WO2014087648A1 - Ferritic stainless steel sheet - Google Patents
Ferritic stainless steel sheet Download PDFInfo
- Publication number
- WO2014087648A1 WO2014087648A1 PCT/JP2013/007124 JP2013007124W WO2014087648A1 WO 2014087648 A1 WO2014087648 A1 WO 2014087648A1 JP 2013007124 W JP2013007124 W JP 2013007124W WO 2014087648 A1 WO2014087648 A1 WO 2014087648A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- less
- amount
- stainless steel
- steel sheet
- range
- Prior art date
Links
Classifications
-
- 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
-
- 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
- C21D6/00—Heat treatment of ferrous alloys
- C21D6/002—Heat treatment of ferrous alloys containing Cr
-
- 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
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/46—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals
-
- 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
- C22C38/001—Ferrous alloys, e.g. steel alloys containing N
-
- 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
- C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
-
- 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
- C22C38/004—Very low carbon steels, i.e. having a carbon content of less than 0,01%
-
- 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
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
-
- 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
- C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
-
- 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
- C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
-
- 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
- C22C38/46—Ferrous alloys, e.g. steel alloys containing chromium with nickel with vanadium
-
- 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
- C22C38/48—Ferrous alloys, e.g. steel alloys containing chromium with nickel with niobium or tantalum
-
- 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
- C22C38/54—Ferrous alloys, e.g. steel alloys containing chromium with nickel with boron
-
- 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
- C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
- C21D8/0226—Hot rolling
-
- 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
- C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
- C21D8/0236—Cold rolling
-
- 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
- C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
- C21D8/0263—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment following hot rolling
-
- 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
- C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
- C21D8/0273—Final recrystallisation annealing
Definitions
- the present invention relates to a ferritic stainless steel sheet, and particularly to a ferritic stainless steel sheet having excellent surface properties.
- Stainless steel sheets are roughly classified into ferritic stainless steel sheets represented by SUS430 and austenitic stainless steel sheets represented by SUS304.
- Ferritic stainless steel sheets have a smaller thermal expansion coefficient and higher thermal conductivity than austenitic stainless steel sheets. For this reason, the ferritic stainless steel sheet is excellent in thermal fatigue characteristics. In addition, stress corrosion cracking resistance is less likely to occur.
- Ferritic stainless steel sheets with these properties are used in automotive exhaust systems that require excellent thermal fatigue properties in addition to heat resistance and oxidation resistance, and excellent stress corrosion cracking resistance. It is applied to kitchen facilities and electric water heaters that require high power.
- ferritic stainless steel sheets have the great advantage that they can be manufactured at a low cost because they contain less expensive elements such as Ni and Mn, which are austenite-forming elements. Have. These excellent properties have been evaluated, and ferritic stainless steel sheets have been applied to various applications, and their needs have been increasing in recent years.
- the ferritic stainless steel sheet applied for such applications is required to have not only the above properties but also excellent surface properties.
- Patent Document 1 discloses a technique for reducing the generation of TiN inclusions by regulating the amounts of Ti, N, and O.
- Patent Document 1 discloses a technique for reducing the generation of TiN inclusions by regulating the amounts of Ti, N, and O.
- the surface texture may deteriorate, and an excellent surface texture cannot be obtained only by component regulation considering only oxides and nitrides.
- the present invention has been made to solve the above-described problems, and an object thereof is to provide a ferritic stainless steel sheet having excellent surface properties.
- the present inventors investigated the types of inclusions generated in the ferritic stainless steel sheet and the amount of the inclusions.
- coarse Ti-based sulfides and Ti-based phosphides Ti-based oxides.
- Phosphide was also produced, and it was revealed that this coarse Ti-based sulfide and phosphide deteriorated the surface properties of the steel sheet.
- the present inventors then studied diligently about the steel plate component range in which the surface properties do not deteriorate due to Ti-based oxides, sulfides and phosphides. As a result, it has been found that by appropriately managing the amounts of Ti, S, P, and O, the formation of the inclusions can be suppressed, and the surface properties of the steel sheet are greatly improved.
- the present invention has been made based on the above findings, and the gist thereof is as follows. [1] By mass%, C: 0.004% to 0.014%, N: 0.004% to 0.014%, Si: 0.01% to 0.30%, Mn: 0.00.
- a ferritic stainless steel sheet having excellent surface properties can be obtained.
- the present invention provides a technology for obtaining a ferritic stainless steel sheet having excellent surface properties by effectively suppressing the formation of Ti-based sulfides and phosphides, which have not been considered in the past, in addition to Ti-based oxides.
- Ti-based sulfides and phosphides which have not been considered in the past, in addition to Ti-based oxides.
- regulated the component composition of the steel plate of this invention below is demonstrated.
- all the component% means the mass% unless there is particular notice.
- C 0.004% or more and 0.014% or less
- the amount of C exceeds 0.014%, the workability is deteriorated and the corrosion resistance of the welded part is significantly lowered when welding is performed.
- a lower C content is preferable from the viewpoint of corrosion resistance and workability.
- the C content is in the range of 0.004% to 0.014%.
- it is 0.004% or more and 0.011% or less of range. More preferably, it is 0.005% or more and 0.008% or less of range.
- the N amount is set in the range of 0.004% to 0.014%.
- the N amount is set in the range of 0.004% or more and 0.011% or less of range. More preferably, it is 0.006% or more and 0.009% or less of range.
- Si 0.01% or more and 0.30% or less Si is an element useful as a deoxidizer in the steelmaking process. This effect can be obtained by making the Si amount 0.01% or more. The effect increases as the Si amount increases. However, if the amount of Si exceeds 0.30%, the rolling load in the hot rolling process increases and the productivity decreases, and a large amount of oxide scale is generated on the surface, resulting in an increase in surface defects. Therefore, it is not preferable. Therefore, the Si amount is set to 0.01% or more and 0.30% or less. In order to perform descaling more easily in the annealing / pickling process, the Si content is preferably 0.25% or less. More preferably, it is 0.20% or less.
- Mn 0.01% or more and 0.30% or less Mn has an effect of increasing the strength of the steel sheet, and is also an element useful as a deoxidizer. In order to acquire these effects, it is necessary to make Mn amount 0.01% or more. However, if the amount of Mn exceeds 0.30%, the thickness of the oxide scale generated in the annealing process of the hot-rolled sheet or the annealing process of the cold-rolled sheet becomes thick, and the surface properties are lowered. Therefore, the amount of Mn is 0.01% or more and 0.30% or less. Preferably it is 0.05 to 0.25% of range. More preferably, it is 0.05 to 0.20% of range.
- P 0.025% or more and 0.040% or less
- P is an element inevitably contained in the steel sheet. Further, excessive P content reduces weldability and easily causes intergranular corrosion. This tendency becomes remarkable when the amount of P exceeds 0.040%. A lower P content is preferable from the viewpoint of weldability and prevention of intergranular corrosion.
- the P content is in the range of 0.025% to 0.040%. Preferably, it is 0.025% or more and 0.035% or less. More preferably, it is 0.025% or more and 0.030% or less.
- S 0.010% or less S, like P, is an element inevitably contained in the steel sheet.
- the S amount is 0.010% or less.
- it is 0.007% or less. More preferably, it is 0.004% or less.
- Al 0.01% or more and 0.08% or less
- Al is an effective deoxidizer. This effect as a deoxidizer can be obtained by making the Al content 0.01% or more. However, if the amount of Al exceeds 0.08%, surface defects due to Al-based inclusions may occur, and pickling properties in the annealing process are deteriorated, which is not preferable in production. Therefore, the Al content is set in a range of 0.01% to 0.08%. Preferably it is 0.01% or more and 0.06% or less of range. More preferably, it is 0.02% or more and 0.05% or less.
