WO2009139355A1 - フェライト系ステンレス鋼 - Google Patents
フェライト系ステンレス鋼 Download PDFInfo
- Publication number
- WO2009139355A1 WO2009139355A1 PCT/JP2009/058778 JP2009058778W WO2009139355A1 WO 2009139355 A1 WO2009139355 A1 WO 2009139355A1 JP 2009058778 W JP2009058778 W JP 2009058778W WO 2009139355 A1 WO2009139355 A1 WO 2009139355A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- less
- stainless steel
- brazing
- ferritic stainless
- content
- Prior art date
Links
Images
Classifications
-
- 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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
- B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
- B23K35/24—Selection of soldering or welding materials proper
- B23K35/30—Selection of soldering or welding materials proper with the principal constituent melting at less than 1550 degrees C
- B23K35/302—Cu as the principal constituent
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
- B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
- B23K35/24—Selection of soldering or welding materials proper
- B23K35/30—Selection of soldering or welding materials proper with the principal constituent melting at less than 1550 degrees C
- B23K35/3033—Ni as the principal constituent
-
- 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
- C21D8/0273—Final recrystallisation annealing
-
- 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
- C22C38/26—Ferrous alloys, e.g. steel alloys containing chromium with niobium or tantalum
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28F21/00—Constructions of heat-exchange apparatus characterised by the selection of particular materials
- F28F21/08—Constructions of heat-exchange apparatus characterised by the selection of particular materials of metal
- F28F21/081—Heat exchange elements made from metals or metal alloys
- F28F21/082—Heat exchange elements made from metals or metal alloys from steel or ferrous alloys
- F28F21/083—Heat exchange elements made from metals or metal alloys from steel or ferrous alloys from stainless steel
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K2103/00—Materials to be soldered, welded or cut
- B23K2103/02—Iron or ferrous alloys
- B23K2103/04—Steel or steel alloys
- B23K2103/05—Stainless steel
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/12—All metal or with adjacent metals
- Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
- Y10T428/12771—Transition metal-base component
- Y10T428/12861—Group VIII or IB metal-base component
- Y10T428/12951—Fe-base component
- Y10T428/12972—Containing 0.01-1.7% carbon [i.e., steel]
- Y10T428/12979—Containing more than 10% nonferrous elements [e.g., high alloy, stainless]
Definitions
- the present invention relates to a ferritic stainless steel suitable for use in a member to be brazed. Furthermore, the present invention relates to a ferritic stainless steel particularly suitable for use as a member constituting a heat exchanger.
- Heat exchangers are used in various fields such as gas water heaters and eco-cute can heat exchange plates for the purpose of effectively reusing exhausted gas.
- a gas water heater components of exhaust heat gas condense and a mixture of nitric acid, sulfuric acid, and chlorine is generated, and the heat exchanger plate is concerned about corrosion resistance due to high chlorine concentration in the liquid due to heat exchange of liquid / liquid. It is a part to be done.
- Ni brazing or Cu brazing is used for joining parts, and it is necessary to avoid ductility and toughness due to coarsening of the structure during brazing.
- copper and copper alloys have been used for members that require such corrosion resistance and brazing.
- austenitic stainless steels such as SUS304 and SUS316 have been used for heat exchanger steel members as an alternative to copper.
- brazing member The following characteristics are required for a member to be brazed.
- Various brazing properties such as Ni brazing property, Cu brazing property, and torch brazing property using inexpensive brass brazing are good.
- the brazing member is a metal member such as a heat exchanger member (refrigerant pipe or water pipe)
- the following characteristics are also required.
- Condensation water discharged from combustion gas has good corrosion resistance in nitric acid or sulfuric acid environment, and crevice corrosion resistance in water environment with high chlorine concentration.
- ferritic stainless steel is examined in Japanese Patent No. 2642056.
- Ferritic stainless steel has a thermal expansion coefficient smaller than that of austenitic steel, and the material cost is generally lower than that of austenitic steel.
