CN109563589A - Austenite stainless steel - Google Patents

Austenite stainless steel Download PDF

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Publication number
CN109563589A
CN109563589A CN201780048557.4A CN201780048557A CN109563589A CN 109563589 A CN109563589 A CN 109563589A CN 201780048557 A CN201780048557 A CN 201780048557A CN 109563589 A CN109563589 A CN 109563589A
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stainless steel
overlay film
base material
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CN109563589B (en
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栗原伸之佑
相良雅之
小薄孝裕
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Nippon Steel Corp
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Abstract

A kind of austenite stainless steel, it has: base material, with at least part of overlay film for being formed in surface possessed by base material, the chemical composition of base material is calculated as C:0.05% or less with quality %, Si:1.0% or less, Mn:2.0% or less, P:0.040% or less, S:0.010% or less, O:0.020% or less, N: less than 0.050%, Ni:12.0~27.0%, Cr:15.0% is more than and less than 20.0%, Cu: greater than 3.5% and be 8.0% or less, Mo: greater than 2.0% and be 5.0% or less, Co:0.05% or less, Sn:0.05% or less, V:0~0.5%, Nb:0~1.0%, Ti:0~0.5%, W:0~5.0%, Z R:0~1.0%, Al:0~0.5%, Ca:0~0.01%, B:0~0.01%, REM:0~0.01%, surplus: the chemical composition of Fe and impurity, the maximum Cr depth of overlay film meets [(Cr+Ni+Cu+Mo)/Fe >=1.0] in terms of at%.

Description

Austenite stainless steel
Technical field
The present invention relates to austenite stainless steels, more particularly to the austenite stainless steel that acid resistance is excellent.
As thermal power generation with or industry boiler oil and oil and coal for using etc so-called " fossil fires Include in material " sulphur (S).Therefore, if fossil fuel burns, oxysulfide (SO can be generated in the offgasx).The temperature of exhaust gas If reduced, SOxWith the reaction of moisture in gas as sulfuric acid, in the component surface for being in dew-point temperature low temperature below Moisture condensation, generates corrosion of sulfuric acid at dew point as a result,.
It similarly, include SO in circulation even if in the flue gas desulfurization equipment used in various industriesxGas the case where Under, if temperature reduces, it can also generate corrosion of sulfuric acid at dew point.It will include SO for the sake of easy in following this specificationxGas Body is denoted as exhaust gas to be illustrated.
Since above-mentioned phenomenon can be generated, in heat exchanger used in waste gas system etc., in component surface sulfuric acid Exhaust gas temperature is remained 150 DEG C or more of high temperature by the mode not condensed.
However, from the viewpoint of energy needs increase and energy effective use in recent years, in order to return as effectively as possible Heat energy is received, for example, in the presence of the dew point trend below that the exhaust gas temperature from heat exchanger is reduced to sulfuric acid, gradually requirement pair Sulfuric acid has indefatigable material.
In the case where exhaust gas temperature is not remained 150 DEG C or more, in 140 DEG C or so of temperature of the exhaust gas of general composition It spends under domain, 80% or so high-concentration sulfuric acid can condense in component surface.Under such environment, so-called " low-alloy steel " gradually It is used initially as various components with steel.This is because, for the sulfuric acid of foregoing high-temperature high concentration, low-alloy steel it is resistance to Corrosivity is higher than general stainless steel.
On the other hand, as recorded in non-patent literature 1, in the area of low 20~60 DEG C of the temperature of dew point than sulfuric acid In domain, the amount of the sulfuric acid of moisture condensation becomes at most, and therefore, corrosion caused by sulfuric acid becomes larger.Therefore, exhaust gas temperature is not remained In the case where 150 DEG C or more, it is however generally that, become the region for most requiring corrosion resistance, herein, sulphur at the temperature near 100 DEG C The concentration of acid becomes about 70%.However, in this region, not only general stainless steel, even the etching extent of low-alloy steel is also big, It is not available.
So far, for the component in sulphuric acid environment, the side that specific resistant material can be used is proposed A kind of resistant to sulfuric acid dew point corrosion stainless steel having superior hot workability is disclosed in case, such as patent document 1
In addition, disclosing a kind of austenite stainless steel in patent document 2, there is excellent patience for sulfuric acid corrosion And processability is also excellent.