- the Cr content is in the range of 10.5% or more and 24.0% or less.
- the Cr content is 12.0% or more and 24.0% or less of range. More preferably, it is 15.0% or more and 21.5% or less of range. Even more preferably, it is in the range of 16.0% or more and 19.0% or less.
- Ni 0.01% or more and 0.40% or less
- Ni is an element that improves the corrosion resistance of a stainless steel plate, and the progress of corrosion in a corrosive environment where a passive film cannot be formed and active dissolution occurs. It is an element which suppresses. This effect is obtained by setting the Ni content to 0.01% or more, and increases as the Ni content increases. However, when the Ni content exceeds 0.40%, workability is lowered and stress corrosion cracking is likely to occur. Furthermore, since Ni is an expensive element, an increase in the amount of Ni causes an increase in manufacturing cost, which is not preferable. Therefore, the Ni content is 0.01% or more and 0.40% or less. Preferably it is 0.05 to 0.30% of range. More preferably, it is 0.10% or more and 0.20% or less of range.
- Ti 0.20% or more and 0.38% or less Ti combines with C or N to improve workability or prevent the weld from becoming sensitized and improve the corrosion resistance of the weld. In order to obtain this effect, the Ti amount needs to be 0.20% or more. However, if the amount of Ti exceeds 0.38%, coarse Ti carbonitride is generated in the casting process and causes surface defects, which is not preferable. Therefore, the Ti amount is set to 0.20% or more and 0.38% or less. Preferably it is 0.20% or more and 0.35% or less of range. More preferably, it is 0.25% or more and 0.35% or less of range.
- Nb 0.012% or less If the Nb content exceeds 0.012%, the recrystallization temperature rises, and good mechanical properties are achieved unless the annealing temperature of the hot-rolled sheet or the annealing temperature of the cold-rolled sheet is increased. Cannot be obtained. When these annealing temperatures are raised, the scale generated during annealing becomes thicker. Therefore, some scales remain after pickling, or the surface is roughened by performing strong pickling to remove thick scales, and the surface properties are deteriorated. Therefore, the Nb content is 0.012% or less. Preferably it is 0.008% or less. More preferably, it is 0.005% or less.
- O 0.0060% or less
- O is an element that improves the penetration depth during welding. However, if the amount of O exceeds 0.0060%, the amount of oxide inclusions increases and the corrosion resistance decreases. Therefore, the O amount is set to 0.0060% or less. Preferably it is 0.0045% or less. More preferably, it is 0.0030% or less.
- (P% + S% + 10 ⁇ O%) ⁇ Ti% ⁇ 0.025 Ti forms inclusions with P, S and O.
- (P% + S% + 10 ⁇ O%) ⁇ Ti% exceeds 0.025 the amount of Ti-based inclusions generated on the steel sheet surface increases and the inclusions become coarse, resulting in a decrease in surface defects and surface gloss. Since surface quality deteriorates, it is not preferable. Further, if (P% + S% + 10 ⁇ O%) ⁇ Ti% exceeds 0.025, it is preferable because coarse Ti-based inclusions generated on the surface of the steel sheet cause defects in the passive film and decrease the corrosion resistance. Absent. Therefore, (P% + S% + 10 ⁇ O%) ⁇ Ti% is set to 0.025 or less. P%, S%, 0%, and Ti% represent the contents (mass%) of P, S, O, and Ti, respectively.
- the ferritic stainless steel sheet of the present invention contains the above-mentioned essential components, and the balance consists of Fe and inevitable impurities.
- ferritic stainless steel sheet of the present invention is further optionally selected from one or more selected from Cu, Mo and V, and from Zr, REM, W, Co, B, Mg and Ca. 1 type (s) or 2 or more types selected can be contained within the following range.
- Cu is an element that improves corrosion resistance.
- Cu is an element particularly effective for improving the corrosion resistance of the base material and the weld when the steel plate is in an aqueous solution or when weakly acidic water droplets adhere to the steel plate. This effect is obtained by making Cu 0.01% or more, and the effect becomes higher as the amount of Cu increases.
- the amount of Cu exceeds 0.48%, hot workability is deteriorated, and an oxide derived from Cu called red scale is formed on the slab during hot rolling, resulting in surface defects. Therefore, it is not preferable.
- the amount of Cu shall be 0.01% or more and 0.48% or less.
- it is 0.10% or more and 0.48% or less of range. More preferably, it is 0.30% or more and 0.45% or less of range.
- Mo 0.01% or more and 1.20% or less
- Mo is an element that remarkably improves the corrosion resistance of the stainless steel plate. This effect is obtained by setting the Mo amount to 0.01% or more, and the effect increases as the Mo amount increases. However, if the Mo content exceeds 1.20%, the hot workability is deteriorated and surface defects frequently occur during hot rolling. Moreover, since Mo is an expensive element, the addition of a large amount increases the manufacturing cost. Therefore, when adding Mo, the amount of Mo shall be 0.01% or more and 1.20% or less. Preferably it is 0.30% or more and 1.20% or less of range. More preferably, it is 0.30% or more and 0.90% or less of range. More preferably, it is 0.40% or more and 0.60% or less of range.
- V 0.01% or more and 0.10% or less
- V is an element effective for refining crystal grains after annealing, preventing surface deteorations and improving fatigue characteristics. Further, V is combined with C or N and has an effect of suppressing a decrease in corrosion resistance due to the sensitization of the welded portion. These effects can be obtained by making the V amount 0.01% or more. However, if the V amount exceeds 0.10%, the workability is lowered and the raw material cost is increased, which is not preferable. Therefore, when adding V, the amount of V is made 0.01% or more and 0.10% or less. Preferably it is 0.01% or more and 0.07% or less of range. More preferably, it is 0.02% or more and 0.05% or less.
- Zr combines with C and N to sensitize welds Has the effect of increasing the high temperature strength. These effects can be obtained by making the amount of Zr 0.01% or more. On the other hand, if the amount of Zr exceeds 0.20%, workability deteriorates. Moreover, since Zr is an expensive element, excessive addition causes an increase in manufacturing cost, which is not preferable. Therefore, when adding Zr, the amount of Zr shall be 0.01% or more and 0.20% or less. Preferably, the range is 0.01% or more and 0.10% or less.
- REM 0.001% or more and 0.100% or less REM has the effect of improving oxidation resistance, and in particular, suppresses the formation of an oxide film on the weld and improves the corrosion resistance of the weld. effective.
- the REM amount needs to be 0.001% or more.
- the amount of REM shall be 0.001% or more and 0.100% or less.
- it is set as 0.001% or more and 0.050% or less of range.
- W 0.01% or more and 0.20% or less W, like Mo, has the effect of improving the corrosion resistance. This effect can be obtained by making the W amount 0.01% or more.
- the amount of W exceeds 0.20%, the strength increases, and the productivity is lowered due to an increase in rolling load or the like, which is not preferable.
- the W content is in the range of 0.01% to 0.20%.
- the range is 0.01% or more and 0.10% or less.
- Co 0.01% or more and 0.20% or less
- Co is an element that improves toughness. This effect can be obtained by making the Co content 0.01% or more.
- the amount of Co exceeds 0.20%, workability deteriorates. Therefore, when adding Co, the amount of Co is set to a range of 0.01% or more and 0.20% or less. Preferably, the range is 0.01% or more and 0.10% or less.
- B 0.0002% or more and 0.0020% or less B is an element effective for improving resistance to secondary working embrittlement after deep drawing. This effect can be obtained by making the B amount 0.0002% or more. On the other hand, if the amount of B exceeds 0.0020%, the rolling load during hot rolling increases and surface defects increase, which is not preferable. Therefore, when adding B, the amount of B is made into the range of 0.0002% or more and 0.0020% or less. Preferably it is 0.0005% or more and 0.0015% or less of range.