- Ferritic stainless steel is often used for exhaust heat recovery members and muffler members in the exhaust gas path of automobiles.
- brazing such as Ni brazing, Cu brazing or torch brazing
- it is necessary to expose the material to a high temperature of 1000 ° C. or higher.
- ferritic stainless steel is usually austenite.
- diffusion is likely to occur, and the ductility and toughness are liable to decrease due to coarsening of crystal grains.
- Japanese Patent No. 2642056 discloses ferritic stainless steel for heat exchangers with good brazing properties. However, it is not intended for grain coarsening during brazing or crevice corrosion in an aqueous environment.
- the present invention is intended to provide a ferritic stainless steel suitable as a member used for brazing such as torch brazing using Ni brazing, Cu brazing, brass brazing or the like. Furthermore, the present invention provides a ferritic stainless steel suitable as a material for metal members such as heat exchanger members, which has not only brazing properties but also corrosion resistance in an environment where high chlorine concentration water exists. Objective.
- the purpose is mass%, C: 0.03% or less, Si: 3% or less, Mn: 2% or less, P: 0.05% or less, S: 0.03% or less, Cr: 17 to 26% Nb: 0.15 to 0.8%, N: 0.03% or less, and the balance is mainly composed of Fe and inevitable impurities,
- a value representing the amount of solute Nb is 0.10 or more
- A Nb ⁇ (C ⁇ 92.9 / 12 + N ⁇ 92.9 / 14) It is characterized by This is achieved by applying ferritic stainless steel. Further, it is preferable that the maximum diameter d of the precipitate in the ferritic stainless steel is 0.25 ⁇ m or less and the volume fraction f of the precipitate is 0.05% or more.
- a ferritic stainless steel having good Ni brazing and Cu brazing properties, corrosion resistance in gas condensed water, crevice corrosion resistance in a water environment, and good ductility and toughness.
- a heat exchanger having a lower material cost than that of a conventional heat exchanger member using austenitic stainless steel as a member is realized.
- ferritic stainless steel is advantageous for reducing the cost of various members such as heat exchanger members.
- ferritic stainless steel when ferritic stainless steel is used, there are concerns about corrosion resistance in a gas condensed water environment and crevice corrosion resistance in an aqueous environment.
- there is a component design for suppressing coarsening of crystal grains. is important. That is, when ferritic stainless steel is held at such a high temperature, crystal grains tend to grow and become coarse. When the crystal grains in the stainless steel are coarsened, the fatigue characteristics are deteriorated, and are easily damaged by vibrations or external impacts.
- solute Nb works effectively in the corrosion resistance of ferritic stainless steel in a gas condensate environment and crevice corrosion resistance in an aqueous environment.
- Nb revealed that the passive film has a high repair ability.
- solute Nb acts effectively in suppressing the grain coarsening of ferritic stainless steel.
- the amount of Nb required to suppress the coarsening of crystal grains in the ferritic stainless steel is ensured to be at least 0.15 Nb. It became clear that more than% is necessary.
- the crystal grain coarsening suppression by solid solution Nb is based on the drag effect mentioned later, it is not restricted to this.
- the suppression of crystal grain coarsening by addition of Nb has a large pinning effect of suppressing grain growth by Nb carbonitride in addition to the grain coarsening suppression action by the drag effect that suppresses the diffusion of other elements by solid solution Nb. Presumed to be working. Therefore, it is more advantageous to secure the C and N contents to some extent in the component design in the present invention. Specifically, it is more effective to set the total content of C and N to 0.01% or more. Moreover, it is considered that by securing a sufficient Nb content, the pinning effect due to precipitates such as Fe 2 Nb (Laves phase) and Fe 3 NbC is also effective in suppressing the grain coarsening. By suppressing the coarsening of the crystal grains during brazing, it is effective in preventing toughness and ductility deterioration.
- Nb is an element that easily binds to C and N, it is the remaining Nb used for Nb carbonitride generation that can become solute Nb among Nb in stainless steel. Therefore, the amount of Nb that can be dissolved in stainless steel can be expressed using the A value as shown in the following formula.
