CN102650024A - Medium plate made of duplex stainless steel with excellent low-temperature toughness and manufacturing method for medium plate - Google Patents

Medium plate made of duplex stainless steel with excellent low-temperature toughness and manufacturing method for medium plate Download PDF

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CN102650024A
CN102650024A CN201210165039XA CN201210165039A CN102650024A CN 102650024 A CN102650024 A CN 102650024A CN 201210165039X A CN201210165039X A CN 201210165039XA CN 201210165039 A CN201210165039 A CN 201210165039A CN 102650024 A CN102650024 A CN 102650024A
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stainless steel
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duplex stainless
temperature
austenite
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江来珠
张伟
宋红梅
王治宇
胡锦程
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Baoshan Iron and Steel Co Ltd
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Baoshan Iron and Steel Co Ltd
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The invention discloses a medium plate made of duplex stainless steel with excellent low-temperature toughness and a manufacturing method for the medium plate. The duplex stainless steel comprises the following chemical components in weight percentage: 0.01-0.10 percent of C, 0.2-1.0 percent of Si, 2.0-3.5 percent of Mn, 20.0-21.5 percent of Cr, 3.0-3.5 percent of Ni, 0.08-0.15 percent of N, 0.5-1.0 percent of W, 0.01-0.5 percent of Cu, 0.001-0.005 percent of B, 0.05-0.25 percent of V and the balance Fe and unavoidable impurities. The stainless steel is proper in phase proportion and excellent in low-temperature toughness through controlling component proportion. Meanwhile, the length-width ratio of the austenite phase of the stainless steel along the rolling direction is enabled to be less than 3 through a special rolling process, and thus, the stainless steel is prevented from being excessively lengthened along the rolling direction. The duplex stainless steel is excellent in low-temperature toughness along the longitudinal direction and the lateral direction. The longitudinal impact value and the lateral impact value are greater than 220J at the temperature of -40 DEG C, and the longitudinal impact value and the lateral impact value are greater than 200J at the temperature of -80 DEG C. The duplex stainless steel can be widely applied to the field of coasting buildings and petrochemical engineering under the cold condition.

Description

A kind of duplex stainless steel plate and method of manufacture thereof of excellent in low temperature toughness
Technical field
The present invention relates to duplex stainless steel and method of manufacture thereof, especially a kind of duplex stainless steel of excellent in low temperature toughness and method of manufacture thereof.
Background technology
Duplex stainless steel is made up of ferritic and austenite two-phase, and wherein every phase ratio is no less than 30%.Because the characteristic of two-phase structure makes duplex stainless steel have the advantage of ferritic stainless steel and austenitic stainless steel concurrently, with the ferritic stainless steel ratio, its toughness height, brittle transition temperature are low, intergranular corrosion resistance and good welding performance.Kept the advantage that the ferritic steel thermal conductivity is high, the coefficient of expansion is little simultaneously.Its ys is compared with austenitic stainless steel and is significantly improved, and anti-chloride stress cracking corrosion cracking ability has the excellent anti-pitting and the ability of crevice corrosion simultaneously apparently higher than the austenitic stainless steel of 300 series.
Nineteen sixty-eight the stainless steel precision sweetening process--the invention of argon oxygen decarburization (AOD) makes the generation of a series of new type of stainless steel become possibility.One of many progress that AOD brought are the interpolations of alloying element nitrogen.Duplex stainless steel adds nitrogen can make the toughness of heat affected zone under the welded condition and the performance that erosion resistance approaches matrix metal, and nitrogen has also reduced the formation speed of phase between poisonous metal.Nitrogenous duplex stainless steel is called as s-generation duplex stainless steel.The 2205th, the representative steel grade of s-generation dual phase steel also is widely used in a plurality of fields such as offshore oil platform, chemical industry, papermaking.
Cr content is below 22%, and nickel content is low, and the duplex stainless steel that does not simultaneously contain molybdenum, tungsten or only contain a spot of molybdenum, tungsten is called as economical diphase stainless steel, owing to adopt N, Mn for Ni, so cost is lower, is the ideal material that replaces traditional austenitic stainless steel.In fact, got into since 2000, the development of duplex stainless steel presents two kinds of trend.Further improve steel interalloy constituent content on the one hand to obtain more HS and better solidity to corrosion; Turn to exploitation to contain Cr amount about 21% on the other hand; Low nickel amount and do not contain molybdenum or only contain the economical diphase stainless steel of a small amount of molybdenum; With the cost and the price of reduction duplex stainless steel, thereby increase duplex stainless steel and the stainless competitive edge of other types.
