CN101765673B - Hot-rolled shape steel for crude oil tanks and process for manufacturing the same - Google Patents
Hot-rolled shape steel for crude oil tanks and process for manufacturing the same Download PDFInfo
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Abstract
A hot-rolled shape steel for crude oil tanks which has a composition containing by mass C: 0.001 to 0.16%, Si: 0.01 to 1.5%, Mn: 0.1 to 2.5%, P: 0.025% or below, S: 0.01% or below, Al: 0.005 to 0.1%, N: 0.001 to 0.008%, W: 0.001 to 0.5% and Cr: 0.06 to less than 0.20% with the balance consisting of Fe and unavoidable impurities and a ferrite/pearlite microstructure containing deformed ferrite in an amount of 10% or above in terms of area ratio based on the whole microstructure and which exerts excellent resistance to uniform or local corrosion independent of coating and exhibits a strength corresponding to YP of 315MPa or above; and a process for manufacturing the steel.
Description
Technical field
The present invention relates to be used for the hot-rolled steel section of petroleum tank (crude oil tank).The present invention be more particularly directed to, when being used for the longeron of petroleum tank (vertically material) etc., have the local corrosion (localcorrosion) that can reduce significantly under naked state (naked state) and the primer coating state (primary coate state), the superior corrosion resistance of general corrosion (general corrosion), and have yielding stress YP (yield strength) for 315MPa is above, tensile strength TS (tensile strength) is 440MPa above high-intensity hot-rolled shape steel for crude oil tanks and manufacture method thereof.
Here, petroleum tank of the present invention be oil tanker (oil tanker) cargo tank (oil tank), be used for conveying crude oil oil tank, be used to store the general name of the oil tank etc. of crude oil.And hot-rolled steel section is meant the shaped steel (relative therewith, as to be to obtain the net shape of shaped steel by Plate Steel being cut into welding after the predetermined size with Plate Steel as the shaped steel of former material) that is configured as net shape by hot rolling.Particularly, be meant the equal legged angle (equal leg angle:AB) made by hot rolling, unequal-angle bar (unequal leg angle:ABS), angle of unequal legs ﹠ thickness (unequal leg andthickness angle:NAB), channel-section steel (channel beam:CB), flat bulb steel (bulb plate:BP), T-steel (T-bar) etc.
Background technology
For explosion-proof (explosion prevention), in the petroleum tank of oil tanker, fill rare gas element (inert gas: with O
2: 5 volume %, CO
2: 13 volume %, SO
2: 0.01 volume %, surplus N
2The waste gas (exhaust gas) of forming the boiler of (representative composition) or engine etc. for representativeness).Therefore as can be known, because the O that comprises in the waste gas
2, CO
2, SO
2, the H that volatilizes from crude oil
2Corrosive gasess such as S (corrosive gas), therefore general corrosion takes place in the upper inside surface (upperdeck (upper deck) the inside) at petroleum tank.And, above-mentioned H
2S is oxidized owing to the katalysis (catalytic effect) of the iron rust (iron rust) of corrosion generation, generates solid S, and these S exist with stratiform (layered shape) in iron rust.And these corrosion products (corrosion product) are peeled off (peeled off) easily, and pile up (deposit) bottom at petroleum tank.Therefore, in the dock inspection (doc inspection) of per oil tanker that carried out in 2.5 years, spend maintenance or sedimental removing that great labour, expense carry out oil tank top.
On the other hand; thought in the past; because the effect of corrosion inhibition (corrosion inhibition effect) of the protective membrane that comes from crude oil (hereinafter referred to as " crude oil protective membrane " (crude oilprotective film)) that generates on the effect of corrosion inhibition of crude oil itself and the petroleum tank internal surface, the employed steel of the base plate of the petroleum tank of oil tanker (bottom plate) do not corrode.But the local corrosion of bowl type (form of a bowl) has taken place in discovered in recent years, the steel of oil tank bottom plate.
As the reason that the local corrosion of this bowl type takes place, can enumerate: (1) exists what dissolved high density is the water of condensation (condensed water) of the salt (salts) of representative with sodium-chlor; (2) come off (the peeling off) of the crude oil protective membrane that causes by over-drastic washing; (3) high densityization of the sulfide that contains in the crude oil (sulfide materials); (4) be used for the O that explosion-proof rare gas element contains
2, CO
2, SO
2High densityization; (5) influence of microorganism (microorganism) etc., but these all are to infer, can't conclude clear and definite reason.
Suppressing the effective means of aforesaid corrosive is that steel surface is implemented thick application (thick coating), and steel and corrosive environment (corrosive environment) are isolated.But the someone points out, because the surface covered of petroleum tank is huge, and just needs in about 10 years to be coated with once again, therefore petroleum tank is implemented coating and will spend a large amount of labour and expense in construction, inspection.In addition, also the someone points out, under the corrosive environment of petroleum tank, and for the situation of thick application, the corrosion of the damaged portion that promotes on the contrary to film.
Therefore, even proposed under the such corrosive environment of petroleum tank the steel that also has superior corrosion resistance.For example, anti-general corrosion and the good corrosion-resistant steel of anti-local corrosion are disclosed in the TOHKEMY 2003-082435 communique (patent documentation 1), wherein, above-mentioned corrosion-resistant steel is by add an amount of Si, Mn, P, S in the steel of C:0.01～0.3 quality %, further add Ni:0.05～3 quality %, and optionally add Mo, Cu, Cr, W, Ca, Ti, Nb, V, B obtains.
And, disclose in the TOHKEMY 2004-204344 communique (patent documentation 2) and had good anti-general corrosion and anti-local corrosion, and the corrosion-resistant steel that the corrosion product that can suppress to contain solid S generates, wherein, above-mentioned corrosion-resistant steel is by adding an amount of Si, Mn, P, S and Cu:0.01～1.5 quality %, Al:0.001～0.3 quality %, N:0.001～0.01% quality % in the steel of C:0.001～0.2 quality %, further adding Mo:0.01～0.2 quality % or W:0.01～0.5 at least a of quality % and obtain.Can optionally in this steel, add Ni, Co, Sb, Sn, Pb, As, Bi, Nb, V, Ti, Ta, Zr, B, Mg, Ca, Y, La, Ce, and allow that Cr is less than 0.1%.
In addition, as the corrosion-resistant steel material for ship and vessel that is suitable for ballast tank (ballast tank) etc., among the open communique WO of international application No. 2007/097142 (patent documentation 3) steel with following compositions composition being disclosed: makes C:0.03～0.25 quality %, in the steel of Si:0.05～0.50 quality %, contain an amount of Mn, P, S and Al:0.005～0.10 quality %, W:0.01～1.0 quality %, more than the Cr:0.01 quality % and less than 0.20 quality %, N:0.001～0.008 quality %, optionally contain Sb, Sn, Ni, Mo, Co, Nb, Ti, Zr, V, B, Ca, REM, Y, surplus is made of Fe and unavoidable impurities.In addition, illustration Plate Steel (thickplates) as steel.
