CN102933732A - Structural stainless steel sheet having excellent corrosion resistance at weld and method for manufacturing same - Google Patents
Structural stainless steel sheet having excellent corrosion resistance at weld and method for manufacturing same Download PDFInfo
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
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- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B9/00—Measures for carrying out rolling operations under special conditions, e.g. in vacuum or inert atmosphere to prevent oxidation of work; Special measures for removing fumes from rolling mills
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- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
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- C21D6/005—Heat treatment of ferrous alloys containing Mn
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- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
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- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
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- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/001—Ferrous alloys, e.g. steel alloys containing N
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- C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
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- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
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- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
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- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
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- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
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- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/46—Ferrous alloys, e.g. steel alloys containing chromium with nickel with vanadium
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/50—Ferrous alloys, e.g. steel alloys containing chromium with nickel with titanium or zirconium
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/58—Ferrous alloys, e.g. steel alloys containing chromium with nickel with more than 1.5% by weight of manganese
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Abstract
isclosed are: a structural stainless steel sheet which can be highly efficiently produced at low cost and has excellent corrosion resistance in a welded part; and a method for producing the structural stainless steel sheet. Specifically disclosed is a structural stainless steel sheet which contains, in mass%, 0.01-0.03% of C, 0.01-0.03% of N, 0.01-0.40% of Si, 1.5-2.5% of Mn, 0.04% or less of P, 0.02% or less of S, 0.05-0.15% of Al, 10-13% of Cr, 0.5-1.0% of Ni, and 4 (C + N) or more but 0.3% or less of Ti, while controlling V to 0.05% or less, Ca to 0.0030% or less and O to 0.0080% or less. The structural stainless steel sheet is further characterized in that the F value obtained by Cr + 2 Si + 4 Ti - 2 Ni - Mn - 30 (C + N) is 11 or less, the FFV value obtained by Cr + 3 Si + 16 Ti + Mo + 2 Al - 2 Mn - 4 (Ni + Cu) - 40 (C + N) + 20 V is 9.0 or less, and the balance of the structural stainless steel sheet is made up of Fe and unavoidable impurities.
Description
Technical field
The present invention relates to be suitable for as transporting for example excellent structure stainless steel plate (structural stainlesssteel sheet) and the manufacture method thereof of vehicle body purposes erosion resistance material, weld part (corrosion resistance) of the lorry of coal (coal), iron ore (iron ore) (railway freight-car (railway wagon)).
Background technology
The vehicle body purposes material of the lorry of carry coal, iron ore (railway freight-car) uses stainless steel more.Owing to contained in a large number sulphur composition (sulfur content) by unearthed coal, so the vehicle body of railway freight-car material requirements corrosion resistance to sulfuric acid (sulfate corrosion resistance), the particularly intergranular corrosion resistance of weld part (intergranular corrosion resistance) used.
As the stainless steel that has erosion resistance and weldability concurrently, the ferrite-group stainless steel that contains Ti of the tenacity excellent of weld part is for example disclosed in the patent documentation 1.But, in the technology of patent documentation 1, so that becoming ferritic phase, the tissue of weld part carries out Composition Design (ferrite phase), therefore there be toughness (toughness), erosion resistance and insufficient this problem of weld part.
To this, following technology being disclosed in the patent documentation 2,3: by the phase fraction under the control high temperature, thereby generates an amount of martensitic phase (martensitic phase) at weld part, improve processibility (workability), the erosion resistance of weld part.The stainless steel of the welding process that is suitable for using carbon dioxide (carbon dioxide gas) is disclosed in the patent documentation 4 in addition.In addition, the people among the inventor has proposed a kind of structure stainless steel plate, wherein, but at first uses the parameter (parameter) of the tissue of correct Prediction weld part, one-tenth is grouped into rationalization, thereby has improved the erosion resistance (patent documentation 5) of weld part.
Patent documentation 1: Japanese kokai publication hei 3-249150 communique
Patent documentation 2: TOHKEMY 2002-167653 communique
Patent documentation 3: TOHKEMY 2009-13431 communique
Patent documentation 4: TOHKEMY 2002-30391 communique
Patent documentation 5: TOHKEMY 2009-280850 communique
Summary of the invention
Yet, in these patent documentations 2 ~ 5 in the disclosed technology, for the research of suitable composition range may not be abundant.Especially these almost do not consider manufacturing (manufacturability), the generation of the crackle in steel billet stage (slab stage) and to be referred to as the generation of surface imperfection (surface defect) of scab (scab) remarkable is difficult to avoid because of yield rate (yield ratio) cost that causes rise (cost rise) that descends.
The present invention In view of the foregoing finishes, its purpose be to provide a kind of can be at a low price and the structure stainless steel plate of excellent corrosion resistance that produce, weld part expeditiously.
