CN108368596A - With the corrosive ferritic stainless steel and its manufacturing method for automobile exhaust system of improved pitting corrosion resistance and resistance to condensate - Google Patents
With the corrosive ferritic stainless steel and its manufacturing method for automobile exhaust system of improved pitting corrosion resistance and resistance to condensate Download PDFInfo
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- CN108368596A CN108368596A CN201680072550.1A CN201680072550A CN108368596A CN 108368596 A CN108368596 A CN 108368596A CN 201680072550 A CN201680072550 A CN 201680072550A CN 108368596 A CN108368596 A CN 108368596A
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- C—CHEMISTRY; METALLURGY
- 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
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
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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
-
- 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
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- 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
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
-
- 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
- C22C38/28—Ferrous alloys, e.g. steel alloys containing chromium with titanium or zirconium
-
- 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
- C22C38/60—Ferrous alloys, e.g. steel alloys containing lead, selenium, tellurium, or antimony, or more than 0.04% by weight of sulfur
Abstract
It discloses with improved pitting corrosion resistance and the corrosive ferritic stainless steel and its manufacturing method for automobile exhaust system of resistance to condensate.By weight, the ferritic stainless steel of an embodiment according to the present invention includes 0.01% or smaller C, 0.5% to 1.0% Si, 0.5% or smaller Mn, 0.035% or smaller P, 0.01% or smaller S, 11% to 18% Cr, 0.013% or smaller N, 0.15% to 0.5% Ti, 0.03% to 0.5% Sb, and surplus is iron (Fe) and inevitable impurity, and surface portion is rich in the Sb of three times than base material.Therefore, it can be by with the amount of about 0.05% or bigger adding Sb and manufacturing with excellent pitting corrosion resistance and the corrosive ferritic stainless steel of resistance to condensate to being used as in a kind of 11Cr stainless steels STS 409 of conventional ferritic stainless steel, without increasing production cost and not reducing productivity.
Description
Technical field
The present invention relates to the corrosive iron element for automobile exhaust system of improved pitting corrosion resistance and resistance to condensate
Body stainless steel and its manufacturing method, and relate more particularly to such ferritic stainless steel for automobile exhaust system and its
Manufacturing method：It includes Sb and Sb is allowed to be enriched in the surface region of stainless steel to meet the characteristic needed for automobile exhaust system,
So that it is guaranteed that pitting corrosion resistance and the corrosion resistance in condensate atmosphere.
Background technology
Cold-rolling stainless steel product (especially cold rolling ferrite stainless steel product) has excellent hot properties, such as hot swollen
Swollen rate, thermal fatigue characteristics etc., and anticorrosion stress-resistant cracks.Therefore, ferritic stainless steel has been widely used in automobile exhaust
In the component of system, household equipment, structure, household electrical appliance, elevator etc..
In general, the component of automobile exhaust system is divided into thermal part and cold part according to the temperature of exhaust gas.The thermal part of automobile
Including exhaust manifold, converter and bellows, these components usually use under 600 DEG C or higher and have excellent high temperature
Intensity, thermal fatigue characteristics and salt corrosion characteristic.On the other hand, cold part is such component：It is used at about 400 DEG C, and
And include the silencer for reducing the noise caused by automobile exhaust.It is cold caused by sulphur (S) component in motor vehicle fuel
Condensate etching characteristic and by winter use deicer salts caused by outer surface corrosion characteristic, therefore such as stainless steel (or
STS) 409,409L, 439,436L and plate the material of al stainless steel 409 and have been used for the cold part of automobile exhaust system.
For example, material STS 409L generally the least expensive in stainless steel are one type of steel：It includes about 11 weight %
Cr and wherein C and N are stablized by Ti, are thus prevented the sensibility of welding region and are shown excellent machinability, are led to
It is often low at 700 DEG C or more to use, and to being had by resulting from the corrosion caused by the condensate component in automobile exhaust system
There is certain resistance, and therefore most widely used.