Summary of the invention
But practical situation are, when the steel with above-mentioned patent documentation 1 and patent documentation 2 uses with steel as petroleum tank, though brought into play good inhibition effect for the general corrosion that takes place on petroleum tank top, but it is, not talkative abundant for the resistivity (hereinafter referred to as " anti-local corrosion ") of the local corrosion that takes place at petroleum tank base plate place.The purposes difference of patent documentation 3 can not realize as the optimization of petroleum tank with the erosion resistance of steel.
And,, advancing the high strength of the steel that are used for boats and ships from subduing cost by the reduction of usage quantity and guaranteeing the viewpoint of security.For example,, just progressively use yielding stress YP, and preferred tensile strength TS is the above high-strength material of 440MPa as more than the 315MPa as patent documentation 3 illustrated Plate Steels.When using this Plate Steel, general, intensity and flexible control are to realize by the condition of controlled rolling and accelerated cooling process (TMCP:Thermo-Mechanical Control Process, hot mechanical CONTROL PROCESS) is adjusted to optimum range.
On the other hand, vertical employed hot-rolled steel section such as material for example, because angle of unequal legs ﹠ thickness, T-steel and Plate Steel etc. are compared cross-sectional shape/size complexity, therefore is difficult to adopt the TMCP identical with Plate Steel as intensity and flexible control method.Particularly, for hot-rolled steel section owing to need when considering rolling bending, warpage midway, carry out the manufacturing of material, therefore for high strength to yielding stress YP be more than the 315MPa, need the manufacture method of research shaped steel uniqueness.
Therefore, the objective of the invention is to, even provide under the harsh like this corrosive environment of the petroleum tank of oil tanker, the influence of the existence of also not filmed, general corrosion and local corrosion are had superior corrosion resistance, and have hot-rolled shape steel for crude oil tanks and manufacture method thereof that YP is the above intensity of 315MPa.
The inventor thinks and the various factors of the local corrosion that participates in the petroleum tank base plate these factors combine is carried out various corrosion tests in order to finish above-mentioned problem, at first to extract.Consequently successfully reproduced the local corrosion that takes place at petroleum tank base plate place, essential factor and corrosion mechanism about local corrosion obtain following opinion.
In the bowl type local corrosion that the petroleum tank base plate place of reality takes place, the O that contains in the liquid
2(oxygen) and H
2S (hydrogen sulfide) plays a significant role as the corrosive essential factor, particularly at O
2And H
2S coexistence and O
2Dividing potential drop and H
2Under the low corrosive environment of S dividing potential drop both, particularly, at O
2Dividing potential drop: 2～8 volume %, H
2S dividing potential drop: local corrosion easily takes place in the saturated aqueous solution of the gas of 5～20 volume %.That is, at low O
2Dividing potential drop and low H
2Under the corrosive environment of S dividing potential drop, H
2S is oxidized and separate out solid S, forms local element between petroleum tank base plate and the solid S, therefore in steel surface generation local corrosion.Particularly find have chlorion (Cl
-) sour environment under, local corrosion is grown by promotion.
Therefore, the inventor gives above-mentioned low O to various alloying elements
2Dividing potential drop and low H
2The influence that the local corrosion that the environment of S dividing potential drop takes place is down brought is studied.Consequently, by adding W and Cr, use under the environment for use of steel at petroleum tank, rusty scale (rust layer) densification (densified) that surface of steel plate forms, anti-local corrosion and anti-general corrosion raising, and Sn, Sb or Mo are added with the rusty scale that helps generate the densification that contains W, and anti-local corrosion and anti-general corrosion are further improved.That is, find mainly by suitably containing W and Cr, and suitably contain Sn, Sb, Mo, can access all good petroleum tank steel of anti-local corrosion and anti-general corrosion.
And find, if with above-mentioned steel in its surface coated contain the state use down of the priming paint (primer) of Zn, then this coating life (coating layer life) significant prolongation, and anti-local corrosion and anti-general corrosion also improve.
And find, realize the high strength of hot-rolled steel section in order not hinder productivity (productivity), weldability (weldability) etc., by (two-phase region of α+γ) is rolling, and (it is effective that hot rolling during (γ+α) region) imports processing ferrite (strain hardening ferrite).
The present invention is based on above-mentioned opinion and further studies and finish.
Promptly, the present invention is a kind of hot-rolled shape steel for crude oil tanks, it is characterized in that, having following one-tenth is grouped into: contain C:0.001～0.16 quality %, Si:0.01～1.5 quality %, Mn:0.1～2.5 quality %, below the P:0.025 quality %, below the S:0.01 quality %, Al:0.005～0.1 quality %, N:0.001～0.008 quality %, more than W:0.001～0.5 quality % and the Cr:0.06 quality % and less than 0.20 quality %, surplus is made of Fe and unavoidable impurities, have the microstructure (microstructure) that is made of ferrite and perlite (peralite), described ferrite contains with respect to whole tissue counts processing ferrite (strain hardening ferrite) more than 10% with area occupation ratio (area ratio).
Above-mentioned hot-rolled shape steel for crude oil tanks of the present invention on the basis that mentioned component is formed, preferably also contains the composition that belongs at least 1 group in following A～D group.
A group: be selected from a kind or 2 kinds among Sn:0.005～0.3 quality % and Sb:0.005～0.3 quality %;
B group: Mo:0.001～0.5 quality %;
C group: be selected from Nb:0.001～0.1 quality %, V:0.002～0.1 quality %, Ti:0.001～0.1 quality % and B:0.01 quality % in following more than a kind or 2 kinds;
D group: be selected from a kind or 2 kinds among Ca:0.0002～0.005 quality % and REM:0.0005～0.015 quality %.
And it is that 315MPa is above, tensile strength TS is the above intensity of 440MPa that above-mentioned hot-rolled shape steel for crude oil tanks of the present invention preferably has yielding stress YP.
And hot-rolled shape steel for crude oil tanks of the present invention preferably has zinc rich primer (zinc-primer) and films on its surface.
And the present invention is a kind of manufacture method of hot-rolled shape steel for crude oil tanks, it is characterized in that, is heated to after 1000～1350 ℃, carries out hot rolling and make in the method for shaped steel will having the former material of steel that mentioned component forms, and makes Ar
3The following rolling rate of accumulation (total reductionunder α+γ region) of transformation temperature is 10～80%, rolling end temp (finishing temperature) is (Ar
3Transformation temperature-30 ℃)～(Ar
3Transformation temperature-180 ℃) implements above-mentioned hot rolling under the condition, put cold (aircooling) then.
And manufacture method of the present invention is preferably in above-mentioned hot rolling, and the temperature head of different sites ((with reference to embodiment) such as long limit, minor face, web, the edges of a wing) that makes rolling shaped steel midway in 50 ℃, is implemented Ar in the surface temperature difference then
3The following rolling rate of accumulation of transformation temperature is 10～80%, rolling end temp is (Ar
3Transformation temperature-30 ℃)～(Ar
3Transformation temperature-180 ℃) hot rolling.
Description of drawings
Fig. 1 is the explanation embodiment 1 employed figure that is used for the testing apparatus of local corrosion test.
Fig. 2 is the explanation embodiment 2 employed figure that are used for the testing apparatus of general corrosion test.