Existing technical literature
Patent document
Patent document 1: Japanese Unexamined Patent Publication 4-346638 bulletin
Patent document 2: Japanese Patent No. 3294282
Non-patent literature
Non-patent literature 1: Nagano win husband, " corrosion of sulfuric acid at dew point ", anticorrosion technique, 1977, volume 26, No. 12, p.731-740
Summary of the invention
Problems to be solved by the invention
N (nitrogen) that the stainless steel recorded in patent document 1 contains 0.05 weight % or more attempts to ensure that austenite structure Stabilisation and corrosion resistance.However, in the case where the N containing 0.05 weight % or more, compound Austria added with Cu, Cr and Mo The corrosion resistance against sulfuric acid of family name's system stainless steel can reduce instead.In turn, in the case where N content is 0.05 weight % or more, such as Fruit increases Cu content in order to improve corrosion resistance against sulfuric acid, then there is the reduction of the hot-workability in the temperature field less than 1000 DEG C The problem of becoming apparent.
In addition, the austenite stainless steel recorded in patent document 2 has excellent corrosion resistance against sulfuric acid and processability.So And about corrosion resistance against sulfuric acid, still there are further rooms for improvement.
The present invention solves the above problem, it is intended that providing in the environment of the condensation of the sulfuric acid of high concentration with excellent Different acid proof austenite stainless steel.
It should be noted that " environment of the sulfuric acid condensation of high concentration " refers to the temperature at 50~100 DEG C in record below Spend the environment that the sulfuric acid of lower concentration 40~70% can condense.
The solution to the problem
The present invention makes in order to solve the above problems, using following austenite stainless steels as purport.
(1) a kind of austenite stainless steel, has: base material and being formed in surface possessed by aforementioned base material at least The overlay film of a part,
The chemical composition of aforementioned base material is calculated as with quality %
C:0.05% or less,
Si:1.0% or less,
Mn:2.0% or less,
P:0.040% or less,
S:0.010% or less,
O:0.020% or less,
N: less than 0.050%,
Ni:12.0~27.0%,
Cr:15.0% more than and less than 20.0%,
Cu: greater than 3.5% and for 8.0% or less,
Mo: greater than 2.0% and for 5.0% or less,
Co:0.05% or less,
Sn:0.05% or less,
V:0~0.5%,
Nb:0~1.0%,
Ti:0~0.5%,
W:0~5.0%,
Zr:0~1.0%,
Al:0~0.5%,
Ca:0~0.01%,
B:0~0.01%,
REM:0~0.01%,
Surplus: Fe and impurity,
The chemical composition that the Cr concentration of aforementioned overlay film becomes maximum maximum Cr depth meets following formula (i).
(Cr+Ni+Cu+Mo)/Fe≥1.0···(i)
Wherein, each element symbol in above-mentioned formula indicates the content (at%) of each element.
(2) austenite stainless steel according to above-mentioned (1), wherein the chemical composition of aforementioned base material is in terms of quality % Containing being selected from
V:0.01~0.5%,
Nb:0.02~1.0%,
Ti:0.01~0.5%,
W:0.1~5.0%,
Zr:0.02~1.0%,
Al:0.01~0.5%,
Ca:0.0005~0.01%,
The and of B:0.0005~0.01%
REM:0.0005~0.01%
One or more of.
(3) austenite stainless steel according to above-mentioned (1) or (2), wherein the Cr concentration of aforementioned overlay film becomes minimum Minimum Cr depth be present in than aforementioned maximum Cr depth closer to aforementioned base material side,
The chemical composition of aforementioned maximum Cr depth meets following formula (ii), and the chemical composition of aforementioned minimum Cr depth Meet following formula (iii).
Cr/(Ni+Cu+Mo)≥1.0···(ii)
Cr/(Ni+Cu+Mo)<1.0···(iii)
Wherein, each element symbol in above-mentioned formula indicates the content (at%) of each element.
The effect of invention
According to the present invention it is possible to obtain that there is excellent acid proof austenite in the environment of the condensation of the sulfuric acid of high concentration It is stainless steel.