In the corrosive environment for needing highly corrosion resistant, be used for comprising 17 weight %Cr 439 steel of STS and
Include 439 steel of STS 436L steel and STS of about 1 weight %Mo, but there are problems that component costs increase.
Recently, in such as China, India and the drawing that automobile production and popularity rate sharply increase compared with other developed countries
In the country of man of the U.S., sulphur (S) content in gasoline is quite high.For example, South Korea provides that sulphur (S) content in gasoline is low with Japan
In 10ppm, China's regulation sulphur (S) content is less than 500ppm, but the gasoline of China includes to be higher than indeed according to area
The sulfur content of 500ppm.
Sulphur (S) in gasoline organizes sulfate ion (SO of the separating/enriching at the condensate component in automobile exhaust4 2-), and
Generate the sulfuric acid (H with pH 2 or smaller high corrosion characteristics2SO4) atmosphere.Due to this, routine possibly can not be used
STS 409L ensure corrosion resistance, and therefore gradually using such as STS 439 and 436L comprising 17 weight % or bigger
The high chromium class stainless steel material of Cr components or Mo.However, due to there are problems that the source price of material gradually increases, need
It develops not comprising high valence elements (such as Cr or Mo) or only to include those of very low amount element has a pitting corrosion resistance and resistance to
The corrosive stainless steel material of condensate.
(patent document 0001) Korean Unexamined Patent Application Publication the 10-2008-0110662nd
Invention content
Technical problem
The present invention relates to the ferritic stainless steels provided for automobile exhaust system, it includes Sb and Sb are allowed to be enriched in
The surface region of stainless steel is to meet the characteristic needed for automobile exhaust system, such as pitting corrosion resistance and resistance in condensate atmosphere
Corrosivity.
The invention further relates to the methods provided for manufacturing the ferritic stainless steel for automobile exhaust system.
Technical solution
According to an example of the present invention the ferritic stainless steel of property embodiment include C (0.01 weight % or smaller),
Si (0.5 weight % to 1.0 weight %), Mn (0.5 weight % or smaller), P (0.035 weight % or smaller), S (0.01 weights
Measure % or smaller), Cr (11 weight % to 18 weight %), N (0.013 weight % or smaller), Ti (0.15 weight % to 0.5 weight
Measure %), Sb (0.03 weight % to 0.5 weight %), Fe and inevitable impurity and Sb be with the amount of base material at least three times
It is enriched in the surface region of the stainless steel.
In addition, property embodiment, ferritic stainless steel may include 0.05 weight % to 0.5 according to an example of the present invention
The Sb of weight %.
In addition, property embodiment according to an example of the present invention, Sb can be enriched in stainless with the amount of at least seven times of base material
The surface region of steel.
In addition, property embodiment according to an example of the present invention, critical in the condensate solution of automobile exhaust system
Corrosion electric current density can be 5.5mA/m2Or smaller and spot corrosion potential can be 120mV or bigger.
Property embodiment according to an example of the present invention can pass through according to the method for manufacturing ferritic stainless steel
Hot rolling, thermal annealing, hot acid wash, cold rolling and final annealing are manufactured comprising ferritic stainless steel below：C (0.01 weight % or
Smaller), Si (0.5 weight % to 1.0 weight %), Mn (0.5 weight % or smaller), P (0.035 weight % or smaller), S
(0.01 weight % or smaller), Cr (11 weight % to 18 weight %), N (0.013 weight % or smaller), Ti (0.15 weight %
To 0.5 weight %), Sb (0.03 weight % to 0.5 weight %), Fe and inevitable impurity.
In addition, property embodiment, ferritic stainless steel can pass through conventional STS 409L works according to an example of the present invention
Skill manufactures.
Advantageous effect
Property embodiment according to an example of the present invention is not increasing production cost and is not reducing the feelings of machinability
Have excellent pitting corrosion resistance and resistance to condensate corrosivity ferritic stainless steel can be by into conventional ferritic stainless steel under condition
Existing 11Cr stainless steels such as STS 409 in add the Sb of about 0.05 weight % or bigger to manufacture.
