CN103276287B - A kind of high drawability flux-cored wire cold-rolled steel strip and manufacture method thereof - Google Patents
A kind of high drawability flux-cored wire cold-rolled steel strip and manufacture method thereof Download PDFInfo
- Publication number
- CN103276287B CN103276287B CN201310227691.4A CN201310227691A CN103276287B CN 103276287 B CN103276287 B CN 103276287B CN 201310227691 A CN201310227691 A CN 201310227691A CN 103276287 B CN103276287 B CN 103276287B
- Authority
- CN
- China
- Prior art keywords
- flux
- cored wire
- cold
- steel strip
- rolled steel
- 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.)
- Expired - Fee Related
Links
Landscapes
- Treatment Of Steel In Its Molten State (AREA)
- Heat Treatment Of Steel (AREA)
Abstract
The invention belongs to the technical field of flux-cored wire cold-rolled steel strip and production thereof, be specifically related to a kind of high drawability flux-cored wire cold-rolled steel strip and manufacture method thereof.This kind high drawability flux-cored wire cold-rolled steel strip, comprises the component of following weight percent: C≤0.0035%, Si≤0.03%, Mn 0.10 ~ 0.25%, P≤0.008%, S≤0.005%, N≤0.005%, Alt 0.02 ~ 0.04%, surplus is Fe and other inevitable impurity.The manufacture method of described high drawability flux-cored wire cold-rolled steel strip, comprises the following steps: (1) makes steel; (2) continuous casting; (3) hot rolling; (4) batch; (5) cold rolling; (6) anneal; (7) smooth.This kind high drawability flux-cored wire cold-rolled steel strip and manufacture method thereof, reduce the content of C, Si, P, S, improves the drawability of flux-cored wire cold-rolled steel strip, improves the performance of wlding heat affected zone; Suitable Mn content controls, and both ensure that flux-cored wire cold-rolled steel strip led to the stability of volume, finished product flux-cored wire has again enough bullet high level.
Description
Technical field
The invention belongs to the technical field of flux-cored wire cold-rolled steel strip and production thereof, be specifically related to a kind of high drawability flux-cored wire cold-rolled steel strip and manufacture method thereof.
Background technology
So far, the development of flux-cored wire mainly experienced by three phases, the flux-cored wire diameter of initial production is ￠ 3.2mm, ￠ 2.4mm, developing into diameter is afterwards ￠ 1.2 ~ 1.6mm, at present gradually by diameter ￠ 0.8mm ~ 1.4mm substitute, so to the high drawability of cold-rolled steel strip and logical roll stabilizing performance requriements more and more higher, simultaneously, flux-cored wire, in superstrength application in rings territory such as ocean platform, pressurized vessel, Cemented filling, it is also proposed higher requirement to the smelting composition of flux-cored wire cold-rolled steel strip.Traditional flux-cored wire cold-rolled steel strip seriously constrains development and the application of flux-cored wire, high drawability flux-cored wire cold-rolled steel strip refers to C≤0.005%, P≤0.008%, low yield strength 170 ~ 200MPa, low yield strength ratio 0.63, the cold-rolled steel strip of high-elongation >=43% and hardness HRB40 ~ 45, meets high drawability requirement when producing flux-cored wire completely.
Domesticly so far declare multinomial patent with regard to flux-cored wire cold-rolled steel strip and production technology method thereof.Such as, the patent of publication number CN102755992A, a kind of flux-cored wire cold-rolled steel strip production method, this steel grade designs according to Ultra-low carbon 0.01 ~ 0.025%, but phosphorus content≤0.015% is higher, have impact on the application of flux-cored wire in high-end field, and annealing employing is continuous annealing process, steel band yield strength, tensile strength are higher, and unit elongation is on the low side, and the flux-cored wire being difficult to adapt to diameter ￠ 0.8mm ~ 1.2mm is produced.
Such as, the patent of publication number CN102676917A, a kind of preparation method of flux-cored wire cold rolled sheet, this steel grade designs according to low-carbon (LC) 0.005 ~ 0.045%, have impact on the application of flux-cored wire in high-end field, and annealing employing is continuous annealing process, steel band yield strength, tensile strength are higher, unit elongation is on the low side, and the flux-cored wire being difficult to meet diameter ￠ 0.8mm ~ 1.2mm is produced.
Such as, the patent of publication number CN102021295B, for cold-rolled steel strip and the manufacture method thereof of flux-cored wire, this steel grade designs according to low-carbon (LC) C0.010 ~ 0.03%, although be adopt bell type annealing furnace to produce, but composition does not reach the requirement of ultra low-carbon steel, limit the application of flux-cored wire in high-end field.
Summary of the invention
The object of the invention is to the defect for above-mentioned existence and a kind of high drawability flux-cored wire cold-rolled steel strip and manufacture method thereof are provided, reduce the content of C, Si, P, S, improve the drawability of flux-cored wire cold-rolled steel strip, improve the performance of wlding heat affected zone; Suitable Mn content controls, and both ensure that flux-cored wire cold-rolled steel strip led to the stability of volume, ensures that again finished product flux-cored wire has enough bullet high level.
Technical scheme of the present invention is: a kind of high drawability flux-cored wire cold-rolled steel strip, described cold-rolled steel strip comprises the component of following weight percent: C≤0.0035%, Si≤0.03%, Mn 0.10 ~ 0.25%, P≤0.008%, S≤0.005%, N≤0.005%, Alt 0.02 ~ 0.04%, surplus is Fe and other inevitable impurity.
Described cold-rolled steel strip comprises the component of following weight percent: C 0.0025 ~ 0.0035%, Si 0.009 ~ 0.01%, Mn 0.15 ~ 0.20%, P 0.005 ~ 0.007%, S 0.0008 ~ 0.003%, N 0.0025 ~ 0.004%, Alt0.025 ~ 0.032%, surplus is Fe and other inevitable impurity.