- Mg 0.0002% or more and 0.0010% or less
- Mg is an element that improves the rate of equiaxed crystals of the slab and is effective in improving workability and toughness. Furthermore, in a steel sheet containing Ti as in the present invention, the toughness decreases when the Ti carbonitride becomes coarse, but Mg also has an effect of suppressing the coarsening of the Ti carbonitride. These effects can be obtained by setting the Mg amount to 0.0002% or more. On the other hand, if the amount of Mg exceeds 0.0010%, the amount of Mg inclusions increases and the surface properties of the steel sheet are deteriorated. Therefore, when adding Mg, the amount of Mg is set in the range of 0.0002% to 0.0010%. Preferably it is 0.0002% or more and 0.0004% or less of range.
- Ca 0.0005% or more and 0.0030% or less
- Ca is an effective component for preventing the choke of nozzle due to precipitation of Ti inclusions which are likely to occur during continuous casting. The effect is acquired by making Ca amount 0.0005% or more. However, if the Ca content exceeds 0.0030%, the corrosion resistance decreases due to the formation of CaS. Therefore, when Ca is added, the Ca content is in the range of 0.0005% to 0.0030%. Preferably it is 0.0005% or more and 0.0020% or less of range. More preferably, it is 0.0005% or more and 0.0015% or less of range.
- the ferritic stainless steel sheet of the present invention is obtained by melting a molten steel having the above composition by a known method such as a converter, an electric furnace, a vacuum melting furnace or the like, and continuously casting or ingot-and-bloomig method.
- Steel material (slab). The slab is heated at 1100 to 1250 ° C. for 1 to 24 hours, or directly hot-rolled as cast without heating to form a hot-rolled sheet.
- hot-rolled sheets are subjected to continuous annealing at 800 to 1100 ° C. and batch-annealing hot-rolled sheets at 700 to 900 ° C.
- the hot-rolled sheet after annealing or the unrolled hot-rolled sheet is subjected to pickling and cold rolling to become a cold-rolled sheet.
- the cold-rolled sheet is annealed and pickled to become a product.
- Cold rolling is preferably performed at a rolling reduction of 50% or more from the viewpoints of ductility, bendability, press formability, and leveling.
- the recrystallization annealing of cold-rolled sheets is generally performed according to JIS G 0203 surface finish, No. In the case of a 2B finished product, it is preferable to carry out at 800 to 1000 ° C. in view of obtaining good mechanical properties and pickling properties. In order to obtain more gloss, BA annealing (bright annealing) may be performed.
- grinding or polishing may be performed.
- a stainless steel plate having the chemical composition shown in Table 1 (the essential components are shown in Table 1-1 and the optional components are shown in Table 1-2) was melted in a 50 kg small vacuum melting furnace. These steel ingots were heated to 1150 ° C. and then hot-rolled to obtain 3.5 mm thick hot rolled sheets. Subsequently, the hot-rolled sheet obtained above was annealed at 950 ° C. for 10 minutes, then shot blasted, pickled with a mixed acid of hydrofluoric acid and nitric acid, and cold-rolled to a thickness of 0.8 mm. Cold-rolled sheet was used. The obtained cold-rolled sheet was subjected to finish annealing at 900 ° C. in an air atmosphere, and then pickled with a mixed acid of hydrofluoric acid and nitric acid.
- salt spray cycle test The corrosion resistance of the cold-rolled annealed pickling plates obtained as described above was evaluated by visual inspection and a salt spray cycle test.
- salt spray (5% NaCl, 35 ° C., spray 2 h) ⁇ dry (60 ° C., 4 h, relative humidity 40%) ⁇ wet (50 ° C., 2 h, relative humidity ⁇ 95%) is one cycle. Five cycles were performed.
- Table 2 shows the results obtained as described above.
- Comparative Example B1 in which the Cr content is less than the range of the present invention although the predetermined surface quality was obtained, corrosion occurred on the entire surface of the test piece in the salt spray cycle test, and sufficient corrosion resistance was not obtained.
- Comparative Example B2 in which Cr was added beyond the scope of the present invention was not tested because the hot-rolled sheet was poor in toughness and cracks occurred in the next cold rolling process.
- ferritic stainless steel plate obtained by the present invention has excellent surface quality, it is suitable for use in automobile parts such as building materials and molding materials.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Heat Treatment Of Sheet Steel (AREA)
Abstract
Description
[1]質量%で、C:0.004%以上0.014%以下、N:0.004%以上0.014%以下、Si:0.01%以上0.30%以下、Mn:0.01%以上0.30%以下、P:0.025%以上0.040%以下、S:0.010%以下、Al:0.01%以上0.08%以下、Cr:10.5%以上24.0%以下、Ni:0.01%以上0.40%以下、Ti:0.20%以上0.38%以下、Nb:0.012%以下、O:0.0060%以下であり、かつ、(P%+S%+10×O%)×Ti%≦0.025を満足する範囲でP、S、O、Tiを含有し、残部がFeおよび不可避的不純物からなることを特徴とするフェライト系ステンレス鋼板。なお、前記P%、前記S%、前記O%、前記Ti%はそれぞれP、S、O、Tiの含有量(質量%)を表す。
[2]質量%で、さらに、Cu:0.01%以上0.48%以下、Mo:0.01%以上1.20%以下、V:0.01%以上0.10%以下のうちから選ばれる1種または2種以上を含有することを特徴とする前記[1]に記載のフェライト系ステンレス鋼板。
[3]質量%で、さらに、Zr:0.01%以上0.20%以下、REM:0.001%以上0.100%以下、W:0.01%以上0.20%以下、Co:0.01%以上0.20%以下、B:0.0002%以上0.0020%以下、Mg:0.0002%以上0.0010%以下、Ca:0.0005%以上0.0030%以下のうちから選ばれる1種または2種以上を含有することを特徴とする前記[1]または前記[2]に記載のフェライト系ステンレス鋼板。 The present invention has been made based on the above findings, and the gist thereof is as follows.
[1] By mass%, C: 0.004% to 0.014%, N: 0.004% to 0.014%, Si: 0.01% to 0.30%, Mn: 0.00. 01% to 0.30%, P: 0.025% to 0.040%, S: 0.010% or less, Al: 0.01% to 0.08%, Cr: 10.5% or more 24.0% or less, Ni: 0.01% or more and 0.40% or less, Ti: 0.20% or more and 0.38% or less, Nb: 0.012% or less, O: 0.0060% or less, And, it contains P, S, O, Ti in a range satisfying (P% + S% + 10 × O%) × Ti% ≦ 0.025, and the balance is made of Fe and inevitable impurities. Ferritic stainless steel sheet. The P%, the S%, the O%, and the Ti% represent the contents (mass%) of P, S, O, and Ti, respectively.
[2] By mass%, Cu: 0.01% to 0.48%, Mo: 0.01% to 1.20%, V: 0.01% to 0.10% The ferritic stainless steel sheet according to [1] above, which contains one or more selected.
[3] By mass%, Zr: 0.01% to 0.20%, REM: 0.001% to 0.100%, W: 0.01% to 0.20%, Co: 0.01% or more and 0.20% or less, B: 0.0002% or more and 0.0020% or less, Mg: 0.0002% or more and 0.0010% or less, Ca: 0.0005% or more and 0.0030% or less The ferritic stainless steel sheet according to [1] or [2] above, containing one or more selected from among them.