People among the inventor is for solving found that chemical ingredients, particularly Mn that above-mentioned problem conducts in-depth research, the content of Ti and the balance of each composition (balance) are adjusted into proper range, then can suppress near the intergranular corrosion (intergranular corrosion) that causes because of the Cr disappearance the grain boundary, and welding heat affected zone (welded heataffected zone) can be formed the tissue take martensite (martensite) as main body, thereby the parameter shown in the patent documentation 5 (F value) has been proposed.And then, the inventor etc. are based on above opinion, particularly to found that on the basis of containing in right amount Al that manufacturing continues to study in great detail, V, Ca, O are reduced to below the specialized range, and will be set as suitable scope as the FFV value of the new argument that represents the manufacturing quality, scab (surface imperfection) that can significantly descend thus crackle of steel billet (slab crack) and cause because of inclusion, thus the present invention finished.
Namely, the invention provides a kind of structure stainless steel plate of corrosion resistance at welded part excellence, it is characterized in that, in quality %, contain: C:0.01 ~ 0.03%, N:0.01 ~ 0.03%, Si:0.10 ~ 0.40%, Mn:1.5 ~ 2.5%, below the P:0.04%, below the S:0.02%, Al:0.05 ~ 0.15%, Cr:10 ~ 13%, Ni:0.5 ~ 1.0%, Ti:4 * (C+N) ~ 0.3%(is wherein, C, N represents the content (quality %) of these elements), and, be defined as below the V:0.05%, below the Ca:0.0030%, below the O:0.0080%, and, the F value and the FFV value that represent with following formula satisfy F value≤11, FFV value≤9.0, remainder is made of Fe and the inevitable impurity of F.
F value=Cr+2 * Si+4 * Ti-2 * Ni-Mn-30 * (C+N)
FFV value=Cr+3 * Si+16 * Ti+Mo+2 * Al-2 * Mn-4 * (Ni+Cu)-40 * (C+N)+20 * V
Wherein, in these formulas, each symbol of element is the content (quality %) of these elements.
In addition, the invention provides a kind of structure stainless steel plate of corrosion resistance at welded part excellence, it is characterized in that, on the basis of mentioned component, in quality %, also contain below the Cu:1.0%.
In addition, the invention provides a kind of structure stainless steel plate of corrosion resistance at welded part excellence, it is characterized in that, on the basis of mentioned component, in quality %, also contain below the Mo:1.0%.
In addition, the invention provides a kind of structure manufacture method of stainless steel plate, it is characterized in that, after the temperature with heating steel billet to 1100 ~ 1300 ℃, carry out hot rolling in the temperature province greater than 1000 ℃, perhaps, after carrying out above-mentioned hot rolling, implement pickling after hot-rolled sheet not being annealed or under 600 ~ 1000 ℃ temperature, annealing, wherein, it is rolling hot roughing more than 30% that described hot rolling comprises the draft that carries out at least more than 1 time
This steel billet has following composition, namely, in quality %, contain: C:0.01 ~ 0.03%, N:0.01 ~ 0.03%, Si:0.10 ~ 0.40%, Mn:1.5 ~ 2.5%, below the P:0.04%, below the S:0.02%, Al:0.05 ~ 0.15%, Cr:10 ~ 13%, Ni:0.5 ~ 1.0%, Ti:4 * (C+N) ~ 0.3%(is wherein, C, N represents the content (quality %) of these elements), and be defined as below the V:0.05%, below the Ca:0.0030%, below the O:0.0080%, and, the F value and the FFV value that represent with following formula satisfy F value≤11, FFV value≤9.0, remainder is made of Fe and inevitable impurity.
F value=Cr+2 * Si+4 * Ti-2 * Ni-Mn-30 * (C+N)
FFV value=Cr+3 * Si+16 * Ti+Mo+2 * Al-2 * Mn-4 * (Ni+Cu)-40 * (C+N)+20 * V
Wherein, in these formulas, each symbol of element is the content (quality %) of these elements.
In addition, the invention provides a kind of structure of corrosion resistance at welded part excellence with the manufacture method of stainless steel plate, it is characterized in that, on the basis of mentioned component, in quality %, also contain below the Cu:1.0%.
In addition, the invention provides a kind of structure of corrosion resistance at welded part excellence with the manufacture method of stainless steel plate, it is characterized in that, on the basis of mentioned component, in quality %, also contain below the Mo:1.0%.
According to the present invention, can obtain can be at a low price and produce expeditiously, be suitable for as transporting for example structure stainless steel plate of vehicle body purposes excellent corrosion resistance material, weld part of the lorry of coal, iron ore (railway freight-car).
Description of drawings
Fig. 1 is the coordinate diagram of the relation of expression FFV value and surface imperfection incidence.
Fig. 2 is the optical microscope photograph of observation example of situation that can confirm the corrosion of dell shape in the test film cross section welding heat affected zone that is illustrated in after sulfuric acid-copper sulfate corrosion test.
Embodiment
Below, the present invention is described in detail.
At first, one-tenth of the present invention is grouped into describes.Below in the explanation, % represents quality %.