In addition, ferritic stainless steel that ought be in accordance with an exemplary embodiment of the invention is used for the end of exhaust system,
Such as automobile exhaust system silencer associated materials when, such component of automobile exhaust system can be manufactured：It is really
Excellent corrosion resistance is protected, without increasing using the production cost in the area of conventional high-sulfur combustor (such as China).
Description of the drawings
Fig. 1 be show the addition Sb of the present invention stainless steel and stainless steel without Sb automobile exhaust system condensate
The figure of anode polarization characteristic in solution.
Fig. 2 be show the addition Sb of the present invention stainless steel and stainless steel without Sb automobile exhaust system condensate
The figure of critical current density in solution.
Fig. 3 be show the addition Sb of the present invention stainless steel and stainless steel without Sb automobile exhaust system condensate
The figure of spot corrosion characteristic in solution.
Fig. 4 be show the addition Sb of the present invention stainless steel and stainless steel without Sb automobile exhaust system condensate
The figure of spot corrosion potential in solution.
Fig. 5 is transmission electron microscope (TEM) image of the stainless steel of property embodiment according to an example of the present invention.
Fig. 6 is TEM mapping (mapping) images of the stainless steel of Fig. 5.
Fig. 7 shows the figure of energy dispersive spectrum (EDS) result in the Sb surface enrichments region of the stainless steel of Fig. 5.
Fig. 8 shows the figure of the EDS results in the base material region of the stainless steel of Fig. 5.
Fig. 9 is the TEM image of the stainless steel of property embodiment according to an example of the present invention.
Figure 10 is the TEM mapping images of the stainless steel of Fig. 9.
Figure 11 shows the figure of the EDS results in the first Sb surface enrichments region of the stainless steel for showing Fig. 9.
Figure 12 shows the figure of the EDS results in the 2nd Sb surface enrichments region of the stainless steel for showing Fig. 9.
Figure 13 shows the figure of the EDS results in the base material region for the stainless steel for showing Fig. 9.
Specific implementation mode
According to an example of the present invention the ferritic stainless steel of property embodiment include C (0.01 weight % or smaller),
Si (0.5 weight % to 1.0 weight %), Mn (0.5 weight % or smaller), P (0.035 weight % or smaller), S (0.01 weights
Measure % or smaller), Cr (11 weight % to 18 weight %), N (0.013 weight % or smaller), Ti (0.15 weight % to 0.5 weight
Measure %), Sb (0.03 weight % to 0.5 weight %), Fe and inevitable impurity, and wherein Sb is at least three times of base material
Amount be enriched in the surface region of the stainless steel.
Invention embodiment
Hereinafter, it will be described in detail with reference to the accompanying drawings the exemplary implementation scheme of the present invention.Following embodiment is provided to incite somebody to action this
The spirit of invention is fully conveyed to those of ordinary skill in the art.The present invention can carry out table with the different form being not described herein
Show, and is not limited to embodiment.For the sake of keeping the present invention clear, the explanation of the part unrelated with explanation will be omitted, and in order to help
Assistant solves, by the size of slightly amplifier unit.
Property embodiment according to an example of the present invention, the ferritic stainless steel for automobile exhaust system include C
(0.01 weight % or smaller), Si (0.5 weight % to 1.0 weight %), Mn (0.5 weight % or smaller), P (0.035 weight %
Or smaller), S (0.01 weight % or smaller), Cr (11 weight % to 18 weight %), N (0.013 weight % or smaller), Ti
(0.15 weight % to 0.5 weight %), Sb (0.03 weight % to 0.5 weight %), Fe and inevitable impurity.
C and N as Ti (C, N) carbonitride-forming elements with gap form in the presence of, when C and N content are high
When do not form Ti (C, N) carbonitride, and keep the elongation percentage of material and low-temperature impact property bad with C existing for high concentration and N
Change.When long period lowly uses material at 600 DEG C or more after welding, due to Cr23C6The generation of carbide and crystalline substance occurs
Between corrode, and the content of C is therefore preferably controlled to 0.01 weight % or smaller, and the content of N is preferably controlled to 0.01
Weight % or smaller.