Impact property is one of most critical performance of duplex stainless steel.The patent EP1327008 of EUROPEAN PATENT OFFICE has announced a kind of austenite-ferrite duplex stainless steel; Its composition range (weight %): 0.02 ~ 0.07%C, 3.0 ~ 8.0%Mn, 19.0 ~ 23.0%Cr, 1.1 ~ 1.7%Ni, 0.1 ~ 2.0%Si, 0.15 ~ 0.3%N, the alloying element that possibly comprise have the Cu that is not more than 1.0% Mo or W, is not more than 1.0%, 0.003 ~ 0.005%B ,≤0.004%Ti ,≤0.002%Nb ,≤0.04%V ,≤0.03%Ce or Ca, surplus is Fe or unavoidable impurities.After 1050 ℃ of anneal; This dual phase steel has higher intensity, superior corrosion resistance ability and welding property; Ni constituent content in the steel is reduced to 1.1 ~ 1.7% simultaneously; Compare with the austenitic stainless steel of widespread use and to have the significantly reduced characteristic of cost, its application target is to replace 304 austenitic stainless steels.But because Ni content is below 1.7% in the alloy, therefore along with the reduction of temperature, its toughness (impact value) will significantly descend.A kind of austenite-ferrite duplex stainless steel that patent CN101215674 announces; Its composition range of its composition range (weight %): 0~0.04%C, 5.0~7.0%Mn, 18.0~20.0%Cr, 0~1.0%Si, 0.15~0.25%N, 0.001 ~ 0.1%B, 0.005 ~ 0.20% Rare-Earth Ce or Y.Material does not contain Ni and Mo, and anti-spot corrosion equivalent value PREN=Cr%+3.3Mo%+20N% is lower.European patent EP 1867748A1 discloses a kind of ferritic-austenitic phase duplex stainless steel, and its composition characteristic is: C≤0.05%, Cr:21 ~ 25%, Ni:1 ~ 2.95%, N:0.16 ~ 0.28%; Mn≤2.0%, Mo+W/2≤0.50%, Mo≤0.45%, W≤0.15%, Si≤1.4%; Al≤0.05%, Cu:0.11 ~ 0.50%, S≤0.01%, P≤0.04%, B≤0.005%; Co≤0.5%, REM≤0.1%, V≤0.5%, Ti≤0.1%; Nb≤0.3%, Mg≤0.1%, material have good solidity to corrosion and intensity, but impact value is not more than 51J its-50 ℃ the time.
Summary of the invention
The object of the present invention is to provide a kind of duplex stainless steel plate and method of manufacture thereof of excellent in low temperature toughness; This stainless material longitudinally and laterally all has good low-temperature flexibility; The vertical and horizontal impact value is greater than 220J in the time of-40 ℃, and the vertical and horizontal impact value is greater than 200J in the time of-80 ℃.
Research shows that austenitic stainless steel has best low-temperature flexibility, does not occur basically when its notched bar impact strength is reduced to-200 ℃ with temperature changing, and remains on more than the 200J; Duplex stainless steel impact property when room temperature is suitable with austenitic stainless steel, along with temperature reduces, remains unchanged earlier, occurs subsequently descending.Reason is to contain in the duplex stainless steel 50% ferritic phase; And there is low temperature tough-brittle transition (Ductile to brittle transition in ferritic; Be called for short DBT); Cause duplex stainless steel impelling strength to reduce and occur reducing, thereby low-temperature flexibility becomes the key parameter of weighing its mechanical property with temperature.For example typical economical diphase stainless steel S32101 is in the time of-40 ℃, and longitudinally (being the rolling direction of steel plate) impact value of detecting is 160J, and laterally the rolling direction of steel plate (promptly perpendicular to) impact value of detecting is about 80J; Probe temperature is reduced to-80 ℃, and laterally the rolling direction of steel plate (promptly perpendicular to) impact value of detecting is about 60J.The risk increase that the reduction of impact property (especially horizontal) will cause the material fragility fracture or lose efficacy, thus limited it in cryogenic application.