Specific embodiment
Based on the inventors of the present invention's austenite stainless steel documented by the patent document 2, to further increasing resistance to sulfuric acid Corrosive method has carried out in-depth study repeatedly, as a result obtains following opinion.
In terms of improve corrosion resistance against sulfuric acid, with the sulfuric acid contact of high concentration, be formed in the overlay film on base material surface Composition becomes important.In overlay film, the total content of Cr, Ni, Cu and Mo relative to Fe by relativity are improved, can substantially be mentioned Highly-acidproof.
In addition, it is found that implementing to be heat-treated under the defined conditions to steel, to form the oxidation based on Fe on surface After overlay film, implements acid processing, melt Fe ingredient preferentially, it is possible thereby to be enriched with Cr, Ni, Cu and Mo in overlay film.
The present invention is made based on above-mentioned opinion.Hereinafter, each feature of the invention is described in detail.
1. constituting
Austenite stainless steel of the invention has: base material and being formed at least one of surface possessed by the base material The overlay film divided.For base material and overlay film, it is described in detail individually below.
2. about base material
The chemical composition of base material is described in detail.The restriction reason of each element is as described below.It should be noted that with Under explanation in about " % " of content refer to " quality % ".
C:0.05% or less
C is the element improve with intensity.But Cr carbide can be formed in conjunction with Cr and in crystal boundary, make Resistance to grain boundary corrosion reduces.Therefore, C content is set as 0.05% or less.It should be noted that needing the case where improving intensity Under, preferably contain more than 0.03%.On the other hand, in the case where preferentially ensuring corrosion resistance, C content is low to be advisable, and preferably sets It is 0.03% or less.Lower limit is without especially setting, but said effect in order to obtain, C content are preferably set to 0.01% or more.
Si:1.0% or less
Si is the element with deoxidation.But content can then encourage the drop of hot-workability if it exceeds 1.0% Low, the increase with Cu content interacts, so that being processed into product on an industrial scale becomes extremely difficult.Therefore, Si content is set It is 1.0% or less.Si content preferably 0.6% or less.Si is without centainly containing, and therefore, lower limit is not arranged especially, but in order to obtain Said effect, Si content are preferably set to 0.05% or more.In addition, extremely reducing Al for the purpose for improving hot-workability and containing In the case where amount, it is preferred that containing 0.1% or more Si, carry out deoxidation sufficiently.
Mn:2.0% or less
Mn, which has, to be fixed S and improves hot-workability and make the stabilized effect of austenite phase.But even if containing super The Mn of 2.0% amount is crossed, effect is also saturated, and only increases cost.Therefore, Mn content is set as 2.0% or less.Mn content is preferred 1.5% or less.Mn is without centainly containing, and therefore, lower limit is not arranged especially, but said effect in order to obtain, and Mn content is preferably set It is 0.1% or more.
P:0.040% or less
P is contained in steel in the form of impurity, hot-workability and corrosion resistance can be made to deteriorate, therefore, content is preferably most It measures low.Especially P content is if it exceeds 0.040%, then the deterioration of the corrosion resistance in the environment of the sulfuric acid condensation of high concentration is bright It is aobvious.Therefore, P content is set as 0.040% or less.
S:0.010% or less
S is contained in steel in the form of impurity, deteriorates hot-workability, and therefore, content is preferably low as far as possible.Especially S Content then will lead to the obvious deterioration of hot-workability if it exceeds 0.010%.Therefore, S content is set as 0.010% or less.
O:0.020% or less
O is contained in steel in the form of impurity, reduces hot-workability and ductility, content is preferably low as far as possible.Especially O Content is if it exceeds 0.020%, then the reduction of hot-workability and ductility is obvious, and therefore, O content is set as 0.020% or less.
N: less than 0.050%
For N, previous N is for the stabilized purpose of austenite structure or raising to the part such as spot corrosion or crevice corrosion The purpose of the patience of corrosion and energetically add.But in the environment of the condensation of the sulfuric acid of high concentration, the content of N becomes When 0.050% or more, Austria containing the Cr of Cu, the Mo more than 2.0% and 15.0% more than and less than 20.0% for having more than 3.5% The corrosion resistance of family name's system stainless steel can reduce instead.In turn, even if making the upper limit of the content of Cu and Mo be respectively 8.0% He In the case where 5.0%, if the content of N becomes 0.050% or more, hot-workability can also be reduced.In order to austenite not The steel that becomes rusty assigns the corrosion resistance and hot-workability in the environment of the sulfuric acid condensation of high concentration, and N content is set as less than 0.050%.It needs It is noted that the lower N content the better, preferably 0.045% or less.