·C：0.01~0.03%
·N：0.01~0.03%
In order to obtain as structure with stainless steel plate needed intensity, C and N all need to contain more than 0.01%.On the other hand, if the content of C, N greater than 0.03%, then Cr carbide or Cr carboritride become and separate out easily, the erosion resistance of erosion resistance, particularly welding heat affected zone descends.In addition, welding heat affected zone solidifies, and toughness also descends.Therefore, make the content of C and N be 0.01 ~ 0.03% scope.More preferably C is that 0.015 ~ 0.025%, N is 0.012 ~ 0.02% scope.
·Si：0.10~0.40%
Si is the element that can be used as reductor, in order to obtain this effect, need to contain more than 0.10%.On the other hand, if its content greater than 0.40%, then makes the toughness of hot-rolled steel sheet descend.Therefore, making Si content is 0.10 ~ 0.40% scope.Preferably be limited to 0.20% down, on be limited to 0.30%.
·Mn：1.5~2.5%
Mn is as reductor, and is to guarantee that as being used for structure with the useful element of strengthening element of the needed intensity of stainless steel plate, also is the austenite stabilizer element under the high temperature.In addition, among the present invention, be that the microtexture with welding heat affected zone is controlled to be the important element in martensitic stucture aspect with desirable volume fraction.In order to bring into play such effect, its content is necessary for more than 1.5%.On the other hand, contain greater than 2.5%, then its effect not only can be saturated, and content becomes excessive and toughness is descended, and also makes the desquamation decline in the manufacturing process, and the effects on surface proterties is brought negative impact, and cost of alloy also increases.Therefore, making the content of Mn is 1.5 ~ 2.5% scope.1.8 ~ 2.5% scope more preferably.1.85 ~ 2.0% scope more preferably.
Below the P:0.04%
From the viewpoint of hot workability, preferred P is more few better, and the admissible higher limit of its content is made as 0.04%.More preferably below 0.035%.
Below the S:0.02%
From the viewpoint of hot workability and erosion resistance, preferred S is more few better, and the admissible higher limit of its content is made as 0.02%.Be preferably below 0.005%.
·Al：0.05~0.15%
Usually contain Al for deoxidation, but among the present invention, find that Al can be to manufacturing, the inhibition that particularly crackle in the steel billet stage is occured is worked effectively, contains in right amount in order to bring into play such function.In order to suppress the generation of crackle of steel billet, containing on the basis of Al, describedly as described later also need to reduce V, Ca, O, and need to make FFV value optimization.The mechanism that can improve crackle of steel billet by containing Al is still not clear, but infer to be that effect because of the rationalization of phase fraction and control inclusion morphology causes.In order to obtain such effect, need to contain the Al more than 0.05%.On the other hand, if its content greater than 0.15%, is the reason that inclusion becomes surface imperfection thereby then generate large-scale Al.Therefore, making the content of Al is 0.05 ~ 0.15% scope.0.080 ~ 0.150% scope more preferably.0.085 ~ 0.120% scope more preferably.
·Cr：10~13%
Cr forms the passivation tunicle, guarantees erosion resistance, particularly guarantees the necessary element in erosion resistance aspect of welding heat affected zone, in order to obtain this effect, need to contain more than 10%.On the other hand, if contain Cr greater than 13%, then not only cost rises, and also is difficult at high temperature guarantee enough austenite phases the martensitic stucture of the needed minute rate of welding heat affected zone after being difficult to obtain welding at weld part.Its result causes the decline of the intergranular corrosion resistance of welding heat affected zone.Therefore, making Cr content is 10 ~ 13% scope.Be preferably 10.5 ~ 12.5%.
·Ni：0.5~1.0%
For the purpose of guaranteeing intensity and toughness, contain the Ni more than 0.5%.On the other hand, Ni is the element of high price, from the viewpoint of economy, its upper limit is made as 1.0%.Should illustrate, Ni and Mn similarly are the austenite stabilizer element under the high temperature, be controlled in the microtexture with welding heat affected zone martensitic stucture with desirable volume fraction aspect be useful, but among the present invention, its effect can fully obtain by adding Mn, so the content of Ni is preferably 0.5 ~ 1.0% scope.0.60 ~ 1.0% scope more preferably.0.60 ~ 0.90% scope more preferably.