The principal element that influences the duplex stainless steel low-temperature flexibility comprises:
(1) alloying element
Nickel is to form austenite and the element that enlarges the austenite phase region strongly, and along with the reduction of nickel content, low-temperature impact toughness reduces rapidly, and nickel is one of key factor of decision impelling strength.Nitrogen also is strong formation and stable austenite, the element that enlarges the austenite phase region, and its ability far surpasses nickel element, but nitrogen reduces the duplex stainless steel low-temperature flexibility, and along with nitrogen content increases, impelling strength significantly descends during low temperature.
(2) organizer to the influence of grain fineness number
The directivity impact toughness of tissue has remarkable influence.Usually, along roll to impact property higher, perpendicular to rolling, especially when low temperature, show more obviously to being that horizontal impact property is then significantly lower.Reason is that austenite is elongated along rolling direction, presents typical strip tissue signature.This edge is rolled to the extended austenite and has been caused the impact value of both direction to differ greatly; Bruise often is formed by connecting in micro-cavity; This cavity preferentially takes place with phase boundary in ferritic phase, can more easily expand along phase boundary with in ferritic phase perpendicular to the crackle that rolls to sample, causes final fracture; Crack propagation along rolling to sample is then different; Need pass the austenite phase, the banded preferably austenite of these plasticity has stoped the expansion of crackle, thereby shows high toughness.The grain fineness number of duplex stainless steel plays an important role to ys and toughness, and tiny crystal grain helps to obtain higher yield strength and toughness.
(3) phase ratio
The phase ratio exists than remarkable influence mechanical property, and usually, the austenite content height helps improving impelling strength.The phase ratio also influences corrosion resistance nature simultaneously, therefore needs to select suitable phase ratio, to obtain excellent comprehensive performances.
In sum, design of the present invention is following:
N content is controlled at 0.08 ~ 0.15%, and Ni content is controlled at 3.0 ~ 3.5%, Mn content 2.0 ~ 3.5%, austenite phase content 50 ~ 58%, control austenite hand down roll to the dimension ratio of width less than 3, guarantee that its austenite is mutually along not rolling to excessive elongation.Further, through special rolling technology, promptly rolling technology is for earlier being rolled down to 35 ~ 45% of strand along a direction broadening, change 90 ° of steel then after, be rolled down to desired thickness, the total compression amount satisfies more than 70%, both direction draught ratio is near 1:1 simultaneously; Steel plate after rolling is carried out annealing and pickling; Its annealing temperature is controlled at 1030 ~ 1100 ℃; Guarantee austenite phase content 50 ~ 58%; Crucially control austenite hand down roll to the dimension ratio of width less than 3, guarantee material along roll to perpendicular to rolling to all obtaining excellent toughness, eliminate the flexible directivity.Material longitudinally He laterally all has good low-temperature flexibility, and the vertical and horizontal impact value is greater than 220J in the time of-40 ℃, and the vertical and horizontal impact value is significantly higher than S32101 greater than 200J in the time of-80 ℃.Material contains W 0.5 ~ 1.0%, pitting potential greater than 400mv simultaneously, and the CPT temperature is higher than 8 ℃.
For realizing above-mentioned purpose, technical scheme of the present invention is:
A kind of duplex stainless steel plate of excellent in low temperature toughness, its chemical component weight per-cent is: C 0.01 ~ 0.10%, and Si 0.2 ~ 1.0%; Mn 2.0 ~ 3.5%, and Cr 20.0 ~ 21.5%, and Ni 3.0 ~ 3.5%; N 0.08 ~ 0.15%, and W 0.5 ~ 1.0%, and Cu 0.01 ~ 0.5%; B 0.001 ~ 0.005%, and V 0.05 ~ 0.25%, and all the other are Fe and inevitable impurity.
Preferably, austenite phase content 50 ~ 58% in the tissue of steel.
Further, the present invention provides a kind of method of manufacture of duplex stainless steel plate of excellent in low temperature toughness, may further comprise the steps:
Smelt by following weight percent proportioning: C 0.01 ~ 0.10%, and Si 0.2 ~ 1.0%, and Mn 2.0 ~ 3.5%, and Cr 20.0 ~ 21.5%; Ni 3.0 ~ 3.5%, and N 0.08 ~ 0.15%, and W 0.5 ~ 1.0%, and Cu 0.01 ~ 0.5%; B 0.001 ~ 0.005%, and V 0.05 ~ 0.25%, and all the other are Fe and inevitable impurity; Smelting process can select vacuum induction to smelt, and the outer concise LF stove of electric furnace-argon oxygen decarburization AOD or electric furnace-argon oxygen decarburization AOD-stove is smelted.