[explanation of mark]
1,8: test film (test piece)
2,9: corrosion test groove (corrosion test bath)
3: thermostatic bath (constant-temperature bath)
4,11: import gas (supplied gas)
5,12: discharge gas (exhaust gas)
6: experimental liquid (test liquid)
7,13: water
10: temperature control panel (temperature-control plate)
Embodiment
(composition)
The qualification reason that the one-tenth that relates to hot-rolled shape steel for crude oil tanks of the present invention is grouped into describes.
C:0.001～0.16 quality %
C is the element that improves the intensity of steel, in order to obtain the desired intensity more than the YP:315MPa, need contain more than the 0.001 quality % in the present invention.But, surpass 0.16 quality % if contain, the toughness (toughness) of weldability and welding heat affected zone (HAZ:Heat Affected Zone) is reduced.Therefore, making C is the scope of 0.001～0.16 quality %.In addition, in order to have intensity and toughness two specific characters, the scope of preferred 0.01～0.15 quality % concurrently.
Si:0.01～1.5 quality %
Si adds as reductor (deoxidizing agent) usually, also is the element that improves the intensity of steel, needs among the present invention to contain more than the 0.01 quality %.But, surpass 1.5 quality % if add, the toughness of steel is reduced.Therefore, making Si is the scope of 0.01～1.5 quality %.In addition, Si forms protection against corrosion overlay film (corrosion resistant film) and has the effect that improves erosion resistance under sour environment.In order to obtain this effect, be preferably the scope of 0.2～1.5 quality %.
Mn:0.1%～2.5 quality %
Mn is the element that improves the intensity of steel, in the present invention in order to obtain desired intensity, needs to add more than the 0.1 quality %.But, surpass 2.5 quality % if add, the toughness of steel and weldability are reduced.Therefore, in the scope of 0.1～1.5 quality %, add Mn.In addition, from guaranteeing intensity and suppressing to make the viewpoint of formation of the inclusion (inclusion) of erosion resistance variation, be preferably the scope of 0.5～1.6 quality %, more preferably 0.8～1.4 quality %.
Below the P:0.025 quality %
P is the harmful element that makes the toughness reduction of steel in crystal crystal boundary (crystal grain boundary) segregation (segregate), preferably reduces as much as possible.Particularly, surpass 0.025 quality % if contain P, then toughness significantly reduces, and therefore making P is below the 0.025 quality %.In addition, if be reduced to less than 0.005 quality %, then cause manufacturing cost to rise, what therefore preferably make P is limited to about 0.005 quality % down.
Below the S:0.01 quality %
S combines with Mn and forms non-metallic inclusion (non-metallic inclusion) MnS, and this MnS becomes the starting point of local corrosion, is the harmful element that makes anti-local corrosion reduction.Therefore, preferably reduce as much as possible.Particularly, surpass 0.01 quality %, then cause anti-local corrosion significantly to reduce, therefore make to be limited to 0.01 quality % if contain S.In addition, if reduce S, then cause manufacturing cost to rise, so preferred lower limit is about 0.002 quality % to less than 0.002 quality %.
Al:0.005～0.1 quality %
Al is the element that adds as reductor, adds in the present invention more than the 0.005 quality %.But, surpass 0.1 quality % if add Al, the toughness of steel is reduced, therefore make to be limited to 0.1 quality %.Be preferably the scope of 0.01～0.05 quality %.
N:0.001～0.008 quality %
N is the element that toughness is reduced, and preferably reduces as much as possible.Particularly, if make N content greater than 0.008 quality %, then flexible reduces increase, therefore makes to be limited to 0.008 quality %.But, industrially be difficult to be reduced to less than 0.001 quality %.Therefore, making N is the scope of 0.001～0.008 quality %.
W:0.001～0.5 quality %
W is necessary important element for improving erosion resistance in the present invention.By adding W, the WO that under corrosive environment, forms
4 2-Ion is brought into play barrier action (barrier effect) for negatively charged ion such as chloride ions, and forms insoluble FeWO
4Carry out and suppress corrosive.And the rusty scale that surface of steel plate forms is very fine and close owing to contain W.The interpolation of W suppresses H by such chemistry and physical action
2S and Cl
-The carrying out of the general corrosion of the corrosive environment that exists and the growth (growth of local corrosion) of local corrosion.Therefore, can access the good petroleum tank steel of anti-local corrosion and anti-general corrosion.
And, for the situation that has been coated with the priming paint (zinc rich primer) that contains Zn at steel surface of the present invention, Zn in the priming paint enters in the rusty scale of the densification that contains W, formation is the W at center, the composite oxides of Zn (composite oxides) with Fe, therefore can make Zn continue for a long time to exist at surface of steel plate.Therefore, compare, can suppress the generation of local corrosion for a long time with the steel that do not contain W.
If W is less than 0.001 quality %, then the effect of the raising erosion resistance of above-mentioned W can not fully manifest.On the other hand, if surpass 0.5 quality %, then this effect is saturated, and causes cost to rise.Therefore, in the present invention, making W is the scope of 0.001～0.5 quality %.
More than the Cr:0.06 quality % and less than 0.20 quality %
Cr carries out along with corrosive and is transferred in the rusty scale, blocking-up Cl
-Invade rusty scale, thereby be suppressed at the Cl at the interface of rusty scale and base steel
-Enrichment.In addition, for the situation that has been coated with the priming paint that contains Zn, be the Cr at center, the composite oxides of Zn owing to form with Fe, therefore can make Zn continue for a long time to exist at surface of steel plate.Consequently, compare, can suppress the generation of local corrosion for a long time with the steel that do not contain Cr.But, if being less than 0.06 quality % then can not fully obtain this effect, on the other hand, if more than the 0.20 quality %, then make the toughness of welded zone variation.Therefore, making Cr is that 0.06 quality % is above and less than the scope of 0.20 quality %.
Hot-rolled steel section of the present invention except that above-mentioned basal component, in order to realize the raising of erosion resistance, can also contain a kind or 2 kinds and/or the Mo that is selected among Sn and the Sb in following ranges.
Sn:0.005～0.3 quality %
Sn by with the compound action of W and Cr, improve the acid resistance (acid resistance) of the rusty scale of formed densification, have the effect of the corrosive of inhibition.But,, then can not obtain above-mentioned effect if add less than 0.005 quality %.On the other hand, surpass 0.3 quality %, then cause hot workability (hot workability) and toughness to reduce if add.Therefore, preferably in the scope of 0.005～0.3 quality %, add Sn.
Sb:0.005～0.3 quality %
Sb and Sn are same, improve the acid resistance of the rusty scale of formed densification by the compound action with W and Cr, have the effect of the corrosive of inhibition.But,, then can not obtain above-mentioned effect if add less than 0.005 quality %.On the other hand, surpass 0.3 quality % if add, then above-mentioned effect is saturated, and processibility (workability) is reduced.Therefore, preferably in the scope of 0.005～0.3 quality %, add Sb.