·Ti：4×（C＋N）~0.3%
Ti is used among the present invention obtaining the excellent important element of corrosion resistance at welded part, particularly for the necessary element of the intergranular corrosion resistance that improves welding heat affected zone.Ti with the C in the steel, N as carbide, nitride or the carboritride of Ti (after, these 3 kinds in carbide, nitride, carboritride is generally called, be designated as carboritride etc.) separate out fixingly, have the effect of the generation of the carboritride that suppresses Cr etc.Among the present invention, the welding heat affected zone of steel plate has the tissue that is made of ferrite and martensite, and from this angle of erosion resistance, follows in cooling on the ferritic phase of the separating out part of carboritride etc., and the lower general who has surrendered of erosion resistance becomes problem.In the steel plate of the present invention, solve the carboritride etc. of Cr on the welding heat affected zone in when welding by containing Ti and separate out, the Cr disappearance occurs near the grain boundary thus, particularly in the problem of ferritic phase part intergranular corrosion resistance decline.In order to bring into play such effect, the content of Ti need to be made as (wherein, C, N represent the content (quality %) of these elements) more than 4 * (C+N).On the other hand, surpass 0.3% and contain in a large number that then its effect is not only saturated, in steel, also separate out the carboritride of a large amount of Ti etc., cause the toughness variation.Therefore, the content of Ti is made as 4 * (C+N) ~ 0.3%.0.180 ~ 0.230% scope more preferably is effectively so that the mode that the content of Ti satisfies more than 4 * (C+N) simultaneously reduces C, N.
Among the present invention, for productivity (qualification rate), manufacturing, scab (surface imperfection) in order to suppress crackle that the steel billet stage produces and to produce because of inclusion especially is importantly by following V, Ca, the O of reducing.
Below the V:0.05%
V is contained as the impurity of Cr raw material etc. mostly, is that non-original meaning ground contains sometimes, but especially for the generation of the crackle that suppresses the steel billet stage, must strictly limit its content.From the above point of view, the content of V need to be made as below 0.05%.Preferred scope is below 0.03%, and further preferred scope is less than 0.03%.Be below 0.01% by making content, can access better crackle inhibition, but owing to need to carry out the screening of raw material, therefore unfavorable economically.
Below the Ca:0.0030%
Ca generates low-melting inclusion, particularly can become the reason of the surface imperfection that causes because of inclusion.Therefore, need strictly to limit its content among the present invention, its upper limit is made as 0.0030%.Ca content is more low more preferred, is preferably 0.0010%, more preferably below 0.0002%, but need to carry out raw material screening, and is therefore unfavorable economically.
Below the O:0.0080%
For inhibited oxidation system the nucleation and growth of inclusion, guarantee high productivity, need to reduce the content of O, its upper limit is made as 0.0080%.Be preferably below 0.0060%.
And, among the present invention, be made as suitable scope by making F value shown below, FFV value, significantly improve erosion resistance, productivity.
F value≤11
The F value with the expression of Cr+2 * Si+4 * Ti-2 * Ni-Mn-30 * (C+N) (wherein, each symbol of element is the content (quality %) of these elements), being the parameter of the microtexture (microstructure) of the welding heat affected zone when judging welding, more specifically is the parameter of judging the volume fraction (the remaining rate of ferritic structure) of martensitic stucture.Being exposed in the position under the high temperature as welding heat affected zone, its part metamorphosis be austenite (austenite) (or a part further metamorphosis be delta ferrite (delta ferrite)), and this metamorphosis in process of cooling is martensite.Its ratio is subjected to the impact of balance of the amount of ferrite stabilizer (ferrite generting element (ferrite formationelements)) and austenite stabilizer element (austenite generting element (austenite formationelements)).Represent that the coefficient in the formula of above-mentioned F value is that positive element (Cr, Si, Ti) is ferrite stabilizer, coefficient is austenite stabilizer element for negative element (Ni, Mn, C, N).That is, the larger ferritic structure of F value easier residual (volume fraction of ferritic structure is large, and namely the volume fraction of martensitic stucture is little), less ferritic structure more is difficult to residual (volume fraction of ferritic structure is little, that is, the volume fraction of martensitic stucture is large).
In the patent documentation 5, the relation of the volume fraction of the martensitic stucture of investigation F value and welding heat affected zone, further estimate near the erosion resistance the welding heat affected zone by sulfuric acid-copper sulfate corrosion test, thereby realize the optimization of composition, and among the present invention also with above-mentioned patent documentation 5 similarly, raising for the erosion resistance that realizes welding heat affected zone is made as (martensite volume fraction: more than 40%) below 11 with above-mentioned F value.Preferred F value: (the martensite volume fraction is more than 60%) below 10.5, more preferably below 10.Should illustrate that from the viewpoint of the erosion resistance of weld part, preferably the lower limit with the F value is made as more than 5.0.Further preferred scope is more than 6.0.
FFV value≤9.0
The FFV value represents (wherein with Cr+3 * Si+16 * Ti+Mo+2 * Al-2 * Mn-4 * (Ni+Cu)-40 * (C+N)+20 * V, each symbol of element is the content (quality %) of these elements), be as the new value that derives of the index that represents manufacturing among the present invention.This FFV value is to have considered the value that balances each other in the hot rolling, therefore carry out above-mentioned composition adjustment, particularly carry out reducing this value on the basis of restriction of the upper limit of the containing of Al, V, Ca, O, thereby can significantly reduce the crackle in invar base stage and inclusion and the generation of the surface imperfection that causes.Notable feature of the present invention is by realizing that the Al that does not consider when F value designed measures the optimization of the new argument of considering, thereby has successfully significantly suppressed the decline of the yield rate that the generation because of surface imperfection causes.Although the mechanism that the manufacturing that the optimization of FFV value causes is improved is not yet fully clear and definite, by FFV value is made as below 9.0, thereby can significantly improves manufacturing, so the FFV value is made as below 9.0.Be preferably below 8.5.Should illustrate, in order to reduce the FFV value, effectively reduce the Cr amount, increase C, N amount, erosion resistance is descended.Therefore, preferably the lower limit of FFV value is made as more than 5.0.Further preferred scope is more than 6.0.