Ni:12.0~27.0%
Ni has the stabilized effect of austenite phase that makes, and also has resistance in the environment for the sulfuric acid condensation for improving high concentration Corrosive effect.In order to substantially ensure such effect, the Ni of the amount containing 12.0% or more is needed.But even if contain More than 27.0%, effect is also saturated.In turn, Ni is expensive element, and therefore, cost can become high, lacks economy.Cause This, Ni content is set as 12.0~27.0%.It should be noted that in order to ensure in the environment that the sulfuric acid of high concentration condenses sufficiently Corrosion resistance, preferably contain more than the Ni of 15.0% amount, be further preferably more than the Ni of 20.0% amount.
Cr:15.0% is more than and less than 20.0%
Cr is to the effective element of corrosion resistance for ensuring austenite stainless steel.N is especially limited to above-mentioned content Austenite stainless steel in, if making the Cu and Mo of 15.0% or more Cr, preferably 16.0% or more Cr Yu aftermentioned amount Contain together, then may insure good corrosion resistance in the environment of the condensation of the sulfuric acid of high concentration.But if excessively contain There is Cr, even if then in the case where reducing N content and the compound austenite stainless steel added with Cu and Mo, in aforesaid environmental Corrosion resistance can also deteriorate instead, and then can also generate the reduction of processability.If especially Cr content become 20.0% with On, then the corrosion resistance deterioration of the austenite stainless steel in aforesaid environmental becomes apparent.In addition, by being less than Cr content 20.0%, so as to improve the hot-workability of the compound austenite stainless steel added with Cu and Mo, it is easy on an industrial scale Fabricated product.Therefore, Cr content is set as 15.0% more than and less than 20.0%.
Cu: greater than 3.5% and be 8.0% or less
Cu is the necessary element for ensuring the corrosion resistance in sulphuric acid environment.By make be more than 3.5% Cu with before The Cr for the amount stated and the Mo of aftermentioned amount contain together, thus in the environment of the condensation of the sulfuric acid of high concentration, it can be to making on N The austenite stainless steel for stating content assigns good corrosion resistance.It is compound be added with Cu and Mo when Cu content it is more, then Corrosion resistance improvement effect is bigger, therefore, Cu content be preferably set to be more than 4.0% amount.It should be noted that by increasing Cu Content, although the corrosion resistance in aforesaid environmental improves, hot-workability can be reduced, especially Cu content if it exceeds 8.0%, Even if then making the above-mentioned content of N, the obvious deterioration of hot-workability can be also generated.Therefore, Cu content is set as being greater than 3.5% and is 8.0% or less.
Mo: greater than 2.0% and be 5.0% or less
Mo is the effective element for the corrosion resistance for ensuring austenite stainless steel.If make be more than 2.0% amount Mo contain together with the Cr of aforementioned quantities and Cu, then, can be to making the above-mentioned content of N in the environment of the condensation of the sulfuric acid of high concentration Austenite stainless steel assign good corrosion resistance.But if excessively containing Mo, hot-workability is reduced, especially It is Mo content if it exceeds 5.0%, even if then making the above-mentioned content of N, can also generates the obvious deterioration of hot-workability.Therefore, Mo Content is set as greater than 2.0% and is 5.0% or less.It should be noted that in order to true in the environment that the sulfuric acid of high concentration condenses Sufficient corrosion resistance is protected, the Mo of 3.0% amount is preferably contained more than.
Co:0.05% or less
Co is the element being contained in steel in the form of impurity.Co is the effective element for the toughness for improving steel, but It is expensive element, it is therefore not necessary to energetically add.Therefore, Co content is set as 0.05% or less.
Sn:0.05% or less
Sn is contained in steel in the form of impurity, due to that hot-workability can be made to deteriorate, content is preferably low as far as possible. Especially Sn content then will lead to the obvious deterioration of hot-workability if it exceeds 0.05%.Therefore, Sn content be set as 0.05% with Under.