Molten steel is carried out die casting or continuous casting; The control superheating temperature is about 30 ~ 50 ℃ during die casting, or adopts continuous casting process, and the control superheating temperature is 30 ~ 50 ℃ during continuous casting; Through controlling the pore that superheating temperature avoids the effusion of nitrogen to cause, because pore will cause hot workability, mechanics and corrosion resistance nature to worsen; In addition, the slab pulling rate is 0.8 ~ 2m/min during continuous casting;
With strand put into process furnace be heated to 1100 ~ 1250 ℃ and the insulation after; On single stand mill, carry out hot rolling; Rolling technology is for earlier being rolled down to 35 ~ 45% of strand along a direction broadening, change 90 ° of steel then after, be rolled down to desired thickness; The total compression amount satisfies more than 70%, and both direction draught ratio is near 1:1 simultaneously; Steel plate after rolling is carried out annealing and pickling; Its annealing temperature is controlled at 1030 ~ 1100 ℃; Guarantee austenite phase content 50 ~ 58%, crucially control austenite hand down roll to the dimension ratio of width less than 3, guarantee that its austenite is mutually along not rolling to excessive elongation.
Below with regard to the present invention the selection reason and the mechanism of action of composition are explained as follows:
Carbon carbon is strong austenite former, can replace Ni to a certain extent, promotes austenite to form, and the stable austenite tissue, can improve stainless intensity simultaneously.But when carbon content was too high, carbon combined the back to form rich chromium carbide at crystal boundary with chromium, cause intergranular corrosion.In addition, the rich chromium carbide of formation also reduces the impelling strength of steel.Cross low carbon content and will increase difficulty and cost in the preparation process.Therefore, the design carbon content is 0.01% ~ 0.10% in the steel of the present invention.
Silicon silicon is the element that contains usually in the Manufacture Of Iron And Steel By Melting.In duplex stainless steel, silicon is that ferritic forms and stable element.Silicon is used for deoxidation in fusion process, silicon can improve the hot strength of ferritic phase simultaneously, contains the silicon more than 0.2% in the therefore general dual phase steel.Will reduce the solubleness of nitrogen when but silicone content is too high, and quicken separating out of intermetallic phase.Therefore, design of Si content is 0.2% ~ 1.0% in the steel of the present invention.
Manganese manganese is that a kind of austenite forms and stable element, can utilize manganese to replace nickel to a certain extent, obtains austenite structure, and the interpolation of manganese simultaneously can significantly improve the solubleness of nitrogen.But manganese all is negative to the influence of stainless erosion resistance basically, so control Mn content is 2.0 ~ 3.5% in the steel of the present invention.
Chromium chromium is the most important element that steel obtains corrosion resistance nature.The minimum chromium content that usually obtains erosion resistance is 12%.But when chromium content is low, the Fe-Cr binary phase diagram shows martensitic phase will occur, and the raising of Cr content simultaneously can significantly strengthen corrosion resistance nature, so Cr content is controlled at more than 18% in the steel of the present invention.But when the Cr too high levels, will increase intermetallic phase and separate out, because Cr is main ferrite former, therefore too high Cr will need corresponding high Ni equivalent to cooperate with it simultaneously, to guarantee to obtain duplex structure.Therefore, chromium content is controlled at 20.0% ~ 21.5% in the steel of the present invention.
Nickel nickel is basic austenite former, is austenizer main in austenitic stainless steel and the duplex stainless steel.And can improve the impelling strength of steel; Reduce the tough-crisp transition temperature (Ductile-bri ttle transition temperature is called for short DBTT) of steel, at nickel content less than 4 ~ 5% o'clock; Along with nickel content increases, impelling strength especially low-temperature impact toughness significantly improves.But because nickel costs an arm and a leg; It is a crucial difficult problem that reduces the Stainless Steel Production cost; Therefore nickel content is controlled at 3.0% ~ 3.5% in the steel of the present invention; To guarantee that Mn in the steel, N still have the phase ratio near 50:50 after reducing, and guarantee that simultaneously steel has excellent impact toughness under room temperature especially low temperature.