In addition, when C+N contents are high, the steel-making field trash caused by the Ti by addition high-content increases, can
A large amount of surface defect (such as scab) can occur, occur nozzle blockage phenomenon in casting process, and due to the C of high-content and
N increases, therefore elongation percentage and impact characteristics reduce.Therefore, C+N contents are preferably controlled to 0.02 weight % or smaller.
Si is the element added as deoxidant element, and when its content increases as ferrite phase forming element, iron
Ferritic phase stability increases.When Si contents increase, spot corrosion potential increases, and inoxidizability increases.In the present invention, in order to
Spot corrosion potential and antioxidative purpose are improved, the Si of 0.5 weight % or more is preferably comprised at least.If Si contents increase to
1.0 weight % or bigger, then make steel the increase of Si field trashes and surface defect occurs.Therefore, Si contents are preferably controlled to not
More than 1.0 weight % or bigger.
When Mn contents increase, pitting corrosion resistance is reduced due to the formation of precipitate (such as MnS).However, excessive Mn
Reduction causes refining cost to increase, and therefore, and Mn contents are preferably controlled to 0.5 weight % or smaller.
Since P and S form cyrystal boundary segregation and MnS precipitates, hot-workability is caused to reduce, thus preferably exist a small amount of P and
S.However, causing refining cost to increase due to excessively reducing, P is preferably controlled to 0.035 weight % or smaller, and will
S is preferably controlled to 0.01 weight % or smaller.
Cr is for ensuring that the indispensable element of the corrosion resistance of stainless steel.It is resistance in condensate atmosphere when Cr contents are low
Corrosivity reduce, when Cr contents are too high, corrosion resistance improve, but due to high intensity, elongation percentage and impact characteristics reduce, with
And the production cost increases, therefore Cr contents are preferably controlled to 10 weight % to 18 weight %.
Ti is fixed C and N to prevent the effective element of intercrystalline corrosion.However, when Ti/ (C+N) is than reducing, due to occurring
In the intercrystalline corrosion of welding region, corrosion resistance reduces, and Ti is therefore preferably controlled at least 0.15 weight % or bigger.So
And when Ti contents are too high, steel-making field trash increases, since steel-making field trash increases, it is thus possible to a large amount of surface occurs and lack
It falls into (such as scab), nozzle blockage phenomenon occurs in casting process, and elongation percentage and impact characteristics reduce.Therefore, Ti is contained
Amount is preferably controlled to 0.5 weight % or smaller.
Sb is to ensure that the indispensable element for the pitting corrosion resistance and the corrosion resistance in condensate atmosphere that the present invention is intended to.
In the present invention, in order to ensure pitting corrosion resistance and resistance to condensate corrosivity, Sb is preferably controlled at least 0.03 weight
Measure % or bigger.However, since being excessively added for Sb causes manufacturing process to deteriorate, Sb contents are preferably controlled to 0.5 weight
Measure %.It is highly preferred that being 0.05 weight % to 0.5 weight % by the control of Sb contents.
The ferritic stainless steel of property embodiment can pass through the iron to including above-mentioned composition according to an example of the present invention
Ferritic stainless steel carries out hot rolling, thermal annealing, hot acid are washed, cold rolling and final annealing manufacture, and such manufacturing process can be with
It is conventional STS 409L manufacturing process.
In the ferritic stainless steel of property embodiment according to an example of the present invention, Sb is with the amount of base material at least three times
It is enriched in the surface region of stainless steel.For example, it is highly preferred that Sb is enriched in the surface of stainless steel with the amount of 7 times of base material or bigger
Region.Due to the opposite oxygen affinity for being better than other elements of oxygen affinity, so the formation that Sb is enriched in stainless steel has oxide skin
Surface region.