In the steel plate of the present invention that is used with the state of hot-rolled sheet or hot-roll annealing plate, in order to reduce surface imperfection, importantly control crackle and the inclusion in steel billet stage.The generation of surface imperfection not only makes yield rate decline to a great extent, and crackle, this part the apparent variation of scabbing also can become the starting point that rust produces, and must excise object part during therefore as product export.Should illustrate, contain Mo, V, Cu in the formula of above-mentioned FFV value, but the situation that does not contain these in the steel is also arranged, when not containing these, wherein the one-tenth that does not contain is divided into 0% calculate the FFV value.
Fig. 1 represents the relation of FFV value and surface imperfection incidence.For the incidence of defective, the FFV value that obtains of the length computation by the part that will be occured by defective with respect to the coil of strip total length is made as the suitable scope below 9.0 as can be known, thereby can significantly suppress the generation of surface imperfection.
Among the present invention, except mentioned component, can as required, contain Cu in following scope.
Below the Cu:1.0%
Cu is the element that improves erosion resistance, the element that crevice corrosion (crevice corrosion) is reduced.Therefore, can add in the situation of high corrosion resistance requiring.But if contain greater than 1.0%, then hot workability (hot workability) descends, and balancing each other under the high temperature be broken, and is difficult to obtain desirable tissue at welding heat affected zone.Therefore, contain in the situation of Cu, its upper limit is made as 1.0%.To improve the erosion resistance effect in order giving full play to, effectively to contain more than 0.3%.Preferred scope is 0.3 ~ 0.5%.
Below the Mo:1.0%
Mo is the element that improves erosion resistance, particularly can add in the situation of high corrosion resistance requiring.But if contain greater than 1.0%, then cold-workability descends, and causes the surface roughening under the hot rolling, and surface quality extremely descends.Therefore, contain in the situation of Mo, its upper limit is made as 1.0%.In order to give full play to erosion resistance, effectively contain more than 0.03%.More preferably scope is 0.1 ~ 1.0%.
Among the present invention, except improving erosion resistance by Cu, the Mo that contains below 1.0% as described above, can also contain other elements according in the past knowledge, such as improving ductility etc. by the B that contains below 0.005%, and consider in this case the no less important that balances each other under the high temperature.Should illustrate that Nb is the strong stability element, be combined with C, N and significantly destroy and balance each other, so not add among the present invention.Should illustrate that more than the remainder beyond the element of regulation is Fe and inevitable impurity.
For steel plate of the present invention, in order to realize improving the erosion resistance of welding heat affected zone, by above-mentioned F value is made as below 11, be more than 40% thereby make the martensite volume fraction of welding heat affected zone.Further preferably the F value is made as below 10.5, the martensite volume fraction of welding heat affected zone is become more than 60%.More preferably below 10, the martensite volume fraction of this moment is more than 80%.In addition, in the steel plate of the present invention, mother metal section take volume fraction more than 50% as ferritic structure.The tissue of remainder particularly under the state of the former state of hot rolling, exists martensitic phase and remaining γ mutually, and a part contains the tissue of carboritride etc.Particularly almost 100% have the ferritic phase tissue in volume fraction during the organizing of the hot-roll annealing plate after being made as suitable compositing range and implementing hot-rolled sheet annealing under suitable annealing conditions as hereinafter described, processibility is very excellent.
Next, the manufacture method of stainless steel plate of the present invention described.
The manufacture method of stainless steel plate of the present invention gets final product according to conventional methods, be not particularly limited, but but as the method for high efficient production, recommend following methods: will be smelted into steel that mentioned component forms by continuous casting wait make steel billet after, make coils of hot-rolled steel, after as required it being annealed, carry out de-scaling (descaling) (shot-peening (shot blasting), pickling (pickling) etc.), make stainless steel plate of the present invention.
Below, be elaborated.
At first, utilize the normally used known smelting furnaces such as converter (steel converter) or electric furnace (electric furnace) that the molten steel that is adjusted into one-tenth of the present invention and is grouped into is carried out melting, then, utilize vacuum outgas (RH method), VOD(Vacuum Oxygen Decarburization) method, AOD(Argon Oxygen Decarburization) the known method of refining such as method carries out refining, then, utilize Continuous casting process (continuous casting) or ingot casting-cogging method to make steel billet (steel material).From the viewpoint of productivity and quality, casting preferably casts continuously.In addition, in order to ensure the draft that utilizes hot roughing described later, preferably be made as more than the 100mm steel billet is thick.Preferred scope is more than the 200mm.