Nitrogen nitrogen element is a kind of strong austenite former.Nitrogen is to form and stable austenite key factor mutually in the dual phase steel.The adding of nitrogen simultaneously helps improving the intensity and the corrosion resistance nature of steel, especially anti-pitting attack performance and slit and corrosion resistant performance.When but nitrogen content is too high, with increasing the risk that forms mutually between nitrogen containing metal, the raising that improves melting and hot worked difficulty, especially nitrogen content simultaneously will cause serious hot rolling limit to split rate, cause being difficult to producing existing producing on the line.Especially, the too high ductile-brittle transition temperature of alloy that causes of nitrogen content raises, and reduces its impelling strength when low temperature.Therefore, nitrogen in steel content of the present invention is controlled at 0.08% ~ 0.15%.
Tungsten tungsten is very beneficial for improving the corrosion resistance nature of steel, and its mechanism is to stablize passive film and promote the enrichment of chromium element in passive film, and the main effect of adding tungsten is to improve erosion resistance.Tungsten can also reduce the activity at austenite/ferritic phase interface, suppresses the formation of intermetallic phase.Promote intermetallic phase to generate when but W content is too high on the contrary.Therefore W content is controlled at 0.5 ~ 1.0% in the steel of the present invention.
Copper copper is a kind of austenite former, and the adding of copper can improve the erosion resistance of dual phase steel in reductive acid, helps improving the slit and corrosion resistant performance simultaneously.But be unfavorable for hot workability during the copper too high levels.Therefore copper content is controlled at 0.01 ~ 0.5% in the steel of the present invention.
Boron; The interpolation of vanadium trace B can thinning microstructure, improves grain-boundary strength, improves thermoplasticity; But excessive interpolation boron will cause the material hot workability to worsen on the contrary; Therefore the present invention finds in this alloy system through exploring, and adds 0.001%≤B≤0.005% and can obtain best hot workability; The main effect of vanadium is a thinning microstructure, improves the molten steel purity, improves hot workability, and its content is controlled at below 0.05 ~ 0.25%.
The present invention makes it compared with prior art owing to adopted above technical scheme, has the following advantages and positively effect:
(1) N content is controlled at 0.08 ~ 0.15%, Ni content is controlled at 3.0 ~ 3.5%, and Mn content 2.0 ~ 3.5% when guaranteeing that material obtains suitable phase ratio, reduces the DBTT temperature, improves its toughness when low temperature;
(2) Mn content is controlled to 2.0 ~ 3.5%; When improving N solubleness, effectively reduce the disadvantageous effect of manganese, add 0.5 ~ 1.0%W simultaneously corrosion resistance nature; Improve the especially anti-pitting attack property of erosion resistance of alloy; The pitting potential of material is greater than 400mv, and the CPT temperature is higher than 8 ℃, is superior to 304 traditional austenitic stainless steels;
(3) through special rolling technology, reduce the directivity of material structure and performance, the control austenite hand down roll to the dimension ratio of width less than 3, guarantee material along roll to perpendicular to rolling to all obtaining excellent toughness, elimination flexible directivity.Material longitudinally He laterally all has good low-temperature flexibility, and the vertical and horizontal impact value is greater than 220J in the time of-40 ℃, and the vertical and horizontal impact value is significantly higher than S32101 greater than 200J in the time of-80 ℃.
(4) this duplex stainless steel existing stainless steel capable of using produces the line batch process; Concrete preparation method is casting after vacuum induction furnace, electric furnace-AOD stove smelting or electric furnace-AOD-LF stove are smelted, and the control superheating temperature is about 30 ~ 50 ℃ when die casting, and cooperates quick cooling; Or adopt cooling rate continuous cast method faster; Avoid the effusion of nitrogen, the control superheating temperature is 30 ~ 50 ℃ during continuous casting, and the slab pulling rate is 0.8 ~ 2m/min; Earlier be rolled down to 35 ~ 45% of strand during hot rolling along a direction broadening, change 90 ° of steel then after, be rolled down to desired thickness, the total compression amount satisfies more than 70%, both direction draught ratio is near 1:1 simultaneously; Steel plate after rolling is carried out annealing and pickling, and its annealing temperature is controlled at 1030 ~ 1100 ℃, and above-mentioned technology utilization existing product line and equipment all can be realized.
(5) comprehensive cost of material is lower than austenitic stainless steel 304 and 316, can be used for replacing 304 and 316, especially the lower temperature application field.