C量が0.014%を超えると加工性の低下および溶接を施した場合の溶接部の耐食性の低下が顕著になる。C量が低いほど耐食性および加工性の観点では好ましい。しかし、C量を0.004%未満にするためには精錬時間を長くする必要があり、製造上好ましくない。そのため、C量は0.004%以上0.014%以下の範囲とする。好ましくは0.004%以上0.011%以下の範囲である。より好ましくは0.005%以上0.008%以下の範囲である。 C: 0.004% or more and 0.014% or less When the amount of C exceeds 0.014%, the workability is deteriorated and the corrosion resistance of the welded part is significantly lowered when welding is performed. A lower C content is preferable from the viewpoint of corrosion resistance and workability. However, in order to make the amount of C less than 0.004%, it is necessary to lengthen the refining time, which is not preferable in production. For this reason, the C content is in the range of 0.004% to 0.014%. Preferably it is 0.004% or more and 0.011% or less of range. More preferably, it is 0.005% or more and 0.008% or less of range.
N量が0.014%を超えると加工性の低下および溶接を施した場合の溶接部の耐食性の低下が顕著になる。耐食性の観点からN量は低いほど好ましい。しかし、N量を0.004%未満にまで低減するには精錬時間を長くする必要があり、製造コストの上昇および生産性の低下を招くため好ましくない。よって、N量は0.004%以上0.014%以下の範囲とする。好ましくは0.004%以上0.011%以下の範囲である。より好ましくは0.006%以上0.009%以下の範囲である。 N: 0.004% or more and 0.014% or less When the N amount exceeds 0.014%, the workability is deteriorated and the corrosion resistance of the welded part is significantly lowered when welding is performed. From the viewpoint of corrosion resistance, the N content is preferably as low as possible. However, in order to reduce the amount of N to less than 0.004%, it is necessary to lengthen the refining time, which causes an increase in manufacturing cost and a decrease in productivity, which is not preferable. Therefore, the N amount is set in the range of 0.004% to 0.014%. Preferably it is 0.004% or more and 0.011% or less of range. More preferably, it is 0.006% or more and 0.009% or less of range.
Siは、製鋼工程における脱酸剤として有用な元素である。この効果はSi量を0.01%以上にすることで得られる。また、Si量が多いほどその効果は大きくなる。しかし、Si量が0.30%を超えると、熱間圧延工程における圧延荷重が増大して製造性が低下するとともに、表面に多量の酸化スケール(oxide scale)が生成し表面欠陥の増加が生じるため好ましくない。そのため、Si量は0.01%以上0.30%以下とする。焼鈍・酸洗工程において脱スケール(descaling)をより容易に行うためには、Si量を0.25%以下とすることが好ましい。より好ましくは0.20%以下である。 Si: 0.01% or more and 0.30% or less Si is an element useful as a deoxidizer in the steelmaking process. This effect can be obtained by making the Si amount 0.01% or more. The effect increases as the Si amount increases. However, if the amount of Si exceeds 0.30%, the rolling load in the hot rolling process increases and the productivity decreases, and a large amount of oxide scale is generated on the surface, resulting in an increase in surface defects. Therefore, it is not preferable. Therefore, the Si amount is set to 0.01% or more and 0.30% or less. In order to perform descaling more easily in the annealing / pickling process, the Si content is preferably 0.25% or less. More preferably, it is 0.20% or less.
Mnは、鋼板の強度を高める効果があり、また、脱酸剤としても有用な元素である。これらの効果を得るためには、Mn量を0.01%以上にすることが必要である。しかし、Mn量が0.30%を超えると、熱延板の焼鈍工程や冷延板の焼鈍工程で生成する酸化スケールの厚みが厚くなり、表面性状が低下する。そのため、Mn量は0.01%以上0.30%以下とする。好ましくは0.05%以上0.25%以下の範囲である。より好ましくは0.05%以上0.20%以下の範囲である。 Mn: 0.01% or more and 0.30% or less Mn has an effect of increasing the strength of the steel sheet, and is also an element useful as a deoxidizer. In order to acquire these effects, it is necessary to make Mn amount 0.01% or more. However, if the amount of Mn exceeds 0.30%, the thickness of the oxide scale generated in the annealing process of the hot-rolled sheet or the annealing process of the cold-rolled sheet becomes thick, and the surface properties are lowered. Therefore, the amount of Mn is 0.01% or more and 0.30% or less. Preferably it is 0.05 to 0.25% of range. More preferably, it is 0.05 to 0.20% of range.
Pは鋼板に不可避的に含まれる元素である。また、Pの過剰な含有は溶接性(weldability)を低下させ、粒界腐食(intergranular corrosion)を生じやすくさせる。この傾向はP量を0.040%超にすると顕著になる。P量が低いほど溶接性および粒界腐食の防止の観点では好ましい。しかし、P量を0.025%未満にするためには精錬時間を長くする必要があり、製造上好ましくない。そのため、P量は0.025%以上0.040%以下の範囲とする。好ましくは、0.025%以上0.035%以下である。より好ましくは、0.025%以上0.030%以下である。 P: 0.025% or more and 0.040% or less P is an element inevitably contained in the steel sheet. Further, excessive P content reduces weldability and easily causes intergranular corrosion. This tendency becomes remarkable when the amount of P exceeds 0.040%. A lower P content is preferable from the viewpoint of weldability and prevention of intergranular corrosion. However, in order to make the P amount less than 0.025%, it is necessary to lengthen the refining time, which is not preferable in production. Therefore, the P content is in the range of 0.025% to 0.040%. Preferably, it is 0.025% or more and 0.035% or less. More preferably, it is 0.025% or more and 0.030% or less.
SもPと同様に鋼板に不可避的に含まれる元素である。S量が0.010%超になると、耐食性が低下する。よって、S量は0.010%以下とする。好ましくは0.007%以下である。より好ましくは0.004%以下である。 S: 0.010% or less S, like P, is an element inevitably contained in the steel sheet. When the amount of S exceeds 0.010%, the corrosion resistance decreases. Therefore, the S amount is 0.010% or less. Preferably it is 0.007% or less. More preferably, it is 0.004% or less.
Alは有効な脱酸剤である。この脱酸剤としての効果はAl量を0.01%以上にすることで得られる。しかし、Al量が0.08%を超えると、Al系介在物(Al-based inclusion)による表面欠陥が生じる場合があるとともに、焼鈍工程における酸洗性が低下するため製造上好ましくない。そのため、Al量は0.01%以上0.08%以下の範囲とする。好ましくは0.01%以上0.06%以下の範囲である。より好ましくは0.02%以上0.05%以下の範囲である。 Al: 0.01% or more and 0.08% or less Al is an effective deoxidizer. This effect as a deoxidizer can be obtained by making the Al content 0.01% or more. However, if the amount of Al exceeds 0.08%, surface defects due to Al-based inclusions may occur, and pickling properties in the annealing process are deteriorated, which is not preferable in production. Therefore, the Al content is set in a range of 0.01% to 0.08%. Preferably it is 0.01% or more and 0.06% or less of range. More preferably, it is 0.02% or more and 0.05% or less.
Crはステンレス鋼板の耐食性を確保するために最も重要な元素である。Cr量が10.5%未満では十分な耐食性が得られない。一方、Cr量が24.0%を超えると、σ(シグマ)相(sigma phase)の生成により熱延板の靭性が低下し、熱延板の連続焼鈍が困難となるため製造上好ましくない。そのため、Cr量は10.5%以上24.0%以下の範囲とする。好ましくは12.0%以上24.0%以下の範囲である。より好ましくは15.0%以上21.5%以下の範囲である。さらにより好ましくは16.0%以上19.0%以下の範囲である。 Cr: 10.5% or more and 24.0% or less Cr is the most important element for securing the corrosion resistance of the stainless steel plate. If the Cr content is less than 10.5%, sufficient corrosion resistance cannot be obtained. On the other hand, if the Cr content exceeds 24.0%, the toughness of the hot-rolled sheet decreases due to the generation of a sigma phase, and continuous annealing of the hot-rolled sheet becomes difficult, which is not preferable in production. Therefore, the Cr content is in the range of 10.5% or more and 24.0% or less. Preferably it is 12.0% or more and 24.0% or less of range. More preferably, it is 15.0% or more and 21.5% or less of range. Even more preferably, it is in the range of 16.0% or more and 19.0% or less.