Then, after the temperature with heating steel billet to 1100 ~ 1300 ℃, carry out hot rolling and make hot-rolled steel sheet.For the surface roughening (surface roughness resistance) that prevents hot-rolled sheet with improve wrinkle properties (anti-ridging property or ridging property) after cold rolled annealed, billet heating temperature is more high more preferred, but greater than 1300 ℃, then steel billet sagging (slab sag) is remarkable, thereby and coarse grains the toughness of hot-rolled sheet is descended.On the other hand, if be Heating temperature less than 1100 ℃, then the load in the hot rolling is increased, and the surface roughening in the hot rolling becomes significantly, and the recrystallize in the hot rolling (recrystallization) becomes insufficient, and the toughness of hot-rolled sheet still can descend.
The operation of preferred hot roughing is greater than 1000 ℃ temperature province, is that rolling more than 30% carries out more than 1 time at least with draft.By under this is suppressed, being rolled, thereby make the crystal structure granular of steel plate, improve toughness.After the hot roughing, according to well-established law (condition of common hot finishing), carry out hot finishing.
Can directly be used as structured material by the hot-rolled sheet about the thickness of slab 2.0 ~ 8.0mm of hot rolling manufacturing, perhaps, carry out without annealing being used as structured material after the pickling.For hot-rolled sheet, implement pickling after can be under 600 ~ 1000 ℃ temperature hot-rolled sheet being annealed.If the annealing temperature of hot-rolled sheet is less than 600 ℃, martensitic phase, the remaining γ phase that may exist under then sometimes still can the former state state of residual hot rolling, ferritic structure will become less than 50% in volume fraction, can't obtain sufficient processibility.On the other hand, if greater than 1000 ℃, then thickization of crystal grain is remarkable, and toughness descends.The annealing of hot-rolled sheet preferably keeps more than 1 hour by so-called pot annealing (box annealing) under 600 ~ 1000 ℃ temperature of regulation.In addition, if annealing temperature is too high, then sometimes arrive the temperature that produces γ metamorphosis, thus not preferred.Therefore, composition need to be adjusted into suitable scope and the suitable temperature range of selection to forming.In the compositing range of steel of the present invention, roughly be made as in 600 ~ 900 ℃ the situation of annealing temperature, in volume fraction, almost 100% becomes ferritic phase, thereby preferred this temperature range.
In the welding of stainless steel plate of the present invention, electric-arc welding (arc welding), seam that TIG welding, MIG are welded as representative weld the common welding processs such as (seam welding), the welding of spot welding (spot welding) constant resistance, laser welding (laser welding) and all can use.
Embodiment
Utilize converter-VOD-Continuous casting process will have the stainless steel that the one-tenth shown in the table 1 is grouped into and make the thick steel billet of 200mm.After the temperature with these heating steel billets to 1180 ℃, make the hot-rolled sheet of the coiled material shape of thickness of slab 5.0mm by hot rolling.The hot rolling end temp is 900 ℃, and the coiling temperature after the hot rolling is 700 ℃.To the hot-rolled steel sheet that obtains 690 ℃ carry out 10 hours annealing after, carry out shot-peening and pickling, except scaling (oxide film).
Removed from these and to have cut out plane plate specimen (flat plate sample) steel plate behind the squama; the T-shaped test body that assembling is made of lower plate and vertical panel; carry out welded corner joint (both sideone pass fillet welding) (gas metal arc welding (gas metal arc welding), the shielding gas (shielding gas): 98 capacity %Ar-2 capacity %O of both sides one deck
2, flow: 20 liter/mins of clocks), make three welded corner joint test films.Solder bar is used the MGS-309LS processed of company of Kobe Steel Ltd, and heat input is the scope of 0.4 ~ 0.8kJ/mm.
Take the corrosion test sheet from the welded corner joint section of these welded corner joint test films, (Modified Strauss test, testing liquid based on ASTM A262practice E and ASTM A763practice Z are Cu/6%CuSO to carry out sulfuric acid-copper sulfate corrosion test
4/ 0.5%H
2SO
4, with end surface grinding test film dipping 20 hours in this boiling liquid), observe near the corrosion condition the welding heat affected zone.
Fig. 2 is the optical microscope photograph of the observation example in the test film cross section after expression sulfuric acid-copper sulfate corrosion test.Shown in this photo, evaluation to welding heat affected zone is as follows, namely, can confirm intergranular corrosion, and then the average evaluation that can see the corrosion of very dark hole shape is C, the average evaluation that can confirm a little corrosion is B, and the average evaluation that does not confirm corrosion in the observation of opticmicroscope is A.In addition, the condition of surface after the pickling of hot-roll annealing plate is observed in whole total length.To be to be evaluated as a below 3% with the ratio that defective occurs with respect to the ratio of length total length, that can observe the surface imperfection that causes because of crackle of steel billet or inclusion as index, greater than 3% and be evaluated as b less than or equal to 30%, be evaluated as c greater than 30%.These be the results are shown in table 2.