Mo:0.001～0.5 quality %
Mo makes anti-general corrosion and anti-local corrosion raising with W, when Cr adds.And, since with the compound action of W, Cr and Sn and/or Sb, promote the formation of fine and close rusty scale, and then have the effect that improves erosion resistance.Above-mentioned effect obtains more than adding 0.001 quality %.But if greater than 0.5 quality %, then this effect is saturated, and causes cost to rise.Therefore, when adding Mo, be preferably the scope of 0.001～0.5 quality %.
Hot-rolled steel section of the present invention is a purpose to improve hardness of steel on the basis of mentioned component, can also in following ranges, add be selected among Nb, V, Ti and the B more than a kind or 2 kinds.
Nb:0.001～0.1 quality %
Nb is the element that adds for the intensity that improves steel.If then its effect is little less than 0.001 quality %.On the other hand, if greater than 0.1 quality %, then toughness reduces.Preferably be the scope of 0.001～0.1 quality % when therefore, adding Nb.
V:0.002～0.1 quality %
V is the element that adds for the intensity that improves steel.If then improve the effect of intensity less than 0.002 quality % little.On the other hand, if greater than 0.1 quality %, then toughness reduces.Preferably be the scope of 0.002～0.1 quality % when therefore, adding V.
Ti:0.001～0.1 quality %
Ti is for the intensity that improves steel and toughness and the element that adds.If it is little less than the then above-mentioned effect of 0.001 quality %.On the other hand, if greater than 0.1 quality %, then this effect is saturated.Preferably be the scope of 0.001～0.1 quality % when therefore, adding Ti.
Below the B:0.01 quality %
B is the element that adds for the intensity that improves steel.But, cross 0.01 quality % if add B ultrasonic, then toughness reduces.Therefore, when adding B, preferably be below the 0.01 quality %.When adding B, preferably add more than 0.0003% with above-mentioned purpose.
Hot-rolled steel section of the present invention on the basis of mentioned component, in order to improve ductility (ductility) and toughness, can contain a kind or 2 kinds that is selected among Ca and the REM in following ranges.
Ca:0.0002～0.005 quality %
Ca has ductility and the flexible effect that the morphology Control (Shape control of inclusions) by inclusion improves steel.But, if then this effect is little less than 0.0002 quality % for the content of Ca.On the other hand, then cause toughness to reduce if surpass 0.005 quality %.Therefore, when adding Ca, preferably be the scope of 0.0002～0.005 quality %.
REM:0.0005～0.015 quality %
REM has the effect that makes ductility and toughness raising by the morphology Control of inclusion.But then this effect is little less than 0.0005 quality % as if REM.On the other hand, if surpass then toughness reduction of 0.015 quality %.Therefore, when adding REM, be preferably the scope of 0.0005～0.015 quality %.
In addition, the combination of particularly preferred selection element is Sn and Sb and W.
Hot-rolled steel section of the present invention, the surplus except that mentioned component are Fe and unavoidable impurities.But, as long as in the scope of not damaging action effect of the present invention, then do not refuse to contain the composition outside above-mentioned.For example, if O is that 0.008 quality % is following, Cu is that 0.05 quality % is following, Ni is below the 0.05 quality %, then can allow.
Cu helps to improve anti-general corrosion in containing the environment of hydrogen sulfide.But the effect that improves anti-local corrosion is limited.And interpolation Cu causes the remarkable reduction of hot workability.Therefore do not add Cu in the present invention energetically.But can contain below the 0.05 quality % as unavoidable impurities.
And, thinks that Ni does not have the effect that improves anti-general corrosion and anti-local corrosion, and only become the reason that cost rises, so steel of the present invention does not add Ni energetically.But can contain below the 0.05 quality % as unavoidable impurities.
(microstructure)
Then, the microstructure that should have the hot-rolled shape steel for crude oil tanks of excellent corrosion resistance under high strength of the present invention describes.
Shipping steel plate, particularly yielding stress YP are the above high-strength steel plate of 315MPa, usually, by using carbon equivalent (carbon equivalent) is controlled at the former material of steel that lower level has been given high weldability, employing combines the TMCP of controlled rolling (controlled rolling) and controlled chilling (controlled cooling), the bainite (bainite) that imports hard in the steel plate tissue is as the 2nd phase (second phase), thus the realization high strength.Then, for the situation that requires low-temperature flexibility (roughness of low temperature), require the situation of wall thickening, by the condition optimization of above-mentioned controlled rolling and controlled chilling is dealt with.Therefore, the microstructure of steel plate is generally ferrite+bainite structure at this moment.
On the other hand, for the situation of hot-rolled steel section, the minor face situation different with width, the thickness on long limit is more, and for example the cross section is not the situation of orthogonal angle of unequal legs ﹠ thickness, inevitablely produces the inhomogeneous of temperature when rolling, during cooling.Particularly, owing to using controlled chilling (acceleration cooling: during intensity accelerated cooling) is adjusted, unrelieved stress (residual stress) becomes inhomogeneous, bring out and reverse (twist), crooked (bend), warpage (curvature), cause dimensional precision to reduce, so the load of the shape correction after rolling increase.Therefore, the bainite that is difficult to import hard as second mutually and the method for high strength is applied to hot-rolled steel section.This is for other all hot-rolled steel sections such as T-steels.
Therefore, the cooling of the acceleration after hot-rolled shape steel for crude oil tanks requires not to be rolled and realize high strength more than the yielding stress YP:315MPa, more than the preferred tensile strength TS:440MPa.To achieve these goals, need realize high strength by ferrite+pearlitic structure as common hot rolling microstructure.As the method that realizes high strength by ferrite+pearlitic structure, can consider: increase the 2nd phase the percentile method of perlite, make ferritic structure grain refined (grain refining) method, make ferrite solution strengthening (solid solutionstrengthening) or precipitation strength (precipitation hardening) and the method for hardening or in that (γ+α) two-phase region is rolled and makes the part ferrite to become the ferritic method of processing etc.
In the aforesaid method, be effective means for YP is risen,, therefore only can not realize sufficient high strength by this method because the rising of TS is little though make the method for ferrite grain refined.And, increase the percentile method of perlite, need add C in large quantities.But, if excessively add C, then cause the reduction of weldability, therefore not preferred.And, add solution strengthening element or precipitation strength element and method that ferrite is strengthened, owing to add a large amount of alloying elements, therefore cause the reduction of weldability or cause the rising of former material cost.
On the other hand, applying flexibly the ferritic method of processing can be suppressed at inferior limit and keep YP and TS are risen in the interpolation with C and alloying element.And, realize high strength owing to utilizing the ferritic method of processing can after hot rolling, not carry out controlled chilling (quickening cooling), when bending, the warpage during rolling, the cooling of peculiar problem that therefore can be when suppressing to make as shaped steel takes place, the realization high strength.Therefore, in the present invention, as the high strength method of hot-rolled shape steel for crude oil tanks, adopting and making the microstructure of steel is to contain the method for processing ferritic ferrite+pearlitic structure.
Above-mentioned processing ferrite need be counted more than 10% of structure of steel integral body with area occupation ratio.If the processing ferrite then can not obtain the reinforcement of steel fully less than 10%.In addition, though the upper limit does not stipulate especially that if surpass 70%, then intensity rises saturated.And, along with (load of α+when γ) two-phase region is rolling increases, and the risk of roller rhegma increases, and therefore preferably making the ferritic area occupation ratio of processing is below 70%.