The manufacture method of described high drawability flux-cored wire cold-rolled steel strip, comprises the following steps:
(1) make steel: the deeply de-S of a. molten iron: the front slag first removing molten iron, then under 1300 ~ 1380 DEG C of conditions, molten iron is carried out
KR pre-treatment, according to the Standard entertion sweetening agent of 7 kilograms of sweetening agent/1 ton molten iron, stirs, rotating speed
Be 85 ~ 95r/min, stir after within 12 minutes, completing, remove rear slag, make S≤0.005% in molten iron;
B. top and bottom combined blown converter double slag process takes off P and pre-de-C: add at the initial stage of blowing slag charge, oxygen blast 7 ~ 10 points in batches
Pre-slag outwelled by clock, then carries out the slag making again of oxygen blast catch carbon, and the slagging of falling stove i.e. secondary falls stove, makes converter eventually
Point C≤0.04%, P≤0.008%; Terminal tapping temperature is 1640 ~ 1650 DEG C; Press in tapping process
The weight percent of Mn 0.10 ~ 0.25% adds in molten iron;
C. LF refining: the molten iron of de-P is carried out LF refining, and adjustment makes Si≤0.03%, Mn
0.10~0.25%，N ≤0.005%，Alt 0.02~0.04%；
D. vacuum cycle takes off C: under 1630 ~ 1635 DEG C of conditions, send into RH through the molten iron of LF refining and carry out vacuum
The de-C of circulation, the oxygen blast when vacuum tightness reaches 250mbar, then determines oxygen and makes oxygen level 400 ~ 500ppm; Vacuum takes off 20 ~ 25 minutes C time, and with reference to exhaust-gas analyzer CO curve, CO is less than 0.3% maintenance more than 2 minutes i.e. de-C to be terminated; De-C terminates rear free oxygen and controls at 250 ~ 350ppm;
E. degasification technique: add aluminum shot in gained molten steel after vacuum cycle takes off C, controls the weight that aluminum shot accounts for molten steel
Per-cent is 0.04 ~ 0.05%, vacuum deaeration 29 ~ 34 minutes; Then blowing argon gas stirs 2 ~ 3 minutes,
Feed pure calcium line 150 ~ 200m, linear speed 150m/min, finally stirs, soft blow 10 ~ 15 minutes;
(2) continuous casting: adopt thin plate ASP casting machine double roller continuous casting, whole process protective casting, argon flow amount 150 ~ 180NL/min in protective casing;
(3) hot rolling: adopt ASP medium thin slab continuous casting and rolling, it is 1230 ~ 1270 DEG C that steel billet reheats temperature, roughing start rolling temperature
Be 1140 ~ 1180 DEG C, finish rolling start rolling temperature is 1030 ~ 1070 DEG C, finish rolling finishing temperature is 890 ~
930℃；
(4) batch: first carry out section cooling, speed of cooling is 25 ~ 30 DEG C/s, then carries out curling, coiling temperature is 570 ~
610℃；
(5) cold rolling: to adopt continuous shallow slot turbulence acid dip, acid strength is 120 ~ 200g/L, and pickling temperature is 70 ~ 90 DEG C, acid
Wash speed not higher than 140m/min; Cold rolling total reduction is 70 ~ 80%, and cold-rolling emulsion mass concentration is
2.5 ~ 5.0%, emulsion temperature is 50 ~ 60 DEG C;
(6) anneal: annealing hot(test)-spot temperature is 715 ~ 735 DEG C, and cold-point temperature is 680 ~ 700 DEG C, and soaking time is 13 ~ 15 little
Time, band cover cooling temperature is 570 ~ 590 DEG C;
(7) smooth: smooth unit elongation is 0.8 ~ 1.3%.
Sweetening agent in the deeply de-S of described step a. molten iron adds when rotating speed is 60r/min.
In described step (2) casting process, cooling twice adopts cold by force, and liquid level fluctuation of crystallizer controls within ± 3mm.
The hot-rolled finished product thickness of described step (3) hot rolling is 4.0mm.
Described step (6) annealing adopts Ai Baina full-hydrogen hood-type annealing furnace.
Described step (7) smooth employing four roller single chassis.
beneficial effect of the present invention is: in involved flux-cored wire cold-rolled steel strip, the effect of chemical composition is as follows: C: high C content can cause the cementite rank of cold rolling rear product to raise, harder and crisp cementite hinders ferrite base body deformability, orientation texture density perpendicular to steel plate normal direction is reduced, the timeliness problem of steel is obvious, intensity increases, plasticity declines, and namely unit elongation, n value and r value all reduce; Meanwhile, along with the increase of C content, plasticity, the toughness of weld metal decline.Therefore the present invention adopts the Ultra-low carbon of C≤0.0035% to design.
Si: the deoxidizing capacity of silicon is stronger than Mn is main reductive agent and reductor, can eliminate FeO and be mingled with detrimentally affect to steel; Si is present in steel with solution, can improve intensity and the hardness of steel.But along with the content of silicon increases, the iron scale (steel band is formed when hot rolling) of steel strip surface is difficult to remove, and make the surface quality of steel band degenerate, therefore the present invention designs Si content≤0.03%.
Mn: have good deoxidizing capacity, can remove the FeO in steel, can also form MnS with S, to eliminate the deleterious effect of S; In steel, part and iron dissolve each other formation sosoloid, have obvious effect to raising intensity; The Mn be solid-solution in deep drawing steel annealing process in ferrite hinders the growth of the orientation crystal grain of preferential forming core, and the intensity of material increases, and plasticity declines, and r value reduces, and should reduce its content as far as possible.The present invention designs Mn content 0.10 ~ 0.25%, namely ensure that the forming property of steel, in turn ensure that the intensity of steel.