Since there are Sb rich regions for the surface region in stainless steel, with the ferrite not comprising the non-surface enrichments of Sb or Sb
Stainless steel is compared, and the stainless steel for adding Sb has the spot corrosion potential of the critical current density and raising that reduce, to it is expected
Pitting corrosion resistance and resistance to condensate corrosivity.
Fig. 1 be show the addition Sb of the present invention stainless steel and stainless steel without Sb automobile exhaust system condensate
The figure of anode polarization characteristic in solution.Fig. 2 be show the addition Sb of the present invention stainless steel and stainless steel without Sb in vapour
The figure of critical current density in the condensate solution of vehicle exhaust system.
In order to test the anode polarization characteristic in the condensate solution of automobile exhaust system, firstly, for including 11 weights
The high-purity ferritic stainless steel for measuring the Cr of %, will include the solution (sulphur of the solution of the condensate of replicar exhaust system
Acid (H2SO4)：5000ppm, sodium chloride (NaCl)：100ppm, pH：3.0) while being maintained at 30 DEG C, more of the invention adds
Add the anode polarization characteristic of the stainless steel of Sb and the stainless steel without Sb.
Referring to Fig.1, regardless of whether adding Sb into the stainless steel added with 11 weight %Cr, corrosion potential level is
About -500mV to -600mV, these are similar levels.However, compared with the stainless steel without Sb, the stainless steel tool of Sb is added
It is useful for the more low potential for causing to be converted to passive area from activating area.
With reference to Fig. 2, it can be seen that in activating area, add Sb stainless steel have it is lower than the stainless steel without Sb about
Twice of critical current density.
In addition, for the corrosion electric current density (passivation maintains current density) in passive area, the stainless steel of Sb is added
Current density is maintained with the passivation more slightly lower than the stainless steel without Sb, shows to be formed even more fine and close passivating film.Due to upper
State noble polarization curve characteristic, it may be determined that add the stainless steel of Sb comprising a large amount of Cl-Ion and SO4 2-The pH of ion is
There is excellent corrosion resistance in about 3 acid atmosphere.
For example, ferritic stainless steel can have 5.5mA/m in automobile exhaust system condensate solution2Or it is smaller critical
Corrosion electric current density.
Fig. 3 be show the addition Sb of the present invention stainless steel and stainless steel without Sb automobile exhaust system condensate
The figure of spot corrosion characteristic in solution.Fig. 4 is to show that the stainless steel of the addition Sb of the present invention and the stainless steel without Sb are arranged in automobile
The figure of spot corrosion potential in the condensate solution of gas system.
In order to assess pitting corrosion resistance, firstly, for the high-purity ferritic stainless steel for including 11 weight %Cr, will include
While the solution of 1%NaCl is maintained at 30 DEG C, the stainless steel of addition Sb more of the invention and the stainless steel without Sb
Spot corrosion characteristic.
With reference to Fig. 3 and 4, it can be seen that compared with the stainless steel without Sb, add Sb's into 11 weight %Cr stainless steels
Stainless steel has the spot corrosion potential for increasing about 13mV to 36mV.
For example, ferritic stainless steel can have 120mV or the spot corrosion potential of bigger.
It is found by above-mentioned noble polarization curve characteristic, under there are the etching condition of a large amount of sulphur component, adds Sb's
Stainless steel has better pitting corrosion resistance and resistance to condensate corrosivity.Herein, including 1%Cl-Ion and SO4 2-The pH of ion is
About 3 acid atmosphere more strongly reflects for example Chinese ground of sulphur component in the oil very high (that is, about 500ppm)
The etching condition of the silencer material of automobile exhaust system in area.
Hereinafter, the use of property embodiment according to an example of the present invention will in further detail be described with reference to embodiment
In the ferritic stainless steel of automobile exhaust system.
Embodiment
Invention steel 1
Pass through the ferrite stainless that in 50kg vacuum melting furnaces prepared by the composition of invention steel 1 shown in fusing the following table 1
Steel manufactures the ingot casting of 120mm thickness.The hot steel plates of 3.0mmt are manufactured by hot rolling manufactures as described above at 1150 DEG C ingot casting.