Its result, in the No.1 as the inventive example within the scope of the invention ~ 5,10 ~ 13,15, the erosion resistance of weld part is good, and condition of surface is also very good.Relative therewith, break away among the No.9 as a comparative example and 14 of the scope of the invention in the F value, few at the martensite growing amount of welding heat affected zone, so intergranular corrosion resistance is obviously poor.In addition, being higher than scope of the present invention and Al at Si is lower than among the No.6 as a comparative example of scope of the present invention and the No.7 as a comparative example, 8,9 and 14 that the FFV value departs from the scope of the present invention, in the surface observation after hot-roll annealing, can observe in a large number steel billet cause crackle, the inclusion cause scabs.
Steel of the present invention can use with the state of hot-rolled sheet or hot-roll annealing plate, and therefore, the generation that scabs can make yield rate decline to a great extent.This is because the section of scabbing not only makes apparent variation, also can become the starting point that rust occurs, and must excise object part during therefore as product export.
Claims (6)
1. structure stainless steel plate, it is characterized in that, in quality %, containing: C:0.01 ~ 0.03%, N:0.01 ~ 0.03%, Si:0.10 ~ 0.40%, Mn:1.5 ~ 2.5%, P:0.04% are following, S:0.02% is following, Al:0.05 ~ 0.15%, Cr:10 ~ 13%, Ni:0.5 ~ 1.0%, Ti:4 * (C+N) ~ 0.3%, wherein, C, N represent the content in quality % of these elements
And, be defined as that V:0.05% is following, Ca:0.0030% following, below the O:0.0080%,
And the F value and the FFV value that represent with following formula satisfy F value≤11, FFV value≤9.0, and remainder is made of Fe and inevitable impurity;
F value=Cr+2 * Si+4 * Ti-2 * Ni-Mn-30 * (C+N)
FFV value=Cr+3 * Si+16 * Ti+Mo+2 * Al-2 * Mn-4 * (Ni+Cu)-40 * (C+N)+20 * V
Wherein, in these formulas, each symbol of element is the content in quality % of these elements.
2. structure stainless steel plate wherein, on the basis of the composition of claim 1, in quality %, also contains below the Cu:1.0%.
3. structure stainless steel plate wherein, on the basis of the composition of claim 1 or 2, in quality %, also contains below the Mo:1.0%.
4. a structure is with the manufacture method of stainless steel plate, it is characterized in that, after the temperature with heating steel billet to 1100 ~ 1300 ℃, carry out hot rolling in the temperature province that surpasses 1000 ℃, perhaps, after carrying out described hot rolling, implement pickling after hot-rolled sheet not being annealed or under 600 ~ 1000 ℃ temperature, annealing, wherein, to comprise the draft that carries out at least more than 1 time be rolling hot roughing more than 30% in described hot rolling
Described steel billet has following composition, namely, in quality %, containing: C:0.01 ~ 0.03%, N:0.01 ~ 0.03%, Si:0.10 ~ 0.40%, Mn:1.5 ~ 2.5%, P:0.04% are following, S:0.02% is following, Al:0.05 ~ 0.15%, Cr:10 ~ 13%, Ni:0.5 ~ 1.0%, Ti:4 * (C+N) ~ 0.3%, wherein, C, N represent the content in quality % of these elements
And, be defined as that V:0.05% is following, Ca:0.0030% following, below the O:0.0080%,
And the F value and the FFV value that represent with following formula satisfy F value≤11, FFV value≤9.0, and remainder is made of Fe and inevitable impurity;
F value=Cr+2 * Si+4 * Ti-2 * Ni-Mn-30 * (C+N)
FFV value=Cr+3 * Si+16 * Ti+Mo+2 * Al-2 * Mn-4 * (Ni+Cu)-40 * (C+N)+20 * V
Wherein, in these formulas, each symbol of element is the content in quality % of these elements.
5. a structure is with the manufacture method of stainless steel plate, wherein, on the basis of the composition of the steel billet of claim 4, in quality %, also contains below the Cu:1.0%.
6. a structure is with the manufacture method of stainless steel plate, wherein, on the basis of the composition of the steel billet of claim 4 or 5, in quality %, also contains below the Mo:1.0%.