P: for deep drawing steel, along with the increase of P content, yield strength, tensile strength increase, and n value, r value and unit elongation reduce.P has serious segregation tendency in crystallisation process, thus is locally occurring cold short, and make steel occur banded structure after hot rolling, and the velocity of diffusion of P in γ-Fe and α-Fe is very little, is difficult to the segregation eliminating P with heat treating method.Therefore the present invention designs P content≤0.008%.
S: forming sulfide inclusion (mainly MnS) in steel, is harmful element is particularly serious to the deep-draw steel of machining deformation complexity.In the operation of rolling along rolling direction into strips or chainlike distribution, thus make the transverse cold bending performance depreciation of steel plate, produce anisotropy.In addition, S also can cause the red brittleness of steel plate.When the content of sulphur is lower in steel, the content of manganese in steel can be reduced, so the content of element sulphur reduces as much as possible in steel.Therefore the present invention designs S content≤0.005%.
Al: generally add as reductor, the oxygen in molten steel is mainly removed in effect, Al suppresses the solid solution of nitrogen in ferrite as determining nitrogen agent in addition, aluminium mainly controls the tissue of finished steel plate and the position of interstitial atom with the form of second-phase AlN, thus improve steel plate punched performance, eliminate strain aging, improve cold plasticity and prevent from producing slip line in punching course.The present invention designs Alt content 0.02 ~ 0.04%.
Present invention also offers the manufacture method of high drawability flux-cored wire cold-rolled steel strip: steel-making adopts the deeply de-S of molten iron, top and bottom combined blown converter double slag dephosphorization, and RH vacuum cycle takes off C, degasification technique, whole process protective casting; Hot rolling adopts ASP medium thin slab continuous casting and rolling technology, and finish rolling finishing temperature is 890 ~ 930 DEG C, and coiling temperature is 570 ~ 610 DEG C; Cold rolling employing double stand reversing milling train, cold rolling total reduction is 70 ~ 80%, full-hydrogen hood-type annealing furnace hot(test)-spot temperature 715 ~ 735 DEG C, the permanent unit elongation pattern of smooth employing.
In sum: 1. flux-cored wire cold-rolled steel strip provided by the invention, its low C, low P, low S composition, improve the drawability of flux-cored wire cold-rolled steel strip, improve the performance of wlding heat affected zone, suitable Mn content controls, both ensure that flux-cored wire cold-rolled steel strip led to the stability of volume, finished product flux-cored wire also obtain enough bullet high level.
2. flux-cored wire cold-rolled steel strip provided by the invention, its low yield strength 170 ~ 200MPa, low yield strength ratio, high-elongation >=43% and moderate surface hardness HRB40 ~ 45, meet high drawability requirement when producing flux-cored wire.
3. the production technique of steel of the present invention is that steel-making adopts top and bottom combined blown converter double slag dephosphorization, P content≤0.008%; Hot rolling adopts the temperature schedule of " three high and one low ", promotes to form favorable texture; Cold rolling employing heavy reduction rate rolling, high temperature annealing and permanent unit elongation are smooth, both ensure that cold-rolled steel strip perfect recrystallization, in turn ensure that the stable of logical volume performance.
Accompanying drawing explanation
Fig. 1 is the permanent 45 ° of cross section texture patterns of ODF of embodiment 1 flux-cored wire cold-rolled steel strip.
Fig. 2 is the permanent 45 ° of cross section texture patterns of ODF of embodiment 2 flux-cored wire cold-rolled steel strip.
Fig. 3 is the representative microstructure pattern of embodiment 1 flux-cored wire cold-rolled steel strip.
Fig. 4 is the representative microstructure pattern of embodiment 2 flux-cored wire cold-rolled steel strip.
Embodiment
Below by specific embodiment, the present invention is described in detail.
Embodiment 1
High drawability flux-cored wire cold-rolled steel strip comprises the component of following weight percent: C 0.003%, Si 0.01%, Mn 0.15%, P 0.006%, S 0.003%, N 0.0025%, Alt (dissolved aluminum) 0.032%, surplus is Fe and other inevitable impurity.
The manufacture method of described high drawability flux-cored wire cold-rolled steel strip, comprises the following steps:
(1) make steel: the deeply de-S of a. molten iron: first to skim requirement and liquid level is exposed is greater than 3/4 according to one-level, remove the front slag of molten iron, then under 1300 ~ 1380 DEG C of conditions, KR pre-treatment is carried out to molten iron, when rotating speed is 60r/min, according to the Standard entertion sweetening agent of 7 kilograms of sweetening agent/1 ton molten iron, stir, rotating speed is 85 ~ 95r/min, stir after within 12 minutes, completing, remove rear slag, make S content in molten iron be 0.003%;
B. top and bottom combined blown converter double slag process takes off P and pre-de-C: adopt low-phosphorous low-sulfur high-quality steel scrap, the molten iron P content entering stove is less than 0.090%, blowing initial stage slag charge several times short run adds, oxygen blast within 7 ~ 10 minutes, outwell pre-slag namely once fall stove, carry out the slag making again of oxygen blast catch carbon again, the slagging of falling stove i.e. secondary falls stove, and the tap hole life-span is less than 100 stoves, realize two pushing off the slag operation, stop slag of tapping; Make converter terminal C≤0.04%, P content is 0.006%; Terminal tapping temperature is 1640 ~ 1650 DEG C; Add in molten iron by the weight percent of Mn 0.10 ~ 0.25% in tapping process;
C. LF refining: the molten iron of de-P is carried out LF refining, and adjustment makes Si 0.01%, Mn 0.15%, N 0.0025%, Alt 0.032%;
D. vacuum cycle takes off C: under 1630 ~ 1635 DEG C of conditions, send into RH through the molten iron of LF refining and carry out vacuum cycle and take off C, carbon dust can not be stayed in C storehouse, and haul belt can not have residual carbon dust, and ensures that aluminum shot is pure.First use preliminary vacuum tupe, then be evacuated to final vacuum and be low vacuum in 2mPa.Carry out oxygen blast according to temperature, free oxygen, aluminium content and C content, the oxygen blast when vacuum tightness reaches 250mbar, then determine oxygen and make oxygen level 400 ~ 500ppm; Should re-blow immediately according to oxygen level situation if oxygen level is less than 400ppm, control top gun gun bit and oxygen blast flow well.Vacuum takes off 20 ~ 25 minutes C time, and with reference to exhaust-gas analyzer CO curve, CO is less than 0.3% maintenance more than 2 minutes i.e. de-C to be terminated; De-C terminates rear free oxygen and controls at 250 ~ 350ppm;
E. degasification technique: add aluminum shot in gained molten steel after vacuum cycle takes off C, the weight percent that control aluminum shot accounts for molten steel is 0.04 ~ 0.05%, vacuum deaeration 29 ~ 34 minutes; After deoxidation, add appropriate aluminum shot slag making (normal circumstances 40 ~ 60kg) on slag surface, if bits crust, add again after sky can be broken.Treat that ladle falls after broken sky and open argon bottom-blowing immediately from soaking tub, atm number stirs 2 ~ 3min, be advisable with not coil slag, but must slag be changed, then suitably turn argon gas down, feed pure calcium line 150 ~ 200m, linear speed 150m/min, carry out weak stirring after line feeding, avoid bits to crust as far as possible, 10 ~ 15 minutes soft blow time.