Niはステンレス鋼板の耐食性を向上させる元素であり、不動態皮膜(passivation film)が形成できず活性溶解(active dissolution)が生じる腐食環境において腐食の進行を抑制する元素である。この効果はNi量を0.01%以上にすることで得られ、Ni量が多いほど高くなる。しかし、Ni量が0.40%を超えると、加工性が低下することに加えて、応力腐食割れが発生しやすくなる。さらには、Niは高価な元素であるため、Ni量の増加は製造コストの増大を招くため好ましくない。そのため、Ni量は0.01%以上0.40%以下とする。好ましくは0.05%以上0.30%以下の範囲である。より好ましくは0.10%以上0.20%以下の範囲である。 Ni: 0.01% or more and 0.40% or less Ni is an element that improves the corrosion resistance of a stainless steel plate, and the progress of corrosion in a corrosive environment where a passive film cannot be formed and active dissolution occurs. It is an element which suppresses. This effect is obtained by setting the Ni content to 0.01% or more, and increases as the Ni content increases. However, when the Ni content exceeds 0.40%, workability is lowered and stress corrosion cracking is likely to occur. Furthermore, since Ni is an expensive element, an increase in the amount of Ni causes an increase in manufacturing cost, which is not preferable. Therefore, the Ni content is 0.01% or more and 0.40% or less. Preferably it is 0.05 to 0.30% of range. More preferably, it is 0.10% or more and 0.20% or less of range.
TiはCあるいはNと結合し、加工性を向上させたり溶接部の鋭敏化を防止して溶接部の耐食性を向上させたりする。この効果を得るためにはTi量を0.20%以上にする必要がある。しかし、Ti量が0.38%を超えると、鋳造工程において粗大なTi炭窒化物(Ti carbonitride)が生成し、表面欠陥を引き起こすため好ましくない。そのため、Ti量は0.20%以上0.38%以下とする。好ましくは0.20%以上0.35%以下の範囲である。より好ましくは0.25%以上0.35%以下の範囲である。 Ti: 0.20% or more and 0.38% or less Ti combines with C or N to improve workability or prevent the weld from becoming sensitized and improve the corrosion resistance of the weld. In order to obtain this effect, the Ti amount needs to be 0.20% or more. However, if the amount of Ti exceeds 0.38%, coarse Ti carbonitride is generated in the casting process and causes surface defects, which is not preferable. Therefore, the Ti amount is set to 0.20% or more and 0.38% or less. Preferably it is 0.20% or more and 0.35% or less of range. More preferably, it is 0.25% or more and 0.35% or less of range.
Nb量が0.012%を超えると再結晶温度(recrystallization temperature)が上昇し、熱延板の焼鈍温度や冷延板の焼鈍温度を上げなければ良好な機械的性質が得られなくなる。これらの焼鈍温度を上げると焼鈍時に生成するスケールが厚くなる。そのため、酸洗後に一部スケールが残ったり、厚いスケールを除去するために強い酸洗を行い表面が荒れたりし、表面性状が低下する。そのため、Nb量は0.012%以下とする。好ましくは0.008%以下である。より好ましくは0.005%以下である。 Nb: 0.012% or less If the Nb content exceeds 0.012%, the recrystallization temperature rises, and good mechanical properties are achieved unless the annealing temperature of the hot-rolled sheet or the annealing temperature of the cold-rolled sheet is increased. Cannot be obtained. When these annealing temperatures are raised, the scale generated during annealing becomes thicker. Therefore, some scales remain after pickling, or the surface is roughened by performing strong pickling to remove thick scales, and the surface properties are deteriorated. Therefore, the Nb content is 0.012% or less. Preferably it is 0.008% or less. More preferably, it is 0.005% or less.
Oは溶接時の溶け込み深さ(penetration depth)を向上させる元素である。しかし、O量が0.0060%を超えると、酸化物系の介在物(oxide inclusions)の量が増加し耐食性が低下する。そのため、O量は0.0060%以下とする。好ましくは0.0045%以下である。より好ましくは0.0030%以下である。 O: 0.0060% or less O is an element that improves the penetration depth during welding. However, if the amount of O exceeds 0.0060%, the amount of oxide inclusions increases and the corrosion resistance decreases. Therefore, the O amount is set to 0.0060% or less. Preferably it is 0.0045% or less. More preferably, it is 0.0030% or less.
TiはP、SおよびOと介在物を形成する。(P%+S%+10×O%)×Ti%が0.025を超えると、鋼板表面に生成するTi系介在物の量が増加するとともに介在物が粗大となり、表面欠陥や表面光沢の低下による表面品質が低下するので好ましくない。さらに、(P%+S%+10×O%)×Ti%が0.025を超えると、鋼板表面に生成した粗大なTi系介在物により不動態皮膜に欠陥ができて、耐食性が低下するので好ましくない。
そのため、(P%+S%+10×O%)×Ti%は0.025以下とする。なお、P%、S%、0%、Ti%はそれぞれP、S、O、Tiの含有量(質量%)を表す。 (P% + S% + 10 × O%) × Ti% ≦ 0.025
Ti forms inclusions with P, S and O. When (P% + S% + 10 × O%) × Ti% exceeds 0.025, the amount of Ti-based inclusions generated on the steel sheet surface increases and the inclusions become coarse, resulting in a decrease in surface defects and surface gloss. Since surface quality deteriorates, it is not preferable. Further, if (P% + S% + 10 × O%) × Ti% exceeds 0.025, it is preferable because coarse Ti-based inclusions generated on the surface of the steel sheet cause defects in the passive film and decrease the corrosion resistance. Absent.
Therefore, (P% + S% + 10 × O%) × Ti% is set to 0.025 or less. P%, S%, 0%, and Ti% represent the contents (mass%) of P, S, O, and Ti, respectively.
Cu:0.01%以上0.48%以下
Cuは耐食性を向上させる元素である。また、Cuは、鋼板が水溶液中にある場合や弱酸性の水滴が鋼板に付着した場合の母材および溶接部の耐食性を向上させるのに特に有効な元素である。この効果はCuを0.01%以上にすることで得られ、その効果はCu量が大きいほど高くなる。しかし、Cu量が0.48%を超えると、熱間加工性が低下するとともに、熱間圧延時に赤スケール(red scale)と呼ばれるCu起因の酸化物がスラブ上に生成し、表面欠陥が生じるため好ましくない。さらには焼鈍後の脱スケールが困難となるため製造上好ましくない。そのため、Cuを添加する場合、Cu量は0.01%以上0.48%以下の範囲とする。好ましくは、0.10%以上0.48%以下の範囲である。より好ましくは0.30%以上0.45%以下の範囲である。 One or more of Cu, Mo, and V Cu: 0.01% or more and 0.48% or less Cu is an element that improves corrosion resistance. Cu is an element particularly effective for improving the corrosion resistance of the base material and the weld when the steel plate is in an aqueous solution or when weakly acidic water droplets adhere to the steel plate. This effect is obtained by making Cu 0.01% or more, and the effect becomes higher as the amount of Cu increases. However, when the amount of Cu exceeds 0.48%, hot workability is deteriorated, and an oxide derived from Cu called red scale is formed on the slab during hot rolling, resulting in surface defects. Therefore, it is not preferable. Furthermore, since descaling after annealing becomes difficult, it is not preferable in production. Therefore, when adding Cu, the amount of Cu shall be 0.01% or more and 0.48% or less. Preferably, it is 0.10% or more and 0.48% or less of range. More preferably, it is 0.30% or more and 0.45% or less of range.