By being annealed to hot steel plate, pickling and cold rolling manufacture the cold steel plates of 1.2mmt, be then subjected to final annealing and pickling,
Thus ferrite stainless steel product is manufactured.
Invention steel 2
Ferrite stainless steel product is manufactured by the identical method with described in invention steel 1, the difference is that：Under use
The composition of invention steel 2 shown in table 1.
Invention steel 3
Ferrite stainless steel product is manufactured by the identical method with described in invention steel 1, the difference is that：Under use
The composition of invention steel 3 shown in table 1.
Comparative example
Compare steel 1
Ferrite stainless steel product is manufactured by the identical method with described in invention steel 1, the difference is that：Under use
Compare the composition of steel 1 shown in table 1.
Compare steel 2
Ferrite stainless steel product is manufactured by the identical method with described in invention steel 1, the difference is that：Under use
Compare the composition of steel 2 shown in table 1.
[table 1]
The following table 2 shows to measure critical current density according to invention steel and the stainless steel for comparing steel making and spot corrosion potential
As a result.
[table 2]
In order to assess corrosion resistance, by analyzing the condensate component in the automotive muffler of the China using high-sulfur combustor
Including Cl at 30 DEG C-Concentration：100ppm and SO4 2-Concentration：The anode polarization of stainless steel is measured in the aqueous solution of 5000pmm
Characteristic.After a test, corrosion resistance is assessed with critical point corrosion current density in activating area.In addition, being wrapped at 30 DEG C
Containing 1%Cl-Solution in measure pitting corrosion resistance.In addition, in stainless steel, the Sb that base material and Sb enriched layers are analyzed by EDS contains
Amount.
Fig. 5 is the TEM image of the stainless steel of invention steel 2 according to the present invention.Fig. 6 is the TEM mapping graphs of the stainless steel of Fig. 5
Picture.Fig. 7 shows the figure of the EDS results in the Sb surface enrichments region of the stainless steel of Fig. 5.Fig. 8 shows the base material area of the stainless steel of Fig. 5
The figure of the EDS results in domain.
With reference to the composition of the key component of the analysis surface rich regions 1 of Fig. 7 and 8 and base material, and it is shown in table 3.
[table 3]
With reference to Fig. 5 to 8, it can be seen that at the surface region of the stainless steel of invention steel 2 according to the present invention, Sb enrichments
Region (surface enrichment region 1) is formed as adjacent with base material region.As shown in table 2, it can be seen that invention steel 2 have frequently compared with
The lower critical current density of steel and higher spot corrosion potential.
Fig. 9 is the TEM image of the stainless steel of property embodiment according to an example of the present invention.Figure 10 is the stainless of Fig. 9
The TEM of steel maps image.Figure 11 shows the figure of the EDS results of the first surface Sb rich regions for the stainless steel for showing Fig. 9.Figure
12 show the figure of the EDS results of the second surface Sb rich regions for the stainless steel for showing Fig. 9.Figure 13, which is shown, shows Fig. 9's
The figure of the EDS results in the base material region of stainless steel.
The composition of the key component of 2 and 13 analysis surface rich region 2A, surface enrichment region 2B and base material referring to Fig.1.
As a result it is shown in table 4.
[table 4]
With reference to Fig. 9 to 13, it can be seen that at the surface region of the stainless steel of invention steel 3 according to the present invention, Sb enrichments
(surface enrichment region 2A and surface enrichment region 2B) is formed as adjacent with base material region in region.As shown in table 2, it can be seen that
Invention steel 3 has frequently compared with the lower critical current density of steel and higher spot corrosion potential.
Although as described above, describing the present invention with reference to the exemplary implementation scheme of the present invention, the present invention is unlimited
In this, and it will be recognized by one of ordinary skill in the art that various modifications can be carried out and changes without departing from appended claims
Concept and range.