(2) continuous casting: adopt thin plate ASP casting machine double roller continuous casting, whole process protective casting, argon flow amount 150 ~ 180NL/min in protective casing.Continuous casting adopts Ultra-low carbon covering slag; Ladle protective casting, increases N amount≤5ppm; Stop air-breathing between middle wrapper sheet, suitably open argon shield; Adopt thin plate ASP casting machine, require suitably to control pulling rate according to section; Cooling twice adopts cold by force, and liquid level fluctuation of crystallizer controls within ± 3mm.
(3) hot rolling: hot rolling adopts ASP medium thin slab continuous casting and rolling technology, equipment mainly comprises: three walking beam heating furnaces, four roller reversible roughing mills of edger roll before a band, stay-warm case, crop flying shear, six frame finishing train, cooling facility for laminar flow, three equipment such as reeling machine and a set of coil of strip conveying system compositions.Adopt direct hot charging, hydraulic AGC, Hydraulic Looper, roller, string roller arrangement, make steel band obtain good template and thickness control accuracy.Steel billet reheats temperature 1250 DEG C, roughing start rolling temperature 1170 DEG C, finish rolling start rolling temperature 1060 DEG C, finish rolling finishing temperature 920 DEG C.
(4) batch: section cooling employing multistage is thick, accurate adjustment valve group, cooling section control techniques, make each cooling section water yield and stable water pressure, steel band longitudinal temperature is even, and is furnished with side spray function, prevent the inhomogeneous cooling of steel band even, blow down with the pressure water of 1MPa the water coolant be trapped in steel strip surface.Section cooling speed is 26 DEG C/s, the sparse cooling of back segment, reeling machine adopts the automatic Autostep technology of Wrapping Roll of the side guide of hydrostatic control, pinch roll, Wrapping Roll, stepless expanding-contracting type reel and high response speed, realize steel band precise alignment, Minimal Tension batches, reduce turriform, steel band head and Wrapping Roll can be eliminated to the impression of steel band simultaneously; Coiling temperature 580 DEG C.
(5) cold rolling: to adopt continuous shallow slot turbulence acid dip, acid strength is 120 ~ 200g/L, and pickling temperature is 70 ~ 90 DEG C, and pickling speed is not higher than 140m/min; Cold rolling total reduction is 75%, and cold-rolling emulsion mass concentration is 2.5 ~ 5.0%, and emulsion temperature is 50 ~ 60 DEG C;
(6) anneal: annealing adopts Ai Baina import full-hydrogen hood-type annealing furnace, annealing hot(test)-spot temperature is 725 DEG C, and cold-point temperature is 690 DEG C, and soaking time is 13.5 hours, and band cover cooling temperature is 550 DEG C;
(7) smooth: smooth employing four roller single chassis permanent unit elongation, wet jetting piles pattern, smooth unit elongation 1.0%.
The mechanical property of the present embodiment hot continuous rolling steel is yield strength is 255MPa, and tensile strength is 320MPa, and yield tensile ratio is 0.80, unit elongation A
50be 44%, grain fineness number level is 8.
The mechanical property of the present embodiment cold-rolled steel is yield strength is 180MPa, and tensile strength is 295MPa, and yield tensile ratio is 0.61, unit elongation A
80be 45%, grain fineness number level is 7.5, n value be 0.23, r value be 2.5, surface hardness HRB is 42.
Embodiment 2
High drawability flux-cored wire cold-rolled steel strip comprises the component of following weight percent: C0.0025%, Si 0.01%,
Mn 0.20%, P 0.005%, S0.002%, N 0.0030%, Alt 0.03%, surplus is Fe and other inevitable impurity.