Description of drawings
Fig. 1 is embodiments of the invention 1 alloy metallographs (along rolling direction).
Fig. 2 is embodiments of the invention 1 alloy metallographs (perpendicular to rolling direction).
Fig. 3 is Comparative Examples 2 alloy metallographs (along rolling direction) of the present invention.
Embodiment
The embodiment of the invention is an example with the Production Flow Chart that electric furnace-AOD smelts: adding electric furnaces such as ferrochrome, ferronickel and steel scrap are melted; Pour molten steel into the AOD stove after melting clearly; In the AOD stove, take off C, take off S and increase N, control the blowing of N; When the smelting composition reaches requirement, pour molten steel into tundish, and on vertical-bending caster, cast.The superheating temperature of continuous casting is 30 ~ 50 ℃, and the slab pulling rate is 0.8 ~ 2m/min.With strand put into process furnace be heated to 1100 ~ 1250 ℃ and the insulation after; On single stand mill, carry out hot rolling; Rolling technology is for earlier being rolled down to 35 ~ 45% of strand along a direction broadening, change 90 ° of steel then after, be rolled down to desired thickness; The total compression amount satisfies more than 70%, and both direction draught ratio is near 1:1 simultaneously; Steel plate after rolling is carried out annealing and pickling; Its annealing temperature is controlled at 1030 ~ 1100 ℃; Guarantee austenite phase content 50 ~ 58%; Crucially control austenite hand down roll to the dimension ratio of width less than 3, guarantee its austenite mutually along not rolling, thereby obtain good impact property and corrosion resistance nature to excessive elongation.
Table 1 is depicted as chemical ingredients and the key manufacturing technology and the material property of steel grade of the present invention, and table 1 has provided the routine as a comparison duplex stainless steel S32101 that has developed at present and the chemical ingredients of substituted object 304 austenitic stainless steels of steel plan of the present invention simultaneously.
The alloy of embodiment 1 is along the rolling direction metallograph (austenite accounts for 58% mutually) as shown in Figure 1 of (claiming vertically again); The alloy of embodiment 1 is as shown in Figure 2 perpendicular to the alloy metallograph of rolling direction (claiming laterally again), and the alloy of Comparative Examples 2 is as shown in Figure 3 along the metallograph of rolling direction.Table 1 gives the mechanical property and the corrosion resistance nature of steel of the present invention and contrast steel grade, especially-40 ℃ of impelling strength with-80 ℃.Wherein the duplex stainless steel metallographic specimen is through electrolytic corrosion, and etching reagent is 40gKOH+100mlH 2O, corrosion current 0.3 ~ 0.8A/cm 2Mechanical property is all taken from the hot-roll annealing plate; Wherein impact property according to the GB/T229 summer than v-notch normal of impact; Along rolling direction (claim not only vertically) with perpendicular to rolling direction (but also claiming laterally) sampling, probe temperature is respectively 20 ℃ respectively for specimen size 10 * 10 * 55mm, sample;-40 ℃ ,-80 ℃.
Table 1
Figure BDA00001678347800081
Figure BDA00001678347800091
Visible by Fig. 1, Fig. 2 and Fig. 3; Steel of the present invention is owing to adopt suitable element proportioning; Obtained suitable phase ratio after the annealing; Especially through to the special control of rolling technology, austenite hand down roll to the dimension ratio of width less than 3, guarantee that its austenite is mutually along not rolling to excessive elongation; And the metallographic of conventional products such as Fig. 3, its austenite significantly elongates along rolling direction, and long-width ratio even surpass more than 10 times causes material property directivity to occur.The visible steel of the present invention of performance longitudinally and laterally all has good low-temperature flexibility in the table 1; The vertical and horizontal impact value is greater than 220J in the time of-40 ℃; The vertical and horizontal impact value is significantly higher than S32101 greater than 200J in the time of-80 ℃, and the pitting potential of material is greater than 400mv simultaneously; The CPT temperature is higher than 8 ℃, is superior to 304 traditional austenitic stainless steels.Compare with substituted object 304 austenitic stainless steels of steel plan of the present invention (containing 8% nickel); Nickel in the steel is replaced by part; Can further reduce material cost; Have higher corrosion resistance nature and intensity simultaneously, can under room temperature and low temperature, replace nickel content, remedy the low temperature field that S32101 type duplex stainless steel is difficult to use in the existing Comparative Examples 2 up to 304 austenitic stainless steels more than 8%.