V:0.5% or less
V has the function of fixing and improving corrosion resistance, especially improve resistance to grain boundary corrosion C, therefore, can basis It needs and contains.But content is if it exceeds 0.5%, even if then can also generate nitrogen in the case where making the above-mentioned content of N Compound, corrosion resistance reduce instead, in turn, also result in the deterioration of hot-workability.Therefore, V content is set as 0.5% or less.For Said effect is obtained, V content is preferably set to 0.01% or more.
Nb:0~1.0%
Nb has the function of fixing and improving corrosion resistance, especially improve resistance to grain boundary corrosion C, therefore, Ke Yigen Contain according to needs.But content is if it exceeds 1.0%, even if then can also be generated in the case where making the above-mentioned content of N Nitride, corrosion resistance reduce instead, in turn, also result in the deterioration of hot-workability.Therefore, Nb content is set as 1.0% or less. Said effect in order to obtain, Nb content are preferably set to 0.02% or more.
Ti:0~0.5%
Ti has the function of fixing and improving corrosion resistance, especially improve resistance to grain boundary corrosion C in the same manner as Nb, because This, can according to need and contain.But content is if it exceeds 0.5%, even if then in the case where making the above-mentioned content of N, Also nitride can be generated, corrosion resistance reduces instead, in turn, also results in the deterioration of hot-workability.Therefore, Ti content is set as 0.5% or less.Said effect in order to obtain, Ti content are preferably set to 0.01% or more.
W:0~5.0%
W have the function of improve high concentration sulfuric acid condensation in the environment of corrosion resistance, therefore, can according to need and Contain.But content if it exceeds 5.0%, then said effect is saturated, and only increases cost.Therefore, W content be set as 5.0% with Under.Said effect in order to obtain, W content are preferably set to 0.1% or more.
Zr:0~1.0%
Zr has the function of therefore the corrosion resistance in the environment of the sulfuric acid condensation of raising high concentration can according to need And contain.But content if it exceeds 1.0%, then said effect is saturated, and only increases cost.Therefore, Zr content is set as 1.0% or less.Said effect in order to obtain, Zr content are preferably set to 0.02% or more.
Al:0~0.5%
There is Al deoxidation therefore in the case where Si content is suppressed to extremely low, can also contain.But contain Amount is if it exceeds 0.5%, even if being then the austenite stainless steel for making the above-mentioned content of N, hot-workability can also be reduced.Cause This, Al content is set as 0.5% or less.The lower limit of Al content is not particularly limited, and can be the range of impurity.Wherein, by Si Content be suppressed to it is extremely low in the case where, preferably energetically add and it made to contain 0.02% or more, make deoxidation fully into Row.It should be noted that even if containing 0.05% or more Si, in order to give full play to deoxidation, it is also preferred that Al content is set as 0.01% or more.
Ca:0~0.01%
Ca has the effect of that hot-workability is inhibited to reduce in conjunction with S, therefore, can according to need and contain.But Content is if it exceeds 0.01%, then the cleannes of steel reduce, and can become the reason of generating defect when using the manufacture of heat.Cause This, Ca content is set as 0.01% or less.Said effect in order to obtain, Ca content are preferably set to 0.0005% or more, more preferably set It is 0.001% or more.
B:0~0.01%
B has the effect of therefore improving hot-workability can according to need and contain.But the excessive addition meeting of B The precipitation for promoting the Cr-B compound in crystal boundary, leads to the deterioration of corrosion resistance.The especially content of B if it exceeds 0.01%, The deterioration of apparent corrosion resistance can then be caused.Therefore, B content is set as 0.01% or less.Said effect in order to obtain, B content It is preferably set to 0.0005% or more, is more preferably set as 0.001% or more.
REM:0~0.01%
REM (rare earth element) has the function of therefore improving hot-workability can according to need and contain.But contain Amount is if it exceeds 0.01%, then the cleannes of steel reduce, and can become the reason of generating defect when using the manufacture of heat.Therefore, REM content is set as 0.01% or less.Said effect in order to obtain, REM content are preferably set to 0.0005% or more.