The manufacture method of described high drawability flux-cored wire cold-rolled steel strip, comprises the following steps:
(1) make steel: the deeply de-S of a. molten iron: first to skim requirement and liquid level is exposed is greater than 3/4 and removes slag before molten iron according to one-level, then under 1300 ~ 1380 DEG C of conditions, KR pre-treatment is carried out to molten iron, when rotating speed is 60r/min, according to the Standard entertion sweetening agent of 7 kilograms of sweetening agent/1 ton iron, stir, rotating speed is 85 ~ 95r/min, stirs after within 12 minutes, completing, remove rear slag, make S content in molten iron be 0.002%;
B. top and bottom combined blown converter double slag process takes off P and pre-de-C: adopt low-phosphorous low-sulfur high-quality steel scrap, the molten iron P content entering stove is less than 0.090%, blowing initial stage slag charge several times short run adds, oxygen blast within 7 ~ 10 minutes, outwell pre-slag namely once fall stove, carry out the slag making again of oxygen blast catch carbon again, the slagging of falling stove i.e. secondary falls stove, and the tap hole life-span is less than 100 stoves, realize two pushing off the slag operation, stop slag of tapping; Make converter terminal C≤0.04%, P content is 0.005%; Terminal tapping temperature is 1640 ~ 1650 DEG C; Add in molten iron by the weight percent of Mn 0.10 ~ 0.25% in tapping process;
C. LF refining: the molten iron of de-P is carried out LF refining, and adjustment makes Si 0.01%, Mn 0.20%, N 0.0030%, Alt 0.03%;
D. vacuum cycle takes off C: under 1630 ~ 1635 DEG C of conditions, send into RH through the molten iron of LF refining and carry out vacuum cycle and take off C, carbon dust can not be stayed in C storehouse, and haul belt can not have residual carbon dust, and ensures that aluminum shot is pure.Adopt preliminary vacuum tupe, then be evacuated to final vacuum and be low vacuum in 2mPa.Carry out oxygen blast according to temperature, free oxygen, aluminium content and C content, the oxygen blast when vacuum tightness reaches 250mbar, then determine oxygen and make oxygen level 400 ~ 500ppm; Should re-blow immediately according to oxygen level situation if oxygen level is less than 400ppm, control top gun gun bit and oxygen blast flow well.Vacuum takes off 20 ~ 25 minutes C time, and with reference to exhaust-gas analyzer CO curve, CO is less than 0.3% maintenance more than 2 minutes i.e. de-C to be terminated; De-C terminates rear free oxygen and controls at 250 ~ 350ppm;
E. degasification technique: add aluminum shot in gained molten steel after vacuum cycle takes off C, controls aluminum shot and accounts for the weight percent of molten steel 0.04 ~ 0.05%, vacuum deaeration 29 ~ 34 minutes; After deoxidation, add appropriate aluminum shot slag making (normal circumstances 40 ~ 60kg) on slag surface, if bits crust, add again after sky can be broken.Treat that ladle falls after broken sky and open argon bottom-blowing immediately from soaking tub, atm number stirs 2 ~ 3min, be advisable with not coil slag, but must slag be changed, then suitably turn argon gas down, feed pure calcium line 150 ~ 200m, linear speed 150m/min, carry out weak stirring after line feeding, avoid bits to crust as far as possible, 10 ~ 15 minutes soft blow time.
(2) continuous casting: adopt thin plate ASP casting machine double roller continuous casting, whole process protective casting, argon flow amount 150 ~ 180NL/min in protective casing.Continuous casting adopts Ultra-low carbon covering slag; Ladle protective casting, increases N amount≤5ppm; Stop air-breathing between middle wrapper sheet, suitably open argon shield; Adopt thin plate ASP casting machine, require suitably to control pulling rate according to section; Cooling twice adopts cold by force, and liquid level fluctuation of crystallizer controls within ± 3mm.
(3) hot rolling: hot rolling adopts ASP medium thin slab continuous casting and rolling technology, equipment mainly comprises: three walking beam heating furnaces, four roller reversible roughing mills of edger roll before a band, stay-warm case, crop flying shear, six frame finishing train, cooling facility for laminar flow, three reeling machines and a set of coil of strip conveying system etc.Adopt direct hot charging, hydraulic AGC, Hydraulic Looper, roller, string roller arrangement, make steel band obtain good template and thickness control accuracy.Steel billet reheats temperature 1245 DEG C, roughing start rolling temperature 1170 DEG C, finish rolling start rolling temperature 1055 DEG C, finish rolling finishing temperature 915 DEG C.
(4) batch: section cooling employing multistage is thick, accurate adjustment valve group, cooling section control techniques, make each cooling section water yield and stable water pressure, steel band longitudinal temperature is even, and is furnished with side spray function, prevent the inhomogeneous cooling of steel band even, blow down with the pressure water of 1MPa the water coolant be trapped in steel strip surface.Section cooling speed is 25 DEG C/s, the sparse cooling of back segment, reeling machine adopts the automatic Autostep technology of Wrapping Roll of the side guide of hydrostatic control, pinch roll, Wrapping Roll, stepless expanding-contracting type reel and high response speed, realize steel band precise alignment, Minimal Tension batches, reduce turriform, steel band head and Wrapping Roll can be eliminated to the impression of steel band simultaneously; Coiling temperature 590 DEG C.
(5) cold rolling: to adopt continuous shallow slot turbulence acid dip, acid strength is 120 ~ 200g/L, and pickling temperature is 70 ~ 90 DEG C, and pickling speed is not higher than 140m/min; Cold rolling total reduction is 80%, and cold-rolling emulsion mass concentration is 2.5 ~ 5.0%, and emulsion temperature is 50 ~ 60 DEG C;
(6) anneal: annealing adopts Ai Baina import full-hydrogen hood-type annealing furnace, annealing hot(test)-spot temperature is 725 DEG C, and cold-point temperature is 690 DEG C, and soaking time is 13 hours, and band cover cooling temperature is 550 DEG C;
(7) smooth: smooth employing four roller single chassis permanent unit elongation, wet jetting piles pattern, smooth unit elongation 1.2%.
The mechanical property of the present embodiment hot continuous rolling steel is yield strength is 250MPa, and tensile strength is 315MPa, and yield tensile ratio is 0.79, unit elongation A
50be 45%, grain fineness number level is 8.5.
The mechanical property of the present embodiment cold-rolled steel is yield strength is 185MPa, and tensile strength is 293MPa, and yield tensile ratio is 0.63, unit elongation A
80be 46%, grain fineness number level is 7.5, n value be 0.24, r value be 2.6, surface hardness HRB is 41.