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| JP2010-124059 | 2010-05-31 | ||
| JP2010124059 | 2010-05-31 | ||
| PCT/JP2011/062640 WO2011152475A1 (en) | 2010-05-31 | 2011-05-26 | Structural stainless steel sheet having excellent corrosion resistance in welded part, and method for producing same |
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| CN102933732A true CN102933732A (en) | 2013-02-13 |
| CN102933732B CN102933732B (en) | 2016-06-29 |
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| EP (1) | EP2578715B1 (en) |
| JP (1) | JP4893866B2 (en) |
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| TW201418549A (en) * | 2012-11-12 | 2014-05-16 | Shehkai Prec Co Ltd | Composite concrete screw anchor |
| WO2015064077A1 (en) | 2013-10-31 | 2015-05-07 | Ｊｆｅスチール株式会社 | Ferrite-martensite two-phase stainless steel, and method for producing same |
| WO2015064128A1 (en) * | 2013-10-31 | 2015-05-07 | Ｊｆｅスチール株式会社 | Ferrite-martensite two-phase stainless steel exhibiting low-temperature toughness, and method for producing same |
| CN108690936B (en) * | 2018-06-13 | 2020-12-01 | 燕山大学 | Stainless steel rail material for welding high manganese steel frog and rail and preparation method thereof |
| KR102173277B1 (en) * | 2018-11-06 | 2020-11-03 | 주식회사 포스코 | Hot-rolled steel sheet with excellent low temperature impact toughness and manufacturing method thereof |
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| JPS6199628A (en) * | 1984-10-19 | 1986-05-17 | Kawasaki Steel Corp | Manufacture of austenitic stainless steel sheet or strip |
| CN1826202A (en) * | 2003-09-05 | 2006-08-30 | 住友金属工业株式会社 | Welded structure excellent in resistance to stress corrosion cracking |
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| JPH03249150A (en) * | 1990-02-27 | 1991-11-07 | Nippon Steel Corp | Ferritic stainless steel having excellent toughness in weld zone |
| SU1723191A1 (en) * | 1990-06-25 | 1992-03-30 | Волгоградский Политехнический Институт | Stainless steel |
| JP2000080416A (en) * | 1998-08-31 | 2000-03-21 | Kawasaki Steel Corp | MANUFACTURE OF HIGH Cr MARTENSITIC WELDED STEEL PIPE FOR LINE PIPE EXCELLENT IN WELDABILITY AND CORROSION RESISTANCE |
| JP3508698B2 (en) * | 2000-06-06 | 2004-03-22 | Ｊｆｅスチール株式会社 | Stainless steel hot rolled steel strip for civil and building structures with excellent initial rust resistance |
| CN1697889B (en) * | 2000-08-31 | 2011-01-12 | 杰富意钢铁株式会社 | Low carbon martensitic stainless steel and its manufacture method |
| JP2002121652A (en) * | 2000-10-12 | 2002-04-26 | Kawasaki Steel Corp | Cr-CONTAINING STEEL FOR AUTOMOBILE SUSPENSION |
| JP4457492B2 (en) | 2000-11-29 | 2010-04-28 | Ｊｆｅスチール株式会社 | Stainless steel with excellent workability and weldability |
| BRPI0412746B1 (en) * | 2003-07-22 | 2016-12-06 | Nippon Steel & Sumitomo Metal Corp | martensitic stainless steel |
| JP2006219717A (en) * | 2005-02-09 | 2006-08-24 | Nippon Steel Corp | Steel sheet for vessel having superior deformation resistance, surface characteristic and weldability, and manufacturing method therefor |
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| JP5225620B2 (en) * | 2006-07-04 | 2013-07-03 | 新日鐵住金ステンレス株式会社 | Low chromium-containing stainless steel excellent in corrosion resistance of heat-affected zone multiple times and its manufacturing method |
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| JPS6199628A (en) * | 1984-10-19 | 1986-05-17 | Kawasaki Steel Corp | Manufacture of austenitic stainless steel sheet or strip |
| CN1826202A (en) * | 2003-09-05 | 2006-08-30 | 住友金属工业株式会社 | Welded structure excellent in resistance to stress corrosion cracking |
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| Publication number | Publication date |
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| ES2643150T3 (en) | 2017-11-21 |
| JP4893866B2 (en) | 2012-03-07 |
| KR101409291B1 (en) | 2014-06-18 |
| JP2012012702A (en) | 2012-01-19 |
| CN102933732B (en) | 2016-06-29 |
| AU2011259992A1 (en) | 2012-12-20 |
| TWI439555B (en) | 2014-06-01 |
| RU2522065C1 (en) | 2014-07-10 |
| KR20130034025A (en) | 2013-04-04 |
| EP2578715A1 (en) | 2013-04-10 |
| US20130126052A1 (en) | 2013-05-23 |
| WO2011152475A1 (en) | 2011-12-08 |
| EP2578715B1 (en) | 2017-07-12 |
| CA2799696A1 (en) | 2011-12-08 |
| AU2011259992B2 (en) | 2013-12-19 |
| CA2799696C (en) | 2015-11-17 |
| BR112012030684B1 (en) | 2018-08-14 |
| TW201207128A (en) | 2012-02-16 |
| EP2578715A4 (en) | 2015-08-19 |
| BR112012030684A2 (en) | 2017-12-05 |
| RU2012157554A (en) | 2014-07-20 |
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