Moはステンレス鋼板の耐食性を顕著に向上させる元素である。この効果はMo量を0.01%以上にすることで得られ、Mo量が多いほど向上する。しかし、Mo量が1.20%を超えると、熱間加工性が低下して熱間圧延時に表面欠陥が多発するようになる。また、Moは高価な元素であることから、多量の添加は製造コストを増大させる。そのため、Moを添加する場合、Mo量は0.01%以上1.20%以下とする。好ましくは0.30%以上1.20%以下の範囲である。より好ましくは0.30%以上0.90%以下の範囲である。さらに好ましくは0.40%以上0.60%以下の範囲である。 Mo: 0.01% or more and 1.20% or less Mo is an element that remarkably improves the corrosion resistance of the stainless steel plate. This effect is obtained by setting the Mo amount to 0.01% or more, and the effect increases as the Mo amount increases. However, if the Mo content exceeds 1.20%, the hot workability is deteriorated and surface defects frequently occur during hot rolling. Moreover, since Mo is an expensive element, the addition of a large amount increases the manufacturing cost. Therefore, when adding Mo, the amount of Mo shall be 0.01% or more and 1.20% or less. Preferably it is 0.30% or more and 1.20% or less of range. More preferably, it is 0.30% or more and 0.90% or less of range. More preferably, it is 0.40% or more and 0.60% or less of range.
Vは焼鈍後の結晶粒を微細化し、表面の肌荒れ(surface deteorations)の防止や疲労特性の向上に有効な元素である。また、VはCあるいはNと結合して溶接部の鋭敏化による耐食性の低下を抑制する効果がある。これらの効果はV量を0.01%以上にすることで得られる。しかし、V量が0.10%を超えると加工性が低下するとともに、原料コストが上昇するため好ましくない。そのため、Vを添加する場合、V量は0.01%以上0.10%以下の範囲とする。好ましくは0.01%以上0.07%以下の範囲である。より好ましくは0.02%以上0.05%以下の範囲である。 V: 0.01% or more and 0.10% or less V is an element effective for refining crystal grains after annealing, preventing surface deteorations and improving fatigue characteristics. Further, V is combined with C or N and has an effect of suppressing a decrease in corrosion resistance due to the sensitization of the welded portion. These effects can be obtained by making the V amount 0.01% or more. However, if the V amount exceeds 0.10%, the workability is lowered and the raw material cost is increased, which is not preferable. Therefore, when adding V, the amount of V is made 0.01% or more and 0.10% or less. Preferably it is 0.01% or more and 0.07% or less of range. More preferably, it is 0.02% or more and 0.05% or less.
Zr:0.01%以上0.20%以下
ZrはC、Nと結合して溶接部の鋭敏化を抑制する効果があるとともに高温強度を上昇させる効果がある。これらの効果はZr量を0.01%以上にすることで得られる。一方、Zr量が0.20%を超えると加工性が低下する。また、Zrは高価な元素であるため、過度な添加は製造コストの増加を招くため好ましくない。そのため、Zrを添加する場合、Zr量は0.01%以上0.20%以下の範囲とする。好ましくは、0.01%以上0.10%以下の範囲とする。 One or more selected from Zr, REM, W, Co, B, Mg, Ca Zr: 0.01% or more and 0.20% or less Zr combines with C and N to sensitize welds Has the effect of increasing the high temperature strength. These effects can be obtained by making the amount of Zr 0.01% or more. On the other hand, if the amount of Zr exceeds 0.20%, workability deteriorates. Moreover, since Zr is an expensive element, excessive addition causes an increase in manufacturing cost, which is not preferable. Therefore, when adding Zr, the amount of Zr shall be 0.01% or more and 0.20% or less. Preferably, the range is 0.01% or more and 0.10% or less.
REMは耐酸化性(oxidation resistance)を向上させる効果があり、特に溶接部の酸化皮膜(oxide film)の形成を抑制し溶接部の耐食性を向上させる効果がある。この効果を得るためにはREM量を0.001%以上にする必要がある。一方、REM量が0.100%を超えると熱間圧延性が低下して表面欠陥が多発するので好ましくない。そのため、REMを添加する場合、REM量は0.001%以上0.100%以下の範囲とする。好ましくは、0.001%以上0.050%以下の範囲とする。 REM: 0.001% or more and 0.100% or less REM has the effect of improving oxidation resistance, and in particular, suppresses the formation of an oxide film on the weld and improves the corrosion resistance of the weld. effective. In order to obtain this effect, the REM amount needs to be 0.001% or more. On the other hand, if the amount of REM exceeds 0.100%, the hot rollability deteriorates and surface defects frequently occur, which is not preferable. Therefore, when adding REM, the amount of REM shall be 0.001% or more and 0.100% or less. Preferably, it is set as 0.001% or more and 0.050% or less of range.
WはMoと同様に耐食性を向上させる効果がある。この効果はW量を0.01%以上にすることで得られる。一方、W量が0.20%を超えると強度が上昇し、圧延荷重の増大等による製造性の低下を招くため好ましくない。そのため、Wを添加する場合、W量は0.01%以上0.20%以下の範囲とする。好ましくは、0.01%以上0.10%以下の範囲とする。 W: 0.01% or more and 0.20% or less W, like Mo, has the effect of improving the corrosion resistance. This effect can be obtained by making the W amount 0.01% or more. On the other hand, if the amount of W exceeds 0.20%, the strength increases, and the productivity is lowered due to an increase in rolling load or the like, which is not preferable. For this reason, when W is added, the W content is in the range of 0.01% to 0.20%. Preferably, the range is 0.01% or more and 0.10% or less.
Coは靭性を向上させる元素である。この効果はCo量を0.01%以上にすることで得られる。一方、Co量が0.20%を超えると加工性が低下する。そのため、Coを添加する場合、Co量は0.01%以上0.20%以下の範囲とする。好ましくは、0.01%以上0.10%以下の範囲とする。 Co: 0.01% or more and 0.20% or less Co is an element that improves toughness. This effect can be obtained by making the Co content 0.01% or more. On the other hand, if the amount of Co exceeds 0.20%, workability deteriorates. Therefore, when adding Co, the amount of Co is set to a range of 0.01% or more and 0.20% or less. Preferably, the range is 0.01% or more and 0.10% or less.
Bは深絞り成形(deep drawing)後の耐二次加工脆性(resistance to secondary working embrittlement)を改善するために有効な元素である。この効果はB量を0.0002%以上にすることで得られる。一方、B量が0.0020%を超えると熱間圧延時の圧延荷重が増大し表面欠陥が増大するので好ましくない。そのため、Bを添加する場合、B量は0.0002%以上0.0020%以下の範囲とする。好ましくは0.0005%以上0.0015%以下の範囲である。 B: 0.0002% or more and 0.0020% or less B is an element effective for improving resistance to secondary working embrittlement after deep drawing. This effect can be obtained by making the B amount 0.0002% or more. On the other hand, if the amount of B exceeds 0.0020%, the rolling load during hot rolling increases and surface defects increase, which is not preferable. Therefore, when adding B, the amount of B is made into the range of 0.0002% or more and 0.0020% or less. Preferably it is 0.0005% or more and 0.0015% or less of range.