Embodiment 3
High drawability flux-cored wire cold-rolled steel strip comprises the component of following weight percent: C0.0035%, Si 0.009%,
Mn 0.15%, P 0.007%, S 0.0008%, N 0.0040%, Alt 0.025%, surplus is Fe and other inevitable impurity.
The manufacture method of described high drawability flux-cored wire cold-rolled steel strip, comprises the following steps:
(1) make steel: the deeply de-S of a. molten iron: first to skim requirement and liquid level is exposed is greater than 3/4 and removes slag before molten iron according to one-level, then under 1300 ~ 1380 DEG C of conditions, KR pre-treatment is carried out to molten iron, when rotating speed is 60r/min, according to the Standard entertion sweetening agent of 7 kilograms of sweetening agent/1 ton iron, stir, rotating speed is 85 ~ 95r/min, stirs after within 12 minutes, completing, remove rear slag, make S content in molten iron be 0.0008%;
B. top and bottom combined blown converter double slag process takes off P and pre-de-C: adopt low-phosphorous low-sulfur high-quality steel scrap, the molten iron P content entering stove is less than 0.090%, blowing initial stage slag charge several times short run adds, oxygen blast within 7 ~ 10 minutes, outwell pre-slag namely once fall stove, carry out the slag making again of oxygen blast catch carbon again, the slagging of falling stove i.e. secondary falls stove, and the tap hole life-span is less than 100 stoves, realize two pushing off the slag operation, stop slag of tapping; Make converter terminal C≤0.04%, P content is 0.007%; Terminal tapping temperature is 1640 ~ 1650 DEG C; Add in molten iron by the weight percent of Mn 0.10 ~ 0.25% in tapping process;
C. LF refining: the molten iron of de-P is carried out LF refining, and adjustment makes Si 0.009%, Mn 0.15%, N 0.0040%, Alt 0.025%;
D. vacuum cycle takes off C: under 1630 ~ 1635 DEG C of conditions, send into RH through the molten iron of LF refining and carry out vacuum cycle and take off C, carbon dust can not be stayed in C storehouse, and haul belt can not have residual carbon dust, and ensures that aluminum shot is pure.Adopt preliminary vacuum tupe, then be evacuated to final vacuum and be low vacuum in 2mPa.Carry out oxygen blast according to temperature, free oxygen, aluminium content and C content, the oxygen blast when vacuum tightness reaches 250mbar, then determine oxygen and make oxygen level 400 ~ 500ppm; Should re-blow immediately according to oxygen level situation if oxygen level is less than 400ppm, control top gun gun bit and oxygen blast flow well.Vacuum takes off 20 ~ 25 minutes C time, and with reference to exhaust-gas analyzer CO curve, CO is less than 0.3% maintenance more than 2 minutes i.e. de-C to be terminated; De-C terminates rear free oxygen and controls at 250 ~ 350ppm;
E. degasification technique: add aluminum shot in gained molten steel after vacuum cycle takes off C, control aluminum shot and account for the weight percent of molten steel 0.04 ~ 0.05%, vacuum deaeration is not less than 29 minutes; After deoxidation, add appropriate aluminum shot slag making (normal circumstances 40 ~ 60kg) on slag surface, if bits crust, add again after sky can be broken.Treat that ladle falls after broken sky and open argon bottom-blowing immediately from soaking tub, atm number stirs 2 ~ 3min, be advisable with not coil slag, but must slag be changed, then suitably turn argon gas down, feed pure calcium line 150 ~ 200m, linear speed 150m/min, carry out weak stirring after line feeding, avoid bits to crust as far as possible, 10 ~ 15 minutes soft blow time.
(2) continuous casting: adopt thin plate ASP casting machine double roller continuous casting, whole process protective casting, argon flow amount 150 ~ 180NL/min in protective casing.Continuous casting adopts Ultra-low carbon covering slag; Ladle protective casting, increases N amount≤5ppm; Stop air-breathing between middle wrapper sheet, suitably open argon shield; Adopt thin plate ASP casting machine, require suitably to control pulling rate according to section; Cooling twice adopts cold by force, and liquid level fluctuation of crystallizer controls within ± 3mm.
(3) hot rolling: hot rolling adopts ASP medium thin slab continuous casting and rolling technology, equipment mainly comprises: three walking beam heating furnaces, four roller reversible roughing mills of edger roll before a band, stay-warm case, crop flying shear, six frame finishing train, cooling facility for laminar flow, three reeling machines and a set of coil of strip conveying system etc.Adopt direct hot charging, hydraulic AGC, Hydraulic Looper, roller, string roller arrangement, make steel band obtain good template and thickness control accuracy.Steel billet reheats temperature 1260 DEG C, roughing start rolling temperature 1175 DEG C, finish rolling start rolling temperature 1060 DEG C, finish rolling finishing temperature 920 DEG C.
(4) batch: section cooling employing multistage is thick, accurate adjustment valve group, cooling section control techniques, make each cooling section water yield and stable water pressure, steel band longitudinal temperature is even, and is furnished with side spray function, prevent the inhomogeneous cooling of steel band even, blow down with the pressure water of 1MPa the water coolant be trapped in steel strip surface.Section cooling speed is 26 DEG C/s, the sparse cooling of back segment, reeling machine adopts the automatic Autostep technology of Wrapping Roll of the side guide of hydrostatic control, pinch roll, Wrapping Roll, stepless expanding-contracting type reel and high response speed, realize steel band precise alignment, Minimal Tension batches, reduce turriform, steel band head and Wrapping Roll can be eliminated to the impression of steel band simultaneously; Coiling temperature 585 DEG C.