- A Nb ⁇ (C ⁇ 92.9 / 12 + N ⁇ 92.9 / 14)
- C and N represent the contents (mass%) of C and N in stainless steel, respectively.
- a value or A 'value when the ferritic stainless steel contains more Ti than the total content of C and N. Is effectively expressed when the amount of Nb that can be dissolved is 0.10 or more, and grain boundary migration is suppressed. As a result, the grain size of ferritic stainless steel is increased at high temperatures (such as during brazing). It was found that can be suppressed.
- the A value and the A ′ value are preferably 0.2 or more, and more preferably 0.25 or more.
- the inventors evaluated the coarsening of the crystal grains when the precipitate volume fraction f was 0.05 to 0.20% and the diameter d ( ⁇ m) of the precipitates was changed, and the d / f was 5 It was discovered that the crystal grain size of stainless steel was 500 ⁇ m or more by brazing treatment. Therefore, in the present invention, it is preferable to control the amount and diameter of the precipitate so that d / f is 5 or less. In other words, the pinning effect increases as the particle size of the individual precipitates decreases and the total volume ratio of the precipitates increases. In order to finely disperse the precipitates, it is important to suppress the coarsening of the precipitates during heating and cooling during the production of stainless steel.
- the coiling temperature is less than 750 ° C.
- the average heating rate from 600 ° C. to the highest material temperature Tm is 10 ° C./s or more
- the average cooling rate from Tm to 600 ° C. is 10 ° C. It was found that a precipitate having a maximum diameter of 0.25 ⁇ m or less can be obtained by controlling to / s or more. In this case, if the volume ratio f is 0.05 or more, the pinning effect required in the present invention can be obtained. Therefore, in the present invention, it is preferable to control so that the maximum diameter d of the precipitate is 0.25 ⁇ m or less and the volume fraction f of the precipitate is 0.05% or more.
- the maximum diameter d ( ⁇ m) of the precipitate means the maximum value of the particle diameter of the precipitate appearing in the cross section when the steel material cross section is polished, and the particle diameter is the smallest area circumscribing the particle.
- the volume fraction f (%) of the precipitate means a value converted into a percentage by dividing the total area of all the precipitates appearing in the cross section when the steel material cross section is polished by the area of the observation field.
- the cross section can be observed with a scanning electron microscope (SEM) or the like, and the area of the observation field is 2 ⁇ 10 ⁇ 2 mm 2 or more.
- Nb-based precipitates such as Nb carbide, Nb nitride, and Nb carbonitride (hereinafter collectively referred to as “Nb-based carbon / nitride”).
- Nb-based carbon / nitride Nb carbonitride
- Fe 2 Nb Long phase
- Fe 3 NbC Fe 3 NbC
- alloy components other than Nb it was found that Mo and W have a drag effect due to a drag effect and Ti has a pinning effect due to precipitation of TiC or the like. Further, it has been found that Ni, Co, and Cu are extremely effective for suppressing a decrease in toughness when ferrite grains are coarsened during brazing. On the other hand, it has been clarified that Ti, Al, Zr, REM, and Ca have a factor that deteriorates the flow of the brazing material on the steel surface when performing Ni brazing or Cu brazing. This is considered to be due to the fact that oxides of these elements are easily formed on the steel surface during brazing heating. However, there will be no problem if the content of these elements is regulated within an appropriate range as will be described later.
- the C content needs to be limited to 0.03% by mass or less, and is preferably 0.025% by mass or less.
- the N content must be limited to 0.03% by mass or less, and is preferably 0.025% by mass or less.
- Nb-based charcoal / nitride can contribute to the suppression of grain coarsening during brazing of Ni or Cu due to the pinning effect. Therefore, it is desirable to secure the C and N contents to such an extent that the corrosion resistance is not impaired.
- the total content of C and N is preferably 0.01% or more.
- each element is C: 0.005% by mass or more.
- N It is desirable to ensure 0.005 mass% or more.