Here, above-mentioned processing ferrite is meant by at Ar
3(hot rolling of the two-phase region of α+γ) and the high ferrite of dislocation desity that is rolled that transformation temperature is following.Process ferritic percentage and be by describing the processing ferrite of flattening, its area shared in microstructure of image analysis and quantification, and measure its percentage and obtain.Thickness of slab 1/4 part at the thickest position of preferred thickness of slab that locates of microstructure.
Surplus is ferrite (except that the processing ferrite) and pearlitic structure.Pearlitic structure is preferably below 20% in area occupation ratio.In addition, the tissue outside ferrite/perlite, for example bainite etc. exist below 20% also passable in area occupation ratio.
(manufacture method)
Then, the method that manufacturing is had a hot-rolled shape steel for crude oil tanks that contains the ferritic ferrite+pearlitic structure of above-mentioned processing describes.
When making hot-rolled shape steel for crude oil tanks of the present invention, preferably, at first, to have the steel melting that mentioned component is formed by converter (converter), electric furnace (electrical furnace) etc. with generally well-known method, make steel billet (slab), bloom (bloom), the little square billet former materials of steel such as (billet) by continuous metal cast process (continuous casting), ingot casting method generally well-known methods such as (ingotcasting) again.In addition, also can after melting, implement ladle refining (ladle refining), vacuum outgas processing such as (vacuum degassing).
Then, with the former material of above-mentioned steel pack into heat in the process furnace after, hot rolling make have desired size, desired microstructure and the hot-rolled shape steel for crude oil tanks of mechanical characteristics (mechanical properties).
At this moment, making the Heating temperature of the former material of steel is 1000～1350 ℃ scope.If Heating temperature is lower than 1000 ℃ of then resistance to deformation increases, it is difficult that hot rolling becomes.On the other hand, if heating is higher than 1350 ℃, then become the generation reason of surface spots, perhaps oxidization burning loss (scale loss), units of fuel consumption increase.Be preferably 1100～1300 ℃ scope.
Ensuing hot rolling need make Ar
3The following rolling rate of accumulation of transformation temperature is 10～80%.If rolling temperature is higher than Ar
3Transformation temperature, then the microstructure of steel does not contain the processing ferrite, can not guarantee necessary strength and toughness.Similarly, if Ar
3The rolling rate of accumulation below the transformation temperature is less than 10%, and then because the ferritic growing amount of processing is few, so the highly malleablized effect is little.Otherwise, surpassing 80% rolling rate if reach, then rolling load increases and the rolling difficulty that becomes, and perhaps rolling road number of times increases and causes productivity to reduce.Therefore, make Ar
3The following rolling rate of accumulation of transformation temperature is 10～80%.Be preferably 10～60% scope.In addition, Ar
3Following rolling the carrying out at least of transformation temperature gets final product more than 1 passage, also can be multi-pass.
Here, Ar
3The following rolling rate of accumulation of transformation temperature is meant that the sectional area of the rolling stock after the rolling end (B) is with respect to Ar
3The relative reduction in area of the sectional area of the rolling stock under the transformation temperature (A) (reduction of area) is represented with following formula.
(Ar
3The rolling rate of accumulation [%] that transformation temperature is following)=100 * (A-B)/A
And above-mentioned hot rolling need be (Ar making rolling end temp
3Transformation temperature-30 ℃)～(Ar
3Transformation temperature-180 ℃) carries out under the condition.If rolling end temp surpasses (Ar
3Transformation temperature-30 ℃), then can not obtain the highly malleablized effect that produces by utilizing the high ferritic importing of processing of the rolling dislocation desity of two-phase region fully.On the other hand, if be lower than (Ar
3Transformation temperature-180 ℃), then rolling load increases because resistance to deformation increases, the rolling difficulty that becomes.
And above-mentioned hot rolling is preferably before rolling below carrying out the Ar3 transformation temperature, and making the temperature head (being the temperature head of the former material integral body of rolling hot-rolled steel section midway) between each position (long limit, minor face, web, the edge of a wing etc.) of rolling shaped steel midway in advance is in 50 ℃.For example,, preferably compare, the thick short brink of wall thickness carried out water-cooled, the temperature head of long side and short brink is suppressed in 50 ℃ in the front and back of milling train with the long side of wall thickness for long limit and the different angle of unequal legs ﹠ thickness of minor face place wall thickness.If temperature head is higher than 50 ℃, the then not only deviation of the intensity of short brink and long side, property of toughness increase, and the bending in the refrigerating work procedure after rolling, warpage increase, and correct needed burden and increase, and productivity is reduced.In addition, the temperature head at each position of shaped steel is with the surface temperature at each position (edge of a wing, web etc.) of the sectional position much at one (extension position) of the rolling shaped steel midway of radiation thermometer mensuration, obtains according to differing from of resulting top temperature and minimum temperature.
(for example, short brink and long side) temperature head is suppressed at 50 ℃ with interior method, the preferred method of controlling at the cooling apparatus of the front and back of roughing mill (rougher rolling mill) setting of using as each position with shaped steel.Particularly, preferably by above-mentioned cooling apparatus, emphasis carries out water-cooled to the thick short brink of wall thickness and eliminates the method for temperature head.The water-cooled of this moment can be only before and after milling train the front, only carry out in the back or in the both sides, front and back, and, can carry out several times according to size, the precision prescribed of rolling shaped steel.In addition, the discharge density during preferred water-cooled is 1m
3/ m
2More than the min.
That carries out after the hot rolling is cooled to air cooling (putting cold).Thus, can reduce by the inhomogeneous cooling after rolling and spare and the such change of shape of bending, warpage of generation, can alleviate the corrigent burden of the product after rolling.Put the speed of cooling speed when cold, different and different according to thickness of slab, be about 0.4 ℃/s～about 1.0 ℃/s.The processing (forcing cooling/insulation etc.) of in the scope of above-mentioned speed of cooling, cooling implement being quickened and being slowed down, in fact with put cold identically, so especially it is not foreclosed.
When the hot-rolled steel section of the present invention that as above obtains uses as hot-rolled shape steel for crude oil tanks, contain the priming paint of Zn, can improve anti-local corrosion and anti-general corrosion significantly by coating.Generally, coating prime lacquer after sandblasting is implemented on the surface of steel.In order to cover the whole surface of steel equably, need film more than certain thickness, in order to improve anti-local corrosion and anti-general corrosion, the coating thickness that preferably makes the priming paint that contains Zn is more than the 5 μ m.In addition, though from improving the viewpoint of anti-local corrosion and anti-general corrosion, the upper limit of glue spread is blocked up as if priming paint without limits, and then therefore cutting, weldability and economy variation preferably make and be limited to about 100 μ m.More preferably coating thickness is more than the 15 μ m.The kind of zinc rich primer is not limit, and can use known product.About filming of other, also can freely add according to purpose, but in the application of the preferred zinc rich primer individual layer of economic aspect.