Industrial applicibility
In accordance with an exemplary embodiment of the invention there is improved pitting corrosion resistance and resistance to condensate is corrosive is used for
The ferritic stainless steel and its manufacturing method of automobile exhaust system can be applied to the component of automobile exhaust system.
Claims (6)
1. a kind of having improved pitting corrosion resistance and the corrosive ferritic stainless steel for automobile exhaust system of resistance to condensate,
Including：
C：0.01 weight % or smaller, Si：0.5 weight % to 1.0 weight %, Mn：0.5 weight % or smaller, P：0.035 weight
Measure % or smaller, S：0.01 weight % or smaller, Cr：11 weight % to 18 weight %, N：0.013 weight % or smaller, Ti
0.15 weight % to 0.5 weight %, Sb：0.03 weight % to 0.5 weight %, Fe and inevitable impurity,
Wherein Sb is enriched in the surface region of the stainless steel with the amount of base material at least three times.
2. ferritic stainless steel according to claim 1, wherein Sb are comprised in 0.05 weight % to 0.5 weight %
It is interior.
3. ferritic stainless steel according to claim 1, wherein Sb are enriched in described stainless with the amount of at least seven times of base material
The surface region of steel.
4. ferritic stainless steel according to claim 1 has in the condensate solution of automobile exhaust system
5.5mA/m2Or the spot corrosion potential of smaller critical point corrosion current density and 120mV or bigger.
5. a kind of for manufacturing with the corrosive iron element for automobile exhaust system of improved pitting corrosion resistance and resistance to condensate
The method of body stainless steel, including：
It is washed by hot rolling, thermal annealing, hot acid, cold rolling and final annealing are manufactured comprising ferritic stainless steel below：C：0.01
Weight % or smaller, Si：0.5 weight % to 1.0 weight %, Mn：0.5 weight % or smaller, P：0.035 weight % or smaller,
S：0.01 weight % or smaller, Cr：11 weight % to 18 weight %, N：0.013 weight % or smaller, 0.15 weight % of Ti are extremely
0.5 weight %, Sb：0.03 weight % to 0.5 weight %, Fe and inevitable impurity.
6. according to the method described in claim 5, the wherein described ferritic stainless steel by conventional STS 409L manufacturing process come
Manufacture.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020150182709A KR102047401B1 (en) | 2015-12-21 | 2015-12-21 | Ferritic stainless steel for automotive exhaust system with improved pitting corrosion resistance and corrosion resistance for water condensation and method of manufacturing the same |
| KR10-2015-0182709 | 2015-12-21 | ||
| PCT/KR2016/014951 WO2017111436A1 (en) | 2015-12-21 | 2016-12-20 | Ferritic stainless steel for automotive exhaust system, having improved pitting corrosion resistance and condensate corrosion resistance, and method for manufacturing same |
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| Publication Number | Publication Date |
|---|---|
| CN108368596A true CN108368596A (en) | 2018-08-03 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201680072550.1A Pending CN108368596A (en) | 2015-12-21 | 2016-12-20 | With the corrosive ferritic stainless steel and its manufacturing method for automobile exhaust system of improved pitting corrosion resistance and resistance to condensate |
Country Status (4)
| Country | Link |
|---|---|
| KR (1) | KR102047401B1 (en) |
| CN (1) | CN108368596A (en) |
| MX (1) | MX2018007201A (en) |
| WO (1) | WO2017111436A1 (en) |
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| KR20190061516A (en) * | 2017-11-28 | 2019-06-05 | 주식회사 포스코 | Ferritic stainless steel for automotive exhaust system having excellent corrosion resistance to sulfuric acid and method for manufacturing the same |