Be noted that above enumerate be merely specific embodiment of the present invention, obviously the invention is not restricted to above embodiment, many similar variations are arranged thereupon.If those skilled in the art all should belong to protection scope of the present invention from all distortion that content disclosed by the invention directly derives or associates.

Claims (2)

1. the duplex stainless steel plate of an excellent in low temperature toughness, its chemical component weight per-cent is: C 0.01 ~ 0.10%, and Si 0.2 ~ 1.0%; Mn 2.0 ~ 3.5%, and Cr 20.0 ~ 21.5%, and Ni 3.0 ~ 3.5%; N0.08 ~ 0.15%, W 0.5 ~ 1.0%, and Cu 0.01 ~ 0.5%; B 0.001 ~ 0.005%, and V 0.05 ~ 0.25%, and all the other are Fe and inevitable impurity.
2. the method for manufacture of the duplex stainless steel plate of a kind of excellent in low temperature toughness as claimed in claim 1 is characterized in that, may further comprise the steps:
1) smelt by said composition, die casting or continuous casting form strand; The control superheating temperature is 30 ~ 50 ℃ when adopting die casting, and the control superheating temperature is 30 ~ 50 ℃ when adopting continuous casting, and the slab pulling rate is 0.8 ~ 2m/min during continuous casting;
2) strand is put into process furnace and is heated to 1100 ~ 1250 ℃ and insulation after, on single stand mill, carry out hot rolling, rolling technology is for earlier being rolled down to 35 ~ 45% of strand along a direction broadening; After changeing 90 ° of steel then; Be rolled down to desired thickness, the total compression amount satisfies more than 70%, and both direction draught ratio is near 1:1 simultaneously; The control austenite hand down roll to the dimension ratio of width less than 3, guarantee that its austenite is mutually along not rolling to excessive elongation;
3) steel plate after rolling is carried out annealing and pickling, its annealing temperature is controlled at 1030 ~ 1100 ℃, guarantees austenite phase content 50 ~ 58%.
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CN102994903A (en) * 2012-12-10 2013-03-27 上海大学 Duplex stainless steel with paradoxical phase proportion change and preparation method thereof
CN105256121A (en) * 2015-10-21 2016-01-20 苏州雷格姆海洋石油设备科技有限公司 Thermal treatment method for improving low-temperature toughness and corrosion resistance of 22Cr-type stainless steel forging
CN109487174A (en) * 2018-11-30 2019-03-19 山西太钢不锈钢股份有限公司 A kind of two phase stainless steel manufacturing method of plate thereof for taking into account elevated temperature strength and low-temperature flexibility
CN109777938A (en) * 2019-01-08 2019-05-21 钢铁研究总院 A kind of process improving two phase stainless steel impact flexibility
CN115287521A (en) * 2022-07-20 2022-11-04 山西太钢不锈钢股份有限公司 Method for improving low-temperature impact toughness of economical duplex stainless steel medium plate for nuclear power

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CN102994903A (en) * 2012-12-10 2013-03-27 上海大学 Duplex stainless steel with paradoxical phase proportion change and preparation method thereof
CN105256121A (en) * 2015-10-21 2016-01-20 苏州雷格姆海洋石油设备科技有限公司 Thermal treatment method for improving low-temperature toughness and corrosion resistance of 22Cr-type stainless steel forging
CN105256121B (en) * 2015-10-21 2017-07-28 苏州雷格姆海洋石油设备科技有限公司 A kind of heat treatment method of raising 22Cr type stainless steel forgings low-temperature flexibilities and decay resistance
CN109487174A (en) * 2018-11-30 2019-03-19 山西太钢不锈钢股份有限公司 A kind of two phase stainless steel manufacturing method of plate thereof for taking into account elevated temperature strength and low-temperature flexibility
CN109777938A (en) * 2019-01-08 2019-05-21 钢铁研究总院 A kind of process improving two phase stainless steel impact flexibility
CN109777938B (en) * 2019-01-08 2020-05-26 钢铁研究总院 Process method for improving impact toughness of duplex stainless steel
CN115287521A (en) * 2022-07-20 2022-11-04 山西太钢不锈钢股份有限公司 Method for improving low-temperature impact toughness of economical duplex stainless steel medium plate for nuclear power

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Application publication date: 20120829