Mgはスラブの等軸晶率(rate of equiaxed crystals)を向上させ、加工性や靭性の向上に有効な元素である。さらに、本発明のようにTiを含む鋼板においては、Ti炭窒化物が粗大化すると靭性が低下するが、MgはTi炭窒化物の粗大化を抑制する効果も有する。これらの効果はMg量を0.0002%以上にすることで得られる。一方で、Mg量が0.0010%を超えると、Mg介在物量が増えて鋼板の表面性状を悪化させてしまう。したがって、Mgを添加する場合、Mg量は0.0002%以上0.0010%以下の範囲とする。好ましくは0.0002%以上0.0004%以下の範囲である。 Mg: 0.0002% or more and 0.0010% or less Mg is an element that improves the rate of equiaxed crystals of the slab and is effective in improving workability and toughness. Furthermore, in a steel sheet containing Ti as in the present invention, the toughness decreases when the Ti carbonitride becomes coarse, but Mg also has an effect of suppressing the coarsening of the Ti carbonitride. These effects can be obtained by setting the Mg amount to 0.0002% or more. On the other hand, if the amount of Mg exceeds 0.0010%, the amount of Mg inclusions increases and the surface properties of the steel sheet are deteriorated. Therefore, when adding Mg, the amount of Mg is set in the range of 0.0002% to 0.0010%. Preferably it is 0.0002% or more and 0.0004% or less of range.
Caは、連続鋳造の際に発生しやすいTi系介在物の析出によるノズルの閉塞(choke of nozzle)を防止するのに有効な成分である。その効果はCa量を0.0005%以上にすることで得られる。しかし、Ca量が0.0030%を超えるとCaSの生成により耐食性が低下する。従って、Caを添加する場合、Ca量は0.0005%以上0.0030%以下の範囲とする。好ましくは0.0005%以上0.0020%以下の範囲である。より好ましくは0.0005%以上0.0015%以下の範囲である。 Ca: 0.0005% or more and 0.0030% or less Ca is an effective component for preventing the choke of nozzle due to precipitation of Ti inclusions which are likely to occur during continuous casting. The effect is acquired by making Ca amount 0.0005% or more. However, if the Ca content exceeds 0.0030%, the corrosion resistance decreases due to the formation of CaS. Therefore, when Ca is added, the Ca content is in the range of 0.0005% to 0.0030%. Preferably it is 0.0005% or more and 0.0020% or less of range. More preferably, it is 0.0005% or more and 0.0015% or less of range.
Claims (3)
- 質量%で、C:0.004%以上0.014%以下、N:0.004%以上0.014%以下、Si:0.01%以上0.30%以下、Mn:0.01%以上0.30%以下、P:0.025%以上0.040%以下、S:0.010%以下、Al:0.01%以上0.08%以下、Cr:10.5%以上24.0%以下、Ni:0.01%以上0.40%以下、Ti:0.20%以上0.38%以下、Nb:0.012%以下、O:0.0060%以下であり、かつ、
(P%+S%+10×O%)×Ti%≦0.025を満足する範囲でP、S、O、Tiを含有し、残部がFeおよび不可避的不純物からなることを特徴とするフェライト系ステンレス鋼板。なお、前記P%、前記S%、前記0%、前記Ti%はそれぞれP、S、O、Tiの含有量(質量%)を表す。 C: 0.004% to 0.014%, N: 0.004% to 0.014%, Si: 0.01% to 0.30%, Mn: 0.01% or more 0.30% or less, P: 0.025% or more and 0.040% or less, S: 0.010% or less, Al: 0.01% or more and 0.08% or less, Cr: 10.5% or more and 24.0 %: Ni: 0.01% or more and 0.40% or less, Ti: 0.20% or more and 0.38% or less, Nb: 0.012% or less, O: 0.0060% or less, and
(P% + S% + 10 × O%) × Ti% ≦ 0.025 is contained, P, S, O, Ti is contained, and the balance consists of Fe and unavoidable impurities. steel sheet. The P%, the S%, the 0%, and the Ti% represent the contents (mass%) of P, S, O, and Ti, respectively. - 質量%で、さらに、Cu:0.01%以上0.48%以下、Mo:0.01%以上1.20%以下、V:0.01%以上0.10%以下のうちから選ばれる1種または2種以上を含有することを特徴とする請求項1に記載のフェライト系ステンレス鋼板。 1% selected from Cu: 0.01% to 0.48%, Mo: 0.01% to 1.20%, and V: 0.01% to 0.10%. The ferritic stainless steel sheet according to claim 1, comprising seeds or two or more kinds.
- 質量%で、さらに、Zr:0.01%以上0.20%以下、REM:0.001%以上0.100%以下、W:0.01%以上0.20%以下、Co:0.01%以上0.20%以下、B:0.0002%以上0.0020%以下、Mg:0.0002%以上0.0010%以下、Ca:0.0005%以上0.0030%以下のうちから選ばれる1種または2種以上を含有することを特徴とする請求項1または請求項2に記載のフェライト系ステンレス鋼板。 Further, Zr: 0.01% to 0.20%, REM: 0.001% to 0.100%, W: 0.01% to 0.20%, Co: 0.01 %: 0.202% or less, B: 0.0002% or more and 0.0020% or less, Mg: 0.0002% or more and 0.0010% or less, Ca: 0.0005% or more and 0.0030% or less The ferritic stainless steel sheet according to claim 1, wherein the ferritic stainless steel sheet contains at least one kind selected from the above.
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
IN1886DEN2015 IN2015DN01886A (en) | 2012-12-07 | 2013-12-04 | |
KR1020157006722A KR101705135B1 (en) | 2012-12-07 | 2013-12-04 | Ferritic stainless steel sheet |
MYPI2015701001A MY182247A (en) | 2012-12-07 | 2013-12-04 | Ferritic stainless steel sheet |
JP2014519731A JP5664826B2 (en) | 2012-12-07 | 2013-12-04 | Ferritic stainless steel sheet |
CN201380051013.5A CN104685089B (en) | 2012-12-07 | 2013-12-04 | Ferrite series stainless steel plate |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2012267907 | 2012-12-07 | ||
JP2012-267907 | 2012-12-07 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2014087648A1 true WO2014087648A1 (en) | 2014-06-12 |
Family
ID=50883088
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2013/007124 WO2014087648A1 (en) | 2012-12-07 | 2013-12-04 | Ferritic stainless steel sheet |
Country Status (7)
Country | Link |
---|---|
JP (1) | JP5664826B2 (en) |
KR (1) | KR101705135B1 (en) |
CN (1) | CN104685089B (en) |
IN (1) | IN2015DN01886A (en) |
MY (1) | MY182247A (en) |
TW (1) | TWI546389B (en) |
WO (1) | WO2014087648A1 (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP3438310A4 (en) * | 2016-03-29 | 2019-02-06 | JFE Steel Corporation | Ferritic stainless steel sheet |
JP2020164924A (en) * | 2019-03-29 | 2020-10-08 | 日鉄ステンレス株式会社 | High-purity ferritic stainless steel and high-purity ferritic stainless steel cast slab |
US11261512B2 (en) | 2016-09-02 | 2022-03-01 | Jfe Steel Corporation | Ferritic stainless steel |
US11326236B2 (en) * | 2017-02-23 | 2022-05-10 | Nippon Steel Stainless Steel Corporation | Black ferrite-based stainless steel sheet |
US11365467B2 (en) | 2017-05-26 | 2022-06-21 | Jfe Steel Corporation | Ferritic stainless steel |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN106256919B (en) * | 2015-06-17 | 2020-07-14 | 宝钢德盛不锈钢有限公司 | Low-cost ferritic stainless steel with condensate corrosion resistance and manufacturing method thereof |
JP5884211B1 (en) * | 2015-07-02 | 2016-03-15 | Jfeスチール株式会社 | Ferritic stainless steel sheet and manufacturing method thereof |
EP3318654B1 (en) * | 2015-09-30 | 2019-05-01 | JFE Steel Corporation | Ferrite stainless steel sheet |
CN108411198A (en) * | 2018-03-28 | 2018-08-17 | 浙江益宏不锈钢有限公司 | A kind of high-performance stainless steel and seamless steel pipe and its manufacturing method |
JP7395737B2 (en) * | 2020-06-02 | 2023-12-11 | 日鉄ステンレス株式会社 | Ferritic stainless steel |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH07268485A (en) * | 1994-03-30 | 1995-10-17 | Kawasaki Steel Corp | Production of ferritic stainless steel strip excellent in workability, corrosion resistance, and surface characteristic |