Embodiment
(embodiment 1)
Have the steel that becomes to be grouped into shown in table 1-1, the 1-2 by vacuum melting furnace or converter melting, make bloom.With this bloom process furnace of packing into, and after being heated to the temperature shown in table 2-1, the 2-2, under the table condition that 3-1,3-2 put down in writing, carry out hot rolling, make the angle of unequal legs ﹠ thickness (NAB) and the rolling T-steel of sectional dimension shown in table 2-1, the 2-2.In addition, in table 2-1,2-2, about angle of unequal legs ﹠ thickness (NAB), with long side as web (web), represent as the edge of a wing (flange) with short brink.
Cut JIS1A tension test sheet from the short brink of angle of unequal legs ﹠ thickness, the edge of a wing of T-steel, measure tensile properties (yielding stress YP, tensile strength TS, elongation El).And; input heat by 20kJ/cm carries out gas metal-arc welding (GMAW) to the short brink of angle of unequal legs ﹠ thickness, the edge of a wing of T-steel; cut Charpy impact test sheet (2mmV v notch v test film) from its HAZ central part; for the Charpy impact test under-20 ℃, measure the absorption energy.And, cut the sample that structure observation is used from the short brink of angle of unequal legs ﹠ thickness, the edge of a wing of T-steel, under 200 times multiplying power, observe the tissue of thickness of slab 1/4 part by microscope.Describe processing ferrite in the viewed tissue, that pass through the flattening of the rolling generation of two-phase region,, obtain the area occupation ratio that the processing ferrite is occupied in microstructure by above-mentioned method.In addition, in having processing ferritic steel (except that rolling No.1E), main outside the processing ferrite is the non-processing ferrite of generation after perlite (except that rolling No.1G) or bainite (rolling No.1G) and the hot rolling end mutually.In addition, in the example of the present invention, perlite exists 3～20% in area occupation ratio.
Table 1-1
Table 1-2
Table 2-1
Table 2-2
Table 3-1
* 1.Ar
3The rolling rate of accumulation that transformation temperature is following
Table 3-2
* 1Ar
3The rolling rate of accumulation that transformation temperature is following
Table 4-1,4-2 show the result of above-mentioned tension test, Charpy impact test and microstructure investigation.From table 4-1,4-2 as can be known, have one-tenth according to the invention and be grouped into hot-rolled steel section with microstructure, particularly, can access more than the above YP:315MPa of the desired intensity of the present invention, more than the TS:440MPa by containing the shaped steel that the ferritic ferrite of processing+pearlitic microstructure constitutes that is organized as more than 10% with respect to whole.And these shaped steel, mother metal and weld part all demonstrate the shock absorption energy more than the 34J under-20 ℃, so impact characteristics is also good.
Relative therewith, satisfy that one-tenth of the present invention is grouped into and microstructure is ferrite+perlite, but do not contain processing ferritic shaped steel (rolling No.1E) or process the low shaped steel of ferritic percentage (rolling No.1F), can not guarantee the desired intensity of the present invention (more than the YP:315MPa, more than the TS:440MPa).
In addition we know, satisfying one-tenth of the present invention is grouped into, but making microstructure by water-cooled acceleration cooling after the hot rolling is the shaped steel (rolling No.1G) of ferrite+bainite, though be high strength, but, be difficult to carry out operation production by the change of shape of reversing, warpage, bending etc. cause big (not record in the table).And, carry out Ar
3Surface temperature difference during the following hot rolling of transformation temperature is higher than 50 ℃ rolling No.1I, though mechanical characteristics is no problem, and shaped steel generation warpage, bending.
Table 4-1
* 1F: ferrite, F
SH: contain the ferritic ferrite of processing, P: perlite, B: bainite
Table 4-2
* 1F: ferrite, F
SH: contain the ferritic ferrite of processing, P: perlite, B: bainite
And each hot-rolled steel section for making cuts out the foursquare small pieces of thick 10mm * wide 50mm * long 50mm from the short brink of angle of unequal legs ﹠ thickness, the edge of a wing of T-steel, and implements sandblasting on its surface.Then, the coating thickness that makes mineral-type (inorganic-based) zinc rich primer respectively is 4 other coatings of level of 0 μ m (not having coating), 5～10 μ m, 15～25 μ m, 50～70 μ m, makes test film.Then, cover the end face and the internal surface of above-mentioned test film, only, make the corrosion test sheet above by the test face, being coated with the greasy filth of gathering from the oil tanker of reality that contains oil composition (sludge) equably with the coating of non-corrosibility.
And above-mentioned corrosion test sheet is made 2 kinds of different test films of condition of surface.One is the test film (test film 1) that has been coated with greasy filth on quilt test face equably.Another is the test film (test film 2) that only is coated with greasy filth partly being coated with the sulphur mixing greasy filth of the sulphur that has mixed 50 quality % in the greasy filth by the central part 2mm Φ of test face in other parts equably.In this test film 2, sulphur mixing greasy filth becomes the starting point of local corrosion, promotes corrosion, therefore can grasp steel product ingredient, priming paint and their combination by the test-results of this test film 2 and give the inhibition influence that local corrosion is brought.And, can learn that by contriver's result of study compare with the test of use-testing sheet 1, the dependency of the corrosion test of use-testing sheet 2 and the exposure test of true ship is higher.
Then, these test films are supplied 1 month corrosion test of dipping in experimental liquid 6 at corrosion testing apparatus shown in Figure 1.This corrosion testing apparatus is the bilayer device of corrosion test groove 2, thermostatic bath 3, packs into the experimental liquid 6 of the local corrosion identical with the local corrosion that takes place on the actual petroleum tank base plate can take place in corrosion test groove 2.That is, above-mentioned experimental liquid 6 uses the following liquid that obtains: the artificial seawater with the ASTMD1141 regulation is the test mother liquor, imports in this liquid and is adjusted to 5 volume %O by intrinsic standoff ratio
2+ 10 volume %H
2S, surplus N
2The mixed gas that constitutes (importing gas 4).And the temperature by the temperature of regulating the water 7 that injects in the thermostatic bath 3 with experimental liquid 6 remains on 50 ℃.In addition, experimental liquid 6 is in the state that is stirred owing to supply with importing gas 4 continuously always.Among Fig. 1,5 expressions expellant gas from Thoughs.
After the above-mentioned corrosion test, remove the rust that test film surface generates, the visual observation etch state, and with the depth of corrosion of drift indicator (dip meter) mensuration local corrosion generating unit, according to the grade of the following anti-local corrosion of criteria.
＜anti-local corrosion grade 〉
1: no local corrosion
2: local erosion depth spot is less than 0.1mm
3: local erosion depth spot is more than the 0.1mm and less than 0.2mm
4: local erosion depth spot is more than the 0.2mm and less than 0.6mm
5: local erosion depth spot is more than the 0.6mm and less than 1.0mm
6: local erosion depth spot is more than the 1.0mm and less than 1.5mm
7: local erosion depth spot is more than the 1.5mm
The results are shown in of above-mentioned local corrosion test shown 5-1,5-2.In the test of use-testing sheet 1, all be 1～3 grade to have steel No.1～26 that one-tenth according to the invention is grouped into for the evaluation of the anti-local corrosion of the hot-rolled steel section of former material, local erosion depth spot is suppressed in less than 0.2mm.Particularly, be coated with the shaped steel of the zinc rich primer more than the 5 μ m, the evaluation of anti-local corrosion is 1 grade, has suppressed the generation of local corrosion effectively.On the other hand, be the hot-rolled steel section of former material to depart from steel No.27～33 that one-tenth of the present invention is grouped into, except that the shaped steel of No.32, anti-local corrosion is all poor than hot-rolled steel section of the present invention.