(5) cold rolling: to adopt continuous shallow slot turbulence acid dip, acid strength is 120 ~ 200g/L, and pickling temperature is 70 ~ 90 DEG C, and pickling speed is not higher than 140m/min; Cold rolling total reduction is 77%, and cold-rolling emulsion mass concentration is 2.5 ~ 5.0%, and emulsion temperature is 50 ~ 60 DEG C;
(6) anneal: annealing adopts Ai Baina import full-hydrogen hood-type annealing furnace, annealing hot(test)-spot temperature is 725 DEG C, and cold-point temperature is 690 DEG C, and soaking time is 14 hours, and band cover cooling temperature is 550 DEG C;
(7) smooth: smooth employing four roller single chassis permanent unit elongation, wet jetting piles pattern, smooth unit elongation 0.9%.
The mechanical property of the present embodiment hot continuous rolling steel is yield strength is 260MPa, and tensile strength is 330MPa, and yield tensile ratio is 0.78, unit elongation A
50be 44%, grain fineness number level is 8.
The mechanical property of the present embodiment cold-rolled steel is yield strength is 190MPa, and tensile strength is 290MPa, and yield tensile ratio is 0.65, unit elongation A
80be 44%, grain fineness number level is 7.5, n value be 0.23, r value be 2.6, surface hardness HRB is 41.
Claims (5)
1. the manufacture method of one kind high drawability flux-cored wire cold-rolled steel strip, it is characterized in that, this high drawability flux-cored wire cold-rolled steel strip comprises the component of following weight percent: C≤0.0035%, Si≤0.03%, Mn 0.10 ~ 0.25%, P≤0.008%, S≤0.005%, N≤0.005%, Alt 0.02 ~ 0.04%, surplus is Fe and other inevitable impurity, comprises the following steps:
(1) make steel: the deeply de-S of a. molten iron: the front slag first removing molten iron, then under 1300 ~ 1380 DEG C of conditions, KR pre-treatment is carried out to molten iron, according to the Standard entertion sweetening agent of 7 kilograms of sweetening agent/1 ton molten iron, stir, rotating speed is 85 ~ 95r/min, stir after within 12 minutes, completing, remove rear slag, make S≤0.005% in molten iron;
B. top and bottom combined blown converter double slag process takes off P and pre-de-C: add at the initial stage of blowing slag charge, oxygen blast outwells pre-slag in 7 ~ 10 minutes in batches, then carries out the slag making again of oxygen blast catch carbon, and the slagging of falling stove i.e. secondary falls stove, makes converter terminal C≤0.04%, P≤0.008%; Terminal tapping temperature is 1640 ~ 1650 DEG C; Add in molten iron by the weight percent of Mn 0.10 ~ 0.25% in tapping process;
C. LF refining: the molten iron of de-P is carried out LF refining, and adjustment makes Si≤0.03%, Mn 0.10 ~ 0.25%, N≤0.005%, Alt 0.02 ~ 0.04%;
D. vacuum cycle takes off C: under 1630 ~ 1635 DEG C of conditions, send into RH through the molten iron of LF refining and carry out vacuum cycle and take off C, the oxygen blast when vacuum tightness reaches 250mbar, then determine oxygen and make oxygen level 400 ~ 500ppm; Vacuum takes off 20 ~ 25 minutes C time, and with reference to exhaust-gas analyzer CO curve, CO is less than 0.3% maintenance more than 2 minutes i.e. de-C to be terminated; De-C terminates rear free oxygen and controls at 250 ~ 350ppm;
E. degasification technique: add aluminum shot in gained molten steel after vacuum cycle takes off C, the weight percent that control aluminum shot accounts for molten steel is 0.04 ~ 0.05%, vacuum deaeration 29 ~ 34 minutes; Then blowing argon gas stirs 2 ~ 3 minutes, and feed pure calcium line 150 ~ 200m, linear speed 150m/min, finally stirs, soft blow 10 ~ 15 minutes;
(2) continuous casting: adopt thin plate ASP casting machine double roller continuous casting, whole process protective casting, argon flow amount 150 ~ 180NL/min in protective casing;
(3) hot rolling: adopt ASP medium thin slab continuous casting and rolling, it is 1230 ~ 1270 DEG C that steel billet reheats temperature, and roughing start rolling temperature is 1140 ~ 1180 DEG C, and finish rolling start rolling temperature is 1030 ~ 1070 DEG C, and finish rolling finishing temperature is 890 ~ 930 DEG C;
(4) batch: first carry out section cooling, speed of cooling is 25 ~ 30 DEG C/s, then carries out curling, and coiling temperature is 570 ~ 610 DEG C;
(5) cold rolling: to adopt continuous shallow slot turbulence acid dip, acid strength is 120 ~ 200g/L, and pickling temperature is 70 ~ 90 DEG C, and pickling speed is not higher than 140m/min; Cold rolling total reduction is 70 ~ 80%, and cold-rolling emulsion mass concentration is 2.5 ~ 5.0%, and emulsion temperature is 50 ~ 60 DEG C;
(6) anneal: annealing hot(test)-spot temperature is 715 ~ 735 DEG C, and cold-point temperature is 680 ~ 700 DEG C, and soaking time is 13 ~ 15 hours, band cover cooling temperature is 570 ~ 590 DEG C;
(7) smooth: smooth unit elongation is 0.8 ~ 1.3%.
2. the manufacture method of high drawability flux-cored wire cold-rolled steel strip according to claim 1, is characterized in that, the sweetening agent in the deeply de-S of described step a. molten iron adds when rotating speed is 60r/min.
3. the manufacture method of high drawability flux-cored wire cold-rolled steel strip according to claim 1, it is characterized in that, the hot-rolled finished product thickness of described step (3) hot rolling is 4.0mm.
4. the manufacture method of high drawability flux-cored wire cold-rolled steel strip according to claim 1, is characterized in that, described step (6) annealing adopts Ai Baina full-hydrogen hood-type annealing furnace.
