B (en) * | 2012-11-02 | 2014-12-03 | 湖南华菱湘潭钢铁有限公司 | Production method of low-alloy medium plate |
| CN103014522A (en) * | 2012-12-30 | 2013-04-03 | 南阳汉冶特钢有限公司 | Novel low-cost wear-resistant high-strength Q550D steel plate and production method thereof |
| CN103243270A (en) * | 2012-12-30 | 2013-08-14 | 南阳汉冶特钢有限公司 | Novel low-cost, wear-resistant and high-strength Q460B steel plate and production method thereof |
| CN103556074B (en) * | 2013-11-12 | 2015-04-15 | 湖南华菱湘潭钢铁有限公司 | Production method of hardened and tempered high-strength Q500E super-thick steel plate |
| CN104561785A (en) * | 2014-12-31 | 2015-04-29 | 南阳汉冶特钢有限公司 | High-strength low-alloy structure A633GrD steel plate and production method thereof |
| CN105624383B (en) * | 2016-01-04 | 2017-09-15 | 河北钢铁股份有限公司邯郸分公司 | A kind of production method for improving high-strength cut deal product surface quality |
| CN105648329A (en) * | 2016-03-09 | 2016-06-08 | 山东钢铁股份有限公司 | Control rolling and high strength ship-plate steel and producing method thereof |
| CN107641767A (en) * | 2017-08-15 | 2018-01-30 | 河钢股份有限公司邯郸分公司 | A kind of low yield strength ratio Steels for High Rise Buildings Q550GJD and its production method |
| CN109500084B (en) * | 2018-12-06 | 2020-06-23 | 南阳汉冶特钢有限公司 | Production method of novel medium-thickness steel plate |
| CN110408847A (en) * | 2019-08-30 | 2019-11-05 | 南阳汉冶特钢有限公司 | A kind of high intensity ultralow temperature low-carbon bainite Q550MF steel plate and its production method |
| CN112322994A (en) * | 2020-11-04 | 2021-02-05 | 南阳汉冶特钢有限公司 | Method for producing low-cost Q355B medium plate through medium plate alloy leftover material |
| CN113604737B (en) * | 2021-07-30 | 2022-07-12 | 山东钢铁股份有限公司 | Q550D high-strength steel plate and preparation method thereof |
| CN114000035A (en) * | 2021-11-04 | 2022-02-01 | 南阳汉冶特钢有限公司 | Production method of atmospheric corrosion resistant high-strength extra-thick Q390GNH steel plate |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102051522A (en) * | 2010-12-21 | 2011-05-11 | 南阳汉冶特钢有限公司 | Steel plate made of bainite structure high-strength toughness structural steel Q550D(E) and production method thereof |
| CN102061351A (en) * | 2010-12-21 | 2011-05-18 | 南阳汉冶特钢有限公司 | Method for producing low-carbon steel and ultra-low-carbon steel by VD, LF and VD processes |
| CN102345061A (en) * | 2011-06-28 | 2012-02-08 | 南阳汉冶特钢有限公司 | Q690D quality structural medium steel plate and production method thereof |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5292784B2 (en) * | 2006-11-30 | 2013-09-18 | 新日鐵住金株式会社 | Welded steel pipe for high-strength line pipe excellent in low temperature toughness and method for producing the same |
| JP5181639B2 (en) * | 2006-12-04 | 2013-04-10 | 新日鐵住金株式会社 | Welded steel pipe for high-strength thick-walled line pipe excellent in low-temperature toughness and manufacturing method |
| CN101906568B (en) * | 2010-08-12 | 2011-12-07 | 中国石油天然气集团公司 | High-grade large-strain pipeline steel and manufacturing method of steel pipe |
-
2011
- 2011-06-29 CN CN2011101784703A patent/CN102433498B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102051522A (en) * | 2010-12-21 | 2011-05-11 | 南阳汉冶特钢有限公司 | Steel plate made of bainite structure high-strength toughness structural steel Q550D(E) and production method thereof |
| CN102061351A (en) * | 2010-12-21 | 2011-05-18 | 南阳汉冶特钢有限公司 | Method for producing low-carbon steel and ultra-low-carbon steel by VD, LF and VD processes |
| CN102345061A (en) * | 2011-06-28 | 2012-02-08 | 南阳汉冶特钢有限公司 | Q690D quality structural medium steel plate and production method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102433498A (en) | 2012-05-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102433498B (en) | Q550 D high-quality structural iron medium and heavy plate and production method thereof | |
| CN102345061B (en) | Q690D quality structural medium steel plate and production method thereof | |
| CN102418036B (en) | 15MnNiDR low alloy steel plate for low temperature pressure vessel and production method thereof | |
| CN102345057B (en) | High strength and toughness Q460E structural steel thick plate and production method thereof | |
| CN102409238B (en) | 42CrMo alloy constructional steel super-thick plate and production method thereof | |
| CN101880824B (en) | Q345q-series super-thick bridge steel plate and production method thereof | |
| CN105925894B (en) | A kind of high-strength anti-lamellar tearing Q500D Z35 Hydropower Units steel plates of super thick and its manufacture method | |
| CN102732789B (en) | High-performance ocean platform steel and its production method | |
| CN102080181B (en) | Low-alloy Q345D thick plate produced without adding micro-alloy elements and production method thereof | |
| CN103225047B (en) | The X80 pipeline steel of thickness >=26.5mm and production method thereof | |
| CN103866204B (en) | The large sstrain X80 dual phase sheet steel that the large soft reduction process of a kind of low temperature is produced | |
| CN101654760B (en) | Unalloyed structural steel S355J2 steel plate and production method thereof | |
| CN102899556A (en) | Production method for low-alloy medium-thick steel plate | |
| CN108070779A (en) | A kind of solderable fine grain, high strength degree structural steel and iron and its production method | |
| CN102345053A (en) | Hot-rolled structural steel ST52 medium-thick plate with thickness of 15-60mm and production method thereof | |
| CN105177420A (en) | S275NL high-tenacity and fine-grain structure steel plate and preparation method thereof | |
| CN103045966B (en) | High-quality and high-yield strength structural steel S620QL1 steel plate and production method thereof | |
| CN102703812A (en) | Titanium microalloyed 500-MPa high-strength steel bar and production method thereof | |
| CN102345055A (en) | Weldable fine grain structural steel S355NL/S355NLZ35 steel plate and its production method | |
| CN104561783A (en) | Low alloy steel 09MnNiDR steel plate for vessel and production method thereof | |
| CN102181794B (en) | Hardening and tempering high-strength steel plate for wood based panel equipment and production method of tempering high-strength steel plate | |
| CN103710620B (en) | A kind of heavy thickness steel plate for low temperature pressure container and production technique thereof | |
| CN103160746A (en) | High strength steel for thick wall water pipe and manufacturing method thereof | |
| CN102367544A (en) | High strength and toughness structural steel S355K2Z35 slab and production method thereof | |
| CN103160728B (en) | High-yield-strength S890QL structural steel medium plate 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 |