And, in the test of use-testing sheet 2, obtain having promoted more the result of the carrying out of local corrosion than the situation of use-testing sheet 1, can be expressly understood that the difference between steel grade under difference, particularly the zinc rich primer coating state between steel grade.That is, be the anti-local corrosion of the hot-rolled steel section of former material with steel No.1～26 of example, under any one state of no zinc rich primer coating state, zinc rich primer coating state, all be better than being the hot-rolled steel section of former material with steel No.27～33 of comparative example.It should be noted that, though with the steel No.32 of comparative example is that the hot-rolled steel section of former material demonstrates the anti-local corrosion with the present invention's example par in the test of use-testing sheet 1, but anti-local corrosion is obviously poor than the present invention's example in the test of use-testing sheet 2, and this difference becomes remarkable.
As can be known from the above results, the anti-local corrosion of hot-rolled steel section according to the invention is good.
Table 5-1
Table 5-2
(embodiment 2)
From cutting out the orthogonal small pieces of thick 4mm * wide 25mm * long 48mm for the hot-rolled steel section of former material, implement sandblasting in its surface with steel No.1～33 identical with the steel that uses the embodiment 1.The coating thickness that makes the mineral-type zinc rich primer then respectively is the coating of 0 μ m (not having coating), 5～10 μ m, 15～25 μ m, 50～70 μ m, makes 4 kinds of corrosion test sheets.Then, for accelerated corrosion test, to the score that above-mentioned film coated surface is given the X font that reaches steel surface, making damaged area rate (scratch area rate) is 1.0%, for testing in following general corrosion.
Corrosion testing apparatus shown in Figure 2 is used in the general corrosion test.This corrosion testing apparatus is made of corrosion test groove 9 and temperature control panel 10, and injection remains on temperature in 40 ℃ water 13 in corrosion test groove 9.And, by in above-mentioned water 13, importing CO by 12 volume %
2, 5 volume % O
2, 0.01 volume % SO
2, 0.1 volume % H
2S, surplus N
2The mixed gas that constitutes (importing gas 11) makes supersaturation water steam be full of corrosion test groove 9, reproduces the corrosive environment of petroleum tank upperdeck the inside.And, the temperature control panel 10 of well heater and refrigerating unit is housed by inside, to the corrosion test sheet 8 inside the top that is placed on this Thoughs, giving with 30 ℃ * 4 hours+50 ℃ * 4 hours repeatedly is 1 round-robin temperature variation 20 days, make the test film surface generate dew, cause general corrosion thus.Among Fig. 2,12 expressions are from the Thoughs expellant gas.
After the above-mentioned test, following anti-general corrosion to each test film is estimated.
The material of＜no zinc rich primer coating 〉
By the quality change before and after the experiment, obtain the thickness of slab reduction (decreasein plate thickness) that causes by corrosion, it is scaled annual corrosion thickness of slab, according to following grade classification anti-general corrosion is estimated.
1: corrosion speed is less than 0.10mm/
2: more than the corrosion speed 0.10mm/ and less than 0.25mm/
3: more than the corrosion speed 0.25mm/ and less than 0.50mm/
4: more than the corrosion speed 0.50mm/ and less than 1.00mm/
5: more than the corrosion speed 1.00mm/
The material of＜coating zinc rich primer 〉
Measure the area occupation ratio of the rust of the surface of each test film and the generation of filming down, anti-general corrosion is estimated according to following grade classification.
1: the rust area occupation ratio is less than 5%
2: the rust area occupation ratio is more than 5% and less than 15%
3: the rust area occupation ratio is more than 15% and less than 25%
4: the rust area occupation ratio is more than 25% and less than 50%
5: the rust area occupation ratio is more than 50%
The result of above-mentioned general corrosion test together is shown among table 5-1, the 5-2.According to table 5-1,5-2, steel No.1～26 that are grouped into one-tenth according to the invention are the hot-rolled steel section of former material, and the anti-general corrosion of no coating material is 1～2 grade, for well.Relative therewith, steel No.27～33 with comparative example are the anti-general corrosion of the hot-rolled steel section of former material as can be known, not only poor than the hot-rolled steel section of example under the situation that does not have the coating of mineral-type zinc rich primer, and also poor under the situation of coating than the hot-rolled steel section of example.
Utilize possibility on the industry
According to the present invention, also bring into play good anti-general corrosion and the hot-rolled steel section of anti-local corrosion even can provide at an easy rate under high strength and naked state and primer coating state. Therefore, for the situation that hot-rolled steel section of the present invention is used as vertical material of petroleum tank etc., owing to can significantly alleviate the general corrosion of petroleum tank top (upper deck and side plate), the local corrosion of petroleum tank base plate, therefore the time of Repair Coatings can be extended to, and then repairing work, reduction repairing cost can be realized alleviating.
Because hot-rolled shape steel for crude oil tanks of the present invention demonstrates good corrosion resistance under the corrosive environment that is caused by seawater, therefore also be effectively aspect the life-span that prolongs boats and ships itself by the repairing time that prolongs boats and ships, the hot-rolled steel section that use in other field that also can be used for using under similar corrosive environment.
Claims (13)
1. a hot-rolled shape steel for crude oil tanks is characterized in that,
Having following one-tenth is grouped into: contain that C:0.001～0.16 quality %, Si:0.01～1.5 quality %, Mn:0.1～2.5 quality %, P:0.025 quality % are following, S:0.01 quality % following, Al:0.005～0.1 quality %, N:0.001～0.008 quality %, W:0.001～0.5 quality % and Cr:0.06 quality % is above and less than 0.20 quality %, perhaps also contain any at least a group in following A～D group, surplus is made of Fe and unavoidable impurities
The A group: be selected from a kind or 2 kinds among Sn:0.005～0.3 quality % and Sb:0.005～0.3 quality %,
The B group: Mo:0.001～0.5 quality %,
C group: during Nb:0.001～0.1 quality %, V:0.002～0.1 quality %, Ti:0.001～0.1 quality % and B:0.01 quality % are following more than a kind or 2 kinds,
The D group: be selected from a kind or 2 kinds among Ca:0.0002～0.005 quality % and REM:0.0005～0.015 quality %,
Have the microstructure that is made of ferrite and perlite, described ferrite contains with respect to whole tissue counts processing ferrite more than 10% with area occupation ratio.
2. hot-rolled shape steel for crude oil tanks as claimed in claim 1 is characterized in that, contains a kind or 2 kinds that is selected among Sn:0.005～0.3 quality % and the Sb:0.005～0.3 quality %.
3. hot-rolled shape steel for crude oil tanks as claimed in claim 1 is characterized in that, contains Mo:0.001～0.5 quality %.