Herein, REM refers to 17 kinds of elements of total of Sc, Y and lanthanide series, and the content of REM refers to always containing for these elements Amount.
In the chemical composition of the base material of austenite stainless steel of the invention, surplus is Fe and impurity." impurity " herein Refer to: when industrial manufacture steel by the raw materials such as ore, waste material, manufacturing process various factors and mixed ingredient, and for not The ingredient allowed in the range of adverse effect is caused to the present invention.
3. about overlay film
As described above, overlay film is formed in at least part on surface possessed by base material.Moreover, in overlay film, relativity Ground improves the total content of Cr, Ni, Cu and Mo relative to Fe, so as to so that acid resistance greatly improves.
In particular, it is desirable to which there are Cr concentration to become maximum maximum Cr depth in overlay film, and make maximum Cr depth The chemical composition at place meets following formula (i).It, can be with it should be noted that the position of maximum Cr depth is not particularly limited It is present in the most surface layer of overlay film.
(Cr+Ni+Cu+Mo)/Fe≥1.0···(i)
Wherein, each element symbol in above-mentioned formula indicates the content (at%) of each element at steel surface.
In addition, overlay film of the invention essentially becomes the opposite enrichments such as layer and the Ni of the surface layer side comprising the opposite enrichment of Cr The structure of the layer of base material side.That is, that can have Cr concentration as the smallest minimum closer to base material side than above-mentioned maximum Cr depth Cr depth.
Moreover, the chemical composition of maximum Cr depth preferably satisfies following formula (ii), the chemical composition of minimum Cr depth Preferably satisfy following formula (iii).
Cr/(Ni+Cu+Mo)≥1.0···(ii)
Cr/(Ni+Cu+Mo)<1.0···(iii)
Wherein, each element symbol in above-mentioned formula indicates the content (at%) of each element.
For the thickness of overlay film, not especially setting limitation, such as the range of preferably 2~10nm.The thickness of overlay film is less than When 2nm, there is the worry for being unable to fully obtain corrosion resistance against sulfuric acid.On the other hand, the thickness of overlay film is if it exceeds 10nm, then have change The worry of the removing of the uneven and overlay film of overlay film composition must be easy to produce.
It should be noted that the chemical composition of overlay film is by utilizing X-ray photoelectron spectroscopy (XPS) in the present invention Depth analysis measures.By above-mentioned depth analysis, with the shape of shared ratio (at%) in the ingredient in addition to O, C and N The concentration curve of formula export each element.Then, it is determined that maximum Cr depth and minimum Cr depth, so as to find out each member of the depth The concentration of element calculates above-mentioned formula (i)~(iii) by these values.
In addition, the thickness of overlay film is found out by the concentration curve of O (oxygen).Specifically, by 1/ as the maximum concentration of O The position of 3 concentration is judged as the boundary portion of overlay film and base material, using the length until from overlay film surface to above-mentioned boundary portion as The thickness of overlay film.The measurement of composition and thickness about overlay film, it is generally desirable to be carried out in many places, using its average value.
4. manufacturing method
It for the manufacturing condition of austenite stainless steel of the invention, is not particularly limited, for example, can be to above-mentioned The steel blank of chemical composition implements heat treatment and acid processing under conditions of as shown below, to manufacture.
< heat treatment procedure >
For above-mentioned steel blank, firstly, implementing to keep within the temperature range of 1060~1140 DEG C at 60~600 seconds heat Reason.The oxidation overlay film based on Fe is formed on steel blank surface as a result,.When heat treatment temperature is less than 1060 DEG C, Fe oxidation is covered The formation of film becomes inadequate.On the other hand, heat treatment temperature is if it exceeds 1140 DEG C, then the grain coarsening of base material is big, Fe's Diffusion tails off, and therefore, Fe oxidation overlay film becomes unevenly, and then becomes easy and generate overlay film removing.As a result, above-mentioned any feelings Under condition, it is not likely to produce the enrichment of Cr, Ni, Cu and Mo.
< acid treatment process >
Then above-mentioned heat treatment implements acid processing to above-mentioned steel blank.In acid treatment process, melt Fe ingredient preferentially, So as to so that Cr, Ni, Cu and Mo are enriched in steel surface.In order to melt Fe ingredient preferentially, preferably in 30~50 DEG C, 5~8 bodies Product %HNO3, 5~8 volume %HF fluorine nitric acid in impregnate 1~5 hour.