- Si is an element that improves the pitting corrosion resistance of ferritic stainless steel. However, excessive Si content hardens the ferrite phase and causes deterioration of workability. Moreover, the wettability at the time of brazing Ni or Cu is deteriorated. Therefore, Si content shall be 3 mass% or less. From the viewpoint of improving corrosion resistance, the Si content is preferably more than 0.1%. The Si content is preferably in the range of 0.2 to 2.5% by mass, and the upper limit can be regulated to 1.5% by mass.
- Mn is used as a deoxidizer for stainless steel.
- Mn lowers the Cr concentration in the passive film and causes a decrease in corrosion resistance. Therefore, in the present invention, the Mn content is preferably low, and the content is defined as 2% by mass or less. Since some amount of Mn is unavoidable in the stainless steel made from scrap, it is necessary to manage it so that it is not excessively contained.
- P P is desirable to be low because it impairs the toughness of the base metal and brazed part.
- dephosphorization by refining is difficult in the production of Cr-containing steel, excessively increasing the cost, such as careful selection of raw materials, is required to minimize the P content. Therefore, in the present invention, the P content up to 0.05% by mass is allowed, as in the general ferritic stainless steel.
- S is an element that inhibits corrosion resistance by forming MnS that is likely to be the starting point of pitting corrosion, and when the S content is high, hot cracking of the brazed portion is likely to occur, so the S content is 0.03. It is defined as mass% or less.
- the Cr is a main constituent element of the passive film and brings about improvement of local corrosion properties such as pitting corrosion resistance and crevice corrosion resistance.
- the Cr content needs to be 11% or more.
- the Cr content is 11 to 30%, preferably 17 to 26% by mass.
- Nb is an important element in the present invention. As described above, Nb is excellent in repassivation ability in terms of corrosion resistance, and effectively acts to suppress grain coarsening during brazing of Ni and Cu. In addition to the drag effect of solute Nb, the pinning effect by Nb charcoal / nitride works effectively. In order to fully exhibit these effects, it is important to secure the Nb content at 0.15% by mass or more after regulating the C and N contents to the above ranges. In particular, it is effective to increase the Nb content to suppress grain coarsening during brazing of Ni and Cu, preferably 0.3% or more, more preferably 0.4% or more, and even more preferably 0.5%. % Nb content is desirable.
- the Nb content is limited to a range of 0.8% by mass or less. Further, when Nb is 0.15 to 0.3% by mass, a relatively low brazing temperature of 1000 ° C. has an effect of suppressing grain growth, but in order to stabilize the effect, composite addition with Ti is desirable.
- Mo is an effective element for improving the corrosion resistance level together with Cr, and it is known that the effect of improving the corrosion resistance increases as the Cr content increases.
- Mo, Cu, V, and W improve the acid resistance of stainless steel and improve the corrosion resistance. Furthermore, it is effective in preventing the coarsening of ferrite grains at the brazing temperature. Mo, V and W have a drag effect due to solid solution and a pinning effect due to precipitates, and Cu has a pinning effect due to precipitation as its own ⁇ Cu phase. Therefore, in the present invention, it is preferable to add at least one of these elements. In particular, it is effective to secure a total content of these elements of 0.05% by mass or more. However, when these elements are added excessively, the hot workability is adversely affected. As a result of various studies, when adding one or more of Mo, Cu, V, and W, the total content needs to be suppressed to 4% by mass or less. *
- Ti can form a fine Ti-based carbonitride having a strong affinity with C and N like Nb, and an effect of suppressing crystal grain growth during brazing can be expected.
- Al is effective as a deoxidizing agent, and suppresses a decrease in corrosion resistance when oxidized by brazing due to the combined addition with Ti. In particular, it is effective when the total content of Ti and Al is 0.03% or more. However, if any of these elements is contained in a large amount, it causes a decrease in hot workability and surface characteristics. In addition, since these elements are easily oxidizable elements, a strong oxide film may be formed on the surface of the steel material by heating during finish annealing or brazing, and the oxide film may cause brazing during brazing.