5. the manufacture method of high drawability flux-cored wire cold-rolled steel strip according to claim 1, is characterized in that, described step (7) smooth employing four roller single chassis.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310227691.4A CN103276287B (en) | 2013-06-08 | 2013-06-08 | A kind of high drawability flux-cored wire cold-rolled steel strip and manufacture method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310227691.4A CN103276287B (en) | 2013-06-08 | 2013-06-08 | A kind of high drawability flux-cored wire cold-rolled steel strip and manufacture method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103276287A CN103276287A (en) | 2013-09-04 |
| CN103276287B true CN103276287B (en) | 2015-09-16 |
Family
ID=49058900
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310227691.4A Expired - Fee Related CN103276287B (en) | 2013-06-08 | 2013-06-08 | A kind of high drawability flux-cored wire cold-rolled steel strip and manufacture method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103276287B (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103741019B (en) * | 2013-12-19 | 2016-04-20 | 马钢(集团)控股有限公司 | A kind of hot rolled strip and production method thereof |
| CN104294015B (en) * | 2014-10-24 | 2016-08-24 | 山西太钢不锈钢股份有限公司 | The method for annealing of ER80S-1CM bonding wire steel |
| KR101795970B1 (en) * | 2016-10-11 | 2017-11-09 | 주식회사 포스코 | Cold-rolled steel sheet for flux cored wire and manufacturing the same |
| CN106498112B (en) * | 2016-10-26 | 2018-06-12 | 武汉钢铁有限公司 | A kind of method for smelting welding wire steel H08B |
| CN106756435B (en) * | 2016-12-23 | 2019-10-08 | 首钢集团有限公司 | A kind of smelting process of welding wire steel |
| CN106755731B (en) * | 2016-12-23 | 2019-01-18 | 首钢集团有限公司 | A kind of method of duplex technique production low-carbon welding wire steel |
| KR102134310B1 (en) * | 2017-12-26 | 2020-07-15 | 주식회사 포스코 | Cold-rolled steel sheet for flux cored wire and manufacturing the same |
| CN109440015A (en) * | 2018-11-12 | 2019-03-08 | 包头钢铁（集团）有限责任公司 | A kind of 400MPa grades of cold rolling sliding rail steel and its manufacturing method |
| CN111014603B (en) * | 2019-12-30 | 2022-02-25 | 江苏沙钢集团有限公司 | Double-roller casting-rolling production method of boron-added steel |
| CN112708827B (en) * | 2020-12-17 | 2022-06-21 | 包头钢铁（集团）有限责任公司 | Ultrathin steel strip for battery case and electronic basic element and manufacturing method thereof |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102416404A (en) * | 2011-09-21 | 2012-04-18 | 首钢总公司 | Method for producing cold-rolled steel strips |
| CN102755992A (en) * | 2012-07-30 | 2012-10-31 | 武汉钢铁(集团)公司 | Production method of cold-rolled steel strip for flux cored wire |
-
2013
- 2013-06-08 CN CN201310227691.4A patent/CN103276287B/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102416404A (en) * | 2011-09-21 | 2012-04-18 | 首钢总公司 | Method for producing cold-rolled steel strips |
| CN102755992A (en) * | 2012-07-30 | 2012-10-31 | 武汉钢铁(集团)公司 | Production method of cold-rolled steel strip for flux cored wire |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103276287A (en) | 2013-09-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103276287B (en) | A kind of high drawability flux-cored wire cold-rolled steel strip and manufacture method thereof | |
| CN109865742B (en) | Production method of thin hot-rolled pickled automobile plate with tensile strength of 440MPa | |
| CN101418363B (en) | Method for producing low carbon and high ductility X60/X65pipeline steel | |
| CN102899556B (en) | Production method for low-alloy medium-thick steel plate | |
| CN105274430B (en) | A kind of production method of the ultra-thin size hot-rolled Punching Steel of 510MPa grades of tensile strength 390 | |
| CN103924163A (en) | Austenite stainless steel and production method thereof | |
| CN112011737B (en) | 390 MPa-grade-20-DEG C-resistant hot-rolled angle steel for bridge structure and production method thereof | |
| CN106756471A (en) | 345MPa grades of vanadium titanium microalloying anti-seismic structure hot continuous rolling steel band and preparation method thereof | |
| CN111471937B (en) | Low-cost chromium-containing Q460MC steel plate and production method thereof | |
| CN106834914A (en) | Deep-draw level Ti IF cold-rolled steel sheets and preparation method thereof | |
| CN104233064A (en) | 170MPa-grade cold-rolled phosphorized IF high-strength steel and production method thereof | |
| CN109385576A (en) | A kind of inexpensive X65 pipe line steel and its manufacturing method based on magnesium processing | |
| CN111218609A (en) | High-strength automobile structural steel plate for continuous annealing, cold rolling and stamping and production method thereof | |
| CN100560773C (en) | A kind of high-strength anti-fatigue steel products and manufacture method thereof | |
| CN101487097B (en) | High strength cold rolling packaging steel belt and production method thereof | |
| CN111575592B (en) | Low-alloy high-strength steel with yield strength of 460MPa and production method thereof | |
| CN104131238A (en) | High-formability high-weatherability ultrathin hot-rolled steel plate and CSP (compact strip production) technology thereof | |
| CN107699797A (en) | 390MPa levels continuous annealing cold rolled automobile structural steel and iron and its production method | |
| CN102912223A (en) | Production method for low-alloy medium-thick steel sheet | |
| CN105369134B (en) | 400MPa grades is exempted from pickling vehicle structure hot rolled steel plate and its production method | |
| CN102899557B (en) | Production method of low-alloy medium plate | |
| CN105239002B (en) | 340MPa grades of continuous annealing cold rolled automobile structural steel and iron and its production method | |
| CN112522594B (en) | Thin-specification fire-resistant weather-resistant steel plate/belt and production method thereof | |
| CN113234988B (en) | Method for producing weathering steel with yield strength of 700MPa grade by online quenching and product thereof | |
| CN113201682B (en) | Bainite weathering 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 | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20150916 Termination date: 20170608 |