JPH1060543A (en) * | 1996-08-15 | 1998-03-03 | Nippon Steel Corp | Production of ferritic stainless steel thin sheet excellent in surface property and corrosion resistance |
JP2000144342A (en) * | 1998-01-30 | 2000-05-26 | Sumitomo Metal Ind Ltd | Ferritic stainless steel and ferritic stainless steel slab excellent in formability |
JP2004169150A (en) * | 2002-11-21 | 2004-06-17 | Jfe Steel Kk | Ti-CONTAINING HIGH WORKABILITY FERRITIC CHROMIUM STEEL SHEET HAVING EXCELLENT RIDGING RESISTANCE, AND PRODUCTION METHOD THEREFOR |
JP2007262474A (en) * | 2006-03-28 | 2007-10-11 | Jfe Steel Kk | Ferritic stainless steel sheet having excellent rust removability and rusting resistance |
JP2008261007A (en) * | 2007-04-12 | 2008-10-30 | Jfe Steel Kk | Ferritic stainless steel having excellent corrosion resistance in the existence of chlorine-based bleaching agent |
JP2008274328A (en) * | 2007-04-26 | 2008-11-13 | Jfe Steel Kk | Ferritic stainless steel sheet excellent in stretch-flanging formability and producing method therefor |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4390962B2 (en) * | 2000-04-04 | 2009-12-24 | 新日鐵住金ステンレス株式会社 | High purity ferritic stainless steel with excellent surface properties and corrosion resistance |
JP2002275590A (en) | 2001-03-14 | 2002-09-25 | Nisshin Steel Co Ltd | Ferritic stainless steel for welding having excellent workability in weld zone |
JP5793283B2 (en) * | 2010-08-06 | 2015-10-14 | 新日鐵住金ステンレス株式会社 | Ferritic stainless steel with few black spots |
-
2013
- 2013-12-04 CN CN201380051013.5A patent/CN104685089B/en active Active
- 2013-12-04 MY MYPI2015701001A patent/MY182247A/en unknown
- 2013-12-04 JP JP2014519731A patent/JP5664826B2/en active Active
- 2013-12-04 IN IN1886DEN2015 patent/IN2015DN01886A/en unknown
- 2013-12-04 WO PCT/JP2013/007124 patent/WO2014087648A1/en active Application Filing
- 2013-12-04 KR KR1020157006722A patent/KR101705135B1/en active IP Right Grant
- 2013-12-06 TW TW102144786A patent/TWI546389B/en active
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH07268485A (en) * | 1994-03-30 | 1995-10-17 | Kawasaki Steel Corp | Production of ferritic stainless steel strip excellent in workability, corrosion resistance, and surface characteristic |
JPH1060543A (en) * | 1996-08-15 | 1998-03-03 | Nippon Steel Corp | Production of ferritic stainless steel thin sheet excellent in surface property and corrosion resistance |
JP2000144342A (en) * | 1998-01-30 | 2000-05-26 | Sumitomo Metal Ind Ltd | Ferritic stainless steel and ferritic stainless steel slab excellent in formability |
JP2004169150A (en) * | 2002-11-21 | 2004-06-17 | Jfe Steel Kk | Ti-CONTAINING HIGH WORKABILITY FERRITIC CHROMIUM STEEL SHEET HAVING EXCELLENT RIDGING RESISTANCE, AND PRODUCTION METHOD THEREFOR |
JP2007262474A (en) * | 2006-03-28 | 2007-10-11 | Jfe Steel Kk | Ferritic stainless steel sheet having excellent rust removability and rusting resistance |
JP2008261007A (en) * | 2007-04-12 | 2008-10-30 | Jfe Steel Kk | Ferritic stainless steel having excellent corrosion resistance in the existence of chlorine-based bleaching agent |
JP2008274328A (en) * | 2007-04-26 | 2008-11-13 | Jfe Steel Kk | Ferritic stainless steel sheet excellent in stretch-flanging formability and producing method therefor |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP3438310A4 (en) * | 2016-03-29 | 2019-02-06 | JFE Steel Corporation | Ferritic stainless steel sheet |
US20190106775A1 (en) * | 2016-03-29 | 2019-04-11 | Jfe Steel Corporation | Ferritic stainless steel sheet |
US11261512B2 (en) | 2016-09-02 | 2022-03-01 | Jfe Steel Corporation | Ferritic stainless steel |
US11326236B2 (en) * | 2017-02-23 | 2022-05-10 | Nippon Steel Stainless Steel Corporation | Black ferrite-based stainless steel sheet |
US11365467B2 (en) | 2017-05-26 | 2022-06-21 | Jfe Steel Corporation | Ferritic stainless steel |
JP2020164924A (en) * | 2019-03-29 | 2020-10-08 | 日鉄ステンレス株式会社 | High-purity ferritic stainless steel and high-purity ferritic stainless steel cast slab |
JP7271261B2 (en) | 2019-03-29 | 2023-05-11 | 日鉄ステンレス株式会社 | High-purity ferritic stainless steel and high-purity ferritic stainless steel slab |
Also Published As
Publication number | Publication date |
---|---|
TW201435096A (en) | 2014-09-16 |
JPWO2014087648A1 (en) | 2017-01-05 |
KR20150038680A (en) | 2015-04-08 |
MY182247A (en) | 2021-01-18 |
CN104685089A (en) | 2015-06-03 |
TWI546389B (en) | 2016-08-21 |
JP5664826B2 (en) | 2015-02-04 |
IN2015DN01886A (en) | 2015-08-07 |
CN104685089B (en) | 2016-08-17 |
KR101705135B1 (en) | 2017-02-09 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5664826B2 (en) | Ferritic stainless steel sheet | |
TWI377257B (en) | Excellent heat-resistance ferrite stainless steel | |
JP5987996B2 (en) | Ferritic stainless steel and manufacturing method thereof | |
TWI460291B (en) | Ferritic stainless steel | |
TWI516614B (en) | Fat iron stainless steel | |
CN107709592B (en) | Ferrite series stainless steel plate and its manufacturing method | |
JP5904310B1 (en) | Ferritic stainless steel and manufacturing method thereof | |
EP3587610B1 (en) | Hot-rolled and annealed ferritic stainless steel sheet, and method for manufacturing same | |
KR20190032477A (en) | Ferritic stainless steel hot-rolled annealed steel sheet and manufacturing method thereof | |
JP5862846B2 (en) | Ferritic stainless steel and manufacturing method thereof | |
JP6411881B2 (en) | Ferritic stainless steel and manufacturing method thereof | |
CN111295458A (en) | Ferritic stainless steel sheet and method for producing same | |
JP5556951B2 (en) | Ferritic stainless steel | |
WO2015015735A1 (en) | Ferritic stainless steel having excellent weld corrosion resistance | |
US20170275722A1 (en) | Ferritic stainless steel sheet | |
JP7038799B2 (en) | Ferritic stainless hot-rolled annealed steel sheet and its manufacturing method | |
JP7465955B2 (en) | Low Cr ferritic stainless steel sheet with improved pipe expansion workability and its manufacturing method |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
ENP | Entry into the national phase |
Ref document number: 2014519731 Country of ref document: JP Kind code of ref document: A |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 13861452 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 20157006722 Country of ref document: KR Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: IDP00201501861 Country of ref document: ID |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 13861452 Country of ref document: EP Kind code of ref document: A1 |