| KR102424980B1 (en) * | 2020-11-19 | 2022-07-25 | 주식회사 포스코 | Ferritic stainless steel with improved strength, workability and corrosion resistance |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005146345A (en) * | 2003-11-14 | 2005-06-09 | Nippon Steel & Sumikin Stainless Steel Corp | Ferritic stainless steel superior in oxidation resistance |
| CN101437974A (en) * | 2006-05-09 | 2009-05-20 | 新日铁住金不锈钢株式会社 | Stainless steel excellent in corrosion resistance, ferritic stainless steel excellent in resistance to crevice corrosion and formability, and ferritic stainless steel excellent inresistance to crevice |
| JP2010031315A (en) * | 2008-07-28 | 2010-02-12 | Nippon Steel & Sumikin Stainless Steel Corp | Low alloy type ferritic stainless steel for automotive exhaust system member having excellent corrosion resistance after heating |
| KR20140080350A (en) * | 2012-12-20 | 2014-06-30 | 주식회사 포스코 | Ferritic stainless steel sheet and manufacturing method thereof |
| WO2015037707A1 (en) * | 2013-09-13 | 2015-03-19 | 新日鐵住金ステンレス株式会社 | Inexpensive automotive member and feed oil pipe, exhibiting excellent salt corrosion resistance |
| CN104870674A (en) * | 2012-12-24 | 2015-08-26 | Posco公司 | Ferritic stainless steel for automotive exhaust system, which have excellent corrosion resistance against condensate, moldability, and high-temperature oxidation resistance, and method for manufacturing same |
| CN104878322A (en) * | 2015-05-14 | 2015-09-02 | 中天钢铁集团有限公司 | Production technology of low-carbon weather-resistant steel |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| JP4727601B2 (en) | 2007-02-06 | 2011-07-20 | 新日鐵住金ステンレス株式会社 | Ferritic stainless steel with excellent crevice corrosion resistance |
| JP5320034B2 (en) * | 2008-11-14 | 2013-10-23 | 新日鐵住金ステンレス株式会社 | Mo-type ferritic stainless steel for automotive exhaust system parts with excellent corrosion resistance after heating |
| KR101174998B1 (en) * | 2010-07-28 | 2012-08-17 | 현대제철 주식회사 | Apparatus for measuring friction factor of a steel sheet |
| KR101485641B1 (en) | 2012-12-24 | 2015-01-22 | 주식회사 포스코 | Ferritic stainless steel for automotive exhaust system with excellent corrosion resistance for water condensation and formability and the method of manufacturing the same |
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Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005146345A (en) * | 2003-11-14 | 2005-06-09 | Nippon Steel & Sumikin Stainless Steel Corp | Ferritic stainless steel superior in oxidation resistance |
| CN101437974A (en) * | 2006-05-09 | 2009-05-20 | 新日铁住金不锈钢株式会社 | Stainless steel excellent in corrosion resistance, ferritic stainless steel excellent in resistance to crevice corrosion and formability, and ferritic stainless steel excellent inresistance to crevice |
| JP2010031315A (en) * | 2008-07-28 | 2010-02-12 | Nippon Steel & Sumikin Stainless Steel Corp | Low alloy type ferritic stainless steel for automotive exhaust system member having excellent corrosion resistance after heating |
| KR20140080350A (en) * | 2012-12-20 | 2014-06-30 | 주식회사 포스코 | Ferritic stainless steel sheet and manufacturing method thereof |
| CN104870674A (en) * | 2012-12-24 | 2015-08-26 | Posco公司 | Ferritic stainless steel for automotive exhaust system, which have excellent corrosion resistance against condensate, moldability, and high-temperature oxidation resistance, and method for manufacturing same |
| WO2015037707A1 (en) * | 2013-09-13 | 2015-03-19 | 新日鐵住金ステンレス株式会社 | Inexpensive automotive member and feed oil pipe, exhibiting excellent salt corrosion resistance |
| CN104878322A (en) * | 2015-05-14 | 2015-09-02 | 中天钢铁集团有限公司 | Production technology of low-carbon weather-resistant steel |
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| KR102047401B1 (en) | 2019-11-25 |
| KR20170074260A (en) | 2017-06-30 |
| WO2017111436A1 (en) | 2017-06-29 |
| MX2018007201A (en) | 2018-12-11 |
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