Hereinafter, being more specifically illustrated according to embodiment to the present invention, but the present invention is not limited to these embodiments.
Embodiment
There is the steel (steel No.1~11) of chemical composition shown in table 1 with the VIM calciner melting of 3.5t, with common side Method is hot-forged, hot extrusion and cold-drawn, the steel pipe base of production outer diameter 75mm, wall thickness 3mm.Later, for testing the He of No.1~17 19~28, implement heat treatment and acid processing under the conditions shown in Table 2, austenite stainless steel pipe is made.In addition, for test No.18 grinds surface after implementing heat treatment and acid processing under the same conditions with test No.3.
[table 1]
[table 2]
Table 2
Then, pass through the chemical composition of overlay film that carries out being formed in each steel tube surface using XPS depth analysis and thickness Measurement.Specifically, with the concentration of the form export each element of shared ratio (at%) in the ingredient in addition to O, C and N Curve determines maximum Cr depth and minimum Cr depth, then finds out the concentration of each element of the depth.Then, by these values Calculate above-mentioned formula (i)~(iii).It should be noted that in the present embodiment, in the example in addition to testing No.18, maximum Cr depth It is present in the most surface layer of overlay film, in addition, in whole example, minimum Cr depth is present in than maximum Cr depth closer to base material side.
In addition, the thickness of overlay film is found out by the concentration curve of O (oxygen).Specifically, by 1/3 as the maximum concentration of O The position of concentration be judged as the boundary portion of overlay film and base material, using the length until from overlay film surface to above-mentioned boundary portion as covering The thickness of film.
In turn, in order to carry out the evaluation of corrosion resistance against sulfuric acid, the corrosion test in sulphuric acid environment is implemented.Corrosion test is logical Crossing makes to carry out in the solution that each steel pipe is impregnated in 100 DEG C of temperature and sulfuric acid concentration is 70%.Then, measurement dipping 8 hours Corrosion loss afterwards calculates the corrosion rate of per unit area.In the present invention, above-mentioned corrosion rate becomes 1.00g/ (m2·h) When following, it is judged as that corrosion resistance against sulfuric acid is excellent.
These results are shown in table 3 together.
[table 3]
As shown in Table 3, the test No.18 of the unsuitable test No.1,2 and 14~17 of manufacturing condition and lapped face In, do not generate the enrichment of Cr, Ni, Cu and Mo in overlay film, therefore, corrosion rate is high, becomes the result of corrosion resistance against sulfuric acid difference. Similarly, the Cu content in base material is unable to get acidproof brought by Cu in the test No.28 except restriction of the invention Property, and the enrichment of Cr, Ni, Cu and Mo in overlay film are insufficient, therefore, become the result of corrosion resistance against sulfuric acid difference.
In contrast, meet restriction of the invention and test No.3~13 that Cr, Ni, Cu and Mo are enriched in overlay film In 19~27, corrosion rate becomes 1.00g/ (m2H) hereinafter, becoming the excellent result of corrosion resistance against sulfuric acid.
Industrial availability
According to the present invention it is possible to obtain that there is excellent acid proof austenite in the environment of the condensation of the sulfuric acid of high concentration It is stainless steel.Therefore, austenite stainless steel of the invention can be used for heat exchange used in thermal power generation or industry boiler In the equipment used under flue gas desulfurization equipment component used in device, flue and chimney and various industries or sulphuric acid environment The various components such as the structural elements used.