4. hot-rolled shape steel for crude oil tanks as claimed in claim 2 is characterized in that, contains Mo:0.001～0.5 quality %.
5. hot-rolled shape steel for crude oil tanks as claimed in claim 1 is characterized in that, contain be selected from Nb:0.001～0.1 quality %, V:0.002～0.1 quality %, Ti:0.001～0.1 quality % and B:0.01 quality % in following more than a kind or 2 kinds.
6. hot-rolled shape steel for crude oil tanks as claimed in claim 2 is characterized in that, contain be selected from Nb:0.001～0.1 quality %, V:0.002～0.1 quality %, Ti:0.001～0.1 quality % and B:0.01 quality % in following more than a kind or 2 kinds.
7. hot-rolled shape steel for crude oil tanks as claimed in claim 3 is characterized in that, contain be selected from Nb:0.001～0.1 quality %, V:0.002～0.1 quality %, Ti:0.001～0.1 quality % and B:0.01 quality % in following more than a kind or 2 kinds.
8. hot-rolled shape steel for crude oil tanks as claimed in claim 4 is characterized in that, contain be selected from Nb:0.001～0.1 quality %, V:0.002～0.1 quality %, Ti:0.001～0.1 quality % and B:0.01 quality % in following more than a kind or 2 kinds.
9. as each described hot-rolled shape steel for crude oil tanks in the claim 1～8, it is characterized in that, contain a kind or 2 kinds that is selected among Ca:0.0002～0.005 quality % and the REM:0.0005～0.015 quality %.
10. as each described hot-rolled shape steel for crude oil tanks in the claim 1～8, it is characterized in that having yielding stress is that 315MPa is above, tensile strength is the above intensity of 440MPa.
11. hot-rolled shape steel for crude oil tanks as claimed in claim 9 is characterized in that, having yielding stress is that 315MPa is above, tensile strength is the above intensity of 440MPa.
12. the manufacture method of a hot-rolled shape steel for crude oil tanks will have after each described one-tenth is grouped in the claim 1～9 the former material of steel is heated to 1000～1350 ℃, carry out hot rolling and make shaped steel, it is characterized in that,
Make Ar
3The following rolling rate of accumulation of transformation temperature is 10～80%, rolling end temp is (Ar
3Transformation temperature-30 ℃)～(Ar
3Transformation temperature-180 ℃) implements described hot rolling under the condition, put cold then.
13. the manufacture method of hot-rolled shape steel for crude oil tanks as claimed in claim 12 is characterized in that, in described hot rolling, the temperature head of different sites that makes rolling shaped steel midway in 50 ℃, is implemented Ar in the surface temperature difference then
3The following rolling rate of accumulation of transformation temperature is 10～80%, rolling end temp is (Ar
3Transformation temperature-30 ℃)～(Ar
3Transformation temperature-180 ℃) described hot rolling.
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| JP2007246844 | 2007-09-25 | ||
| JP2007-246844 | 2007-09-25 | ||
| JP2008236029A JP5320919B2 (en) | 2007-09-25 | 2008-09-16 | Hot rolled shape steel for crude oil tank and method for producing the same |
| JP2008-236029 | 2008-09-16 | ||
| PCT/JP2008/067780 WO2009041703A1 (en) | 2007-09-25 | 2008-09-24 | Hot-rolled shape steel for crude oil tanks and process for manufacturing the same |
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| JP (1) | JP5320919B2 (en) |
| KR (2) | KR20130006546A (en) |
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| JP5145897B2 (en) * | 2007-11-22 | 2013-02-20 | 新日鐵住金株式会社 | Corrosion resistant steel for cargo oil tanks |
| JP2011231365A (en) * | 2010-04-27 | 2011-11-17 | Jfe Steel Corp | Hot rolled shape steel for vessel and method of manufacturing the same |
| CN102851582B (en) * | 2011-06-28 | 2016-01-20 | 鞍钢股份有限公司 | A kind of sour crude oil accumulating tank corrosion-resistant steel and manufacture method thereof |
| JP5942480B2 (en) * | 2012-03-01 | 2016-06-29 | Ｊｆｅスチール株式会社 | Steel for construction and civil engineering structures with excellent compatibility with water-based paints |
| CN104411848B (en) * | 2012-06-27 | 2017-05-31 | 杰富意钢铁株式会社 | Tufftride treatment steel plate and its manufacture method |
| CN103014496B (en) * | 2012-12-06 | 2014-12-03 | 武汉钢铁(集团)公司 | High-strength hot-rolled steel strip with thickness ranging from 1.1 to 2 mm and easy to form |
| JP2017190522A (en) * | 2016-04-11 | 2017-10-19 | Ｊｆｅスチール株式会社 | Steel material |
| JP6690585B2 (en) * | 2017-03-14 | 2020-04-28 | Ｊｆｅスチール株式会社 | Steel material and manufacturing method thereof |
| CN114574766B (en) * | 2022-03-04 | 2023-04-11 | 武安市裕华钢铁有限公司 | Ni-RE series corrosion-resistant low-carbon hot-rolled steel strip and production process thereof |
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| JP3860666B2 (en) * | 1998-07-03 | 2006-12-20 | 新日本製鐵株式会社 | Corrosion resistant steel for cargo oil tanks |
| JP2001107180A (en) * | 1999-10-13 | 2001-04-17 | Nkk Corp | Corrosion resistant steel for oil loading tank |
| JP4483107B2 (en) * | 2001-03-09 | 2010-06-16 | Ｊｆｅスチール株式会社 | Marine steel with excellent coating life |
| JP3753088B2 (en) * | 2001-07-04 | 2006-03-08 | 住友金属工業株式会社 | Steel material for cargo oil tanks |
| WO2003087414A1 (en) * | 2002-03-29 | 2003-10-23 | Nippon Steel Corporation | High tensile steel excellent in high temperature strength and method for production thereof |
| JP4267367B2 (en) * | 2002-06-19 | 2009-05-27 | 新日本製鐵株式会社 | Crude oil tank steel and its manufacturing method, crude oil tank and its anticorrosion method |
| CN1946864A (en) * | 2004-04-14 | 2007-04-11 | 住友金属工业株式会社 | Steel product for cargo oil tank |
| JP4449691B2 (en) * | 2004-04-14 | 2010-04-14 | 住友金属工業株式会社 | Steel material for cargo oil tanks |
| WO2007097142A1 (en) * | 2006-02-27 | 2007-08-30 | Jfe Steel Corporation | Corrosion-resistant steel material for ship and vessel |
| KR101023634B1 (en) * | 2006-03-30 | 2011-03-22 | 제이에프이 스틸 가부시키가이샤 | Corroson-resistant steel material for crude oil storage tank, and crude oil storage tank |
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| JP5320919B2 (en) | 2013-10-23 |
| TW200925294A (en) | 2009-06-16 |
| KR20100023049A (en) | 2010-03-03 |
| JP2009097083A (en) | 2009-05-07 |
| TWI460285B (en) | 2014-11-11 |
| KR101241932B1 (en) | 2013-03-11 |
| KR20130006546A (en) | 2013-01-16 |
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