Claims (3)

1. a kind of austenite stainless steel, has: base material and at least part for being formed in surface possessed by the base material Overlay film,
The chemical composition of the base material is calculated as with quality %
C:0.05% or less,
Si:1.0% or less,
Mn:2.0% or less,
P:0.040% or less,
S:0.010% or less,
O:0.020% or less,
N: less than 0.050%,
Ni:12.0~27.0%,
Cr:15.0% more than and less than 20.0%,
Cu: greater than 3.5% and for 8.0% or less,
Mo: greater than 2.0% and for 5.0% or less,
Co:0.05% or less,
Sn:0.05% or less,
V:0~0.5%,
Nb:0~1.0%,
Ti:0~0.5%,
W:0~5.0%,
Zr:0~1.0%,
Al:0~0.5%,
Ca:0~0.01%,
B:0~0.01%,
REM:0~0.01%,
Surplus: Fe and impurity,
The chemical composition that the Cr concentration of the overlay film becomes maximum maximum Cr depth meets following formula (i),
(Cr+Ni+Cu+Mo)/Fe≥1.0···(i)
Wherein, each element symbol in the formula indicates the content of each element, unit at%.
2. austenite stainless steel according to claim 1, wherein the chemical composition of the base material is contained in terms of quality % It is selected from
V:0.01~0.5%,
Nb:0.02~1.0%,
Ti:0.01~0.5%,
W:0.1~5.0%,
Zr:0.02~1.0%,
Al:0.01~0.5%,
Ca:0.0005~0.01%,
The and of B:0.0005~0.01%
REM:0.0005~0.01%
One or more of.
3. according to claim 1 or austenite stainless steel as claimed in claim 2, wherein the Cr concentration of the overlay film becomes The smallest minimum Cr depth is present in than the maximum Cr depth closer to the base material side,
The chemical composition of the maximum Cr depth meets following formula (ii), and the chemical composition of the minimum Cr depth meets Following formula (iii),
Cr/(Ni+Cu+Mo)≥1.0···(ii)
Cr/(Ni+Cu+Mo)<1.0···(iii)
Wherein, each element symbol in the formula indicates the content of each element, unit at%.
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH1018004A (en) * 1996-07-08 1998-01-20 Sumitomo Metal Ind Ltd Austenitic stainless steel excellent in sulfuric acid corrosion resistance
EP0971045A1 (en) * 1997-08-13 2000-01-12 Sumitomo Metal Industries Limited Austenitic stainless steel excellent in resistance to sulfuric acid corrosion and workability
JP2003213379A (en) * 2002-01-21 2003-07-30 Sumitomo Metal Ind Ltd Stainless steel having excellent corrosion resistance
CN104736735A (en) * 2012-10-30 2015-06-24 株式会社神户制钢所 Austenitic stainless steel

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU580758B2 (en) * 1984-03-16 1989-02-02 Inco Alloys International Inc. High-strength alloy for industrial vessels
JP2774709B2 (en) 1991-05-22 1998-07-09 日本冶金工業 株式会社 Sulfuric acid dew point corrosion resistant stainless steel with excellent hot workability
JPH11158584A (en) * 1997-11-27 1999-06-15 Sumitomo Metal Ind Ltd Austenitic stainless steel excellent in sulfuric acid corrosion resistance
JPH11189848A (en) * 1997-12-25 1999-07-13 Sumitomo Metal Ind Ltd Austenitic stainless steel excellent in sulfuric acid corrosion resistance
JP3294282B2 (en) 1998-08-10 2002-06-24 住友金属工業株式会社 Austenitic stainless steel with excellent sulfuric acid corrosion resistance and workability
JP2001107196A (en) * 1999-10-07 2001-04-17 Sumitomo Metal Ind Ltd Austenitic steel welded joint excellent in weld cracking resistance and sulfuric acid corrosion resistance and the welding material
JP3454216B2 (en) * 1999-12-24 2003-10-06 住友金属工業株式会社 Austenitic stainless steel
JP2002121655A (en) * 2000-10-18 2002-04-26 Nippon Steel Corp Stainless steel for crude phosphoric acid having excellent corrosion resistance

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH1018004A (en) * 1996-07-08 1998-01-20 Sumitomo Metal Ind Ltd Austenitic stainless steel excellent in sulfuric acid corrosion resistance
EP0971045A1 (en) * 1997-08-13 2000-01-12 Sumitomo Metal Industries Limited Austenitic stainless steel excellent in resistance to sulfuric acid corrosion and workability
JP2003213379A (en) * 2002-01-21 2003-07-30 Sumitomo Metal Ind Ltd Stainless steel having excellent corrosion resistance
CN104736735A (en) * 2012-10-30 2015-06-24 株式会社神户制钢所 Austenitic stainless steel

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