- the flow may become worse or the bonding strength after brazing may be reduced.
- the oxide film of other elements is removed by the reducing action of Zn contained in the braze, but Ti and Al have higher affinity with oxygen than Zn, so these oxide films are removed. I can't.
- the total content when adding one or more of Ti and Al, the total content (when Zr is contained, the total content of Ti, Al, and Zr) in order to avoid problems due to the oxide film. It is necessary to suppress it to 0.4 mass% or less. In particular, it is effective to make the total content in the range of 0.03 to 0.3% by mass, and it is more preferable to set the total content to 0.03 to 0.25% by mass.
- Ni and Co are extremely effective in suppressing a decrease in toughness when ferrite crystal grains are coarsened during brazing.
- the effect of characterizing this toughness reduction is exhibited even when the average crystal grain size is not coarse (for example, when the average grain size of ferrite crystal grains is 500 ⁇ m or less). Therefore, one or more of these elements can be contained as necessary.
- it is more effective to secure a total content of Ni and Co of 0.5% by mass or more.
- excessive addition of Ni and Co is not preferable because it causes formation of an austenite phase at a high temperature range and adversely affects hot workability.
- Ferritic stainless steel having the above composition has no problems with respect to corrosion resistance in water environments with high concentrations of exhaust gas condensate and chlorine compared to austenitic steel types used in conventional heat exchanger members Confirmed to be level. Moreover, the grain growth inhibitory effect and the brazing property on the grain coarsening during Ni and Cu brazing are simultaneously improved.
- the ferritic stainless steel of the present invention can be produced in the same manner as a general ferritic stainless steel after melting a steel having the composition specified in the present invention. At that time, it is preferable to control the maximum diameter and volume ratio of the precipitate so that the pinning effect for suppressing the coarsening of crystal grains is sufficiently exhibited.
- the ferritic stainless steel of the present invention can be made into a steel sheet by a method including hot rolling ⁇ cold rolling ⁇ finish annealing.
- hot rolling and finish annealing are performed so as to satisfy the following conditions [1] and [2]
- the precipitation distribution form in which the pinning effect is excellent that is, the maximum diameter d of the precipitate is obtained.
- the volume fraction f of the precipitate is 0.05% or more and 0.25 ⁇ m or less.
- the coiling temperature is set to less than 750 ° C.
- finish annealing the average rate of temperature increase from 600 ° C. to the maximum temperature Tm in the temperature raising process is 10 ° C./s or more, and the average cooling rate from Tm to 600 ° C. is 10 ° C./s in the cooling process. That's it.
- brazing a steel plate made of the ferritic stainless steel of the present invention into a stainless steel joined body various members such as a heat exchanger member can be obtained.
- the brazing material to be used.
- a known brazing material such as Ni brazing, Cu brazing, phosphor copper brazing, brass brazing, silver brazing can be used.
- the ferritic stainless steel of the present invention suppresses coarsening of crystal grains when heated at a high temperature, it is particularly suitable for brazing using a brazing material having a high brazing temperature such as phosphor copper brazing or brass brazing. Is advantageous.
- the brazing method there is no limitation on the brazing method, and a known method such as torch brazing can be employed.
- the surface oxide film is formed using a flux mainly composed of hydrofluoric acid and boric acid, as in general stainless steel. Can be removed and torch brazed. At that time, if the conditions of [3] and [4] are satisfied for the maximum temperature and heating time of the base material during brazing, the pinning effect due to precipitates can be effectively exhibited, It is possible to obtain a stainless steel joined body excellent in strength characteristics in which the average crystal grain size of the base material matrix is suppressed to 500 ⁇ m or less. [3] The maximum temperature reached by the base material during brazing is less than 1000 ° C. [4] The heating time during brazing is less than 3 minutes.
- Stainless steel having the chemical composition shown in Table 1 was melted, and a hot-rolled sheet having a thickness of 3 mm was produced by hot rolling. Thereafter, the plate thickness was 1.0 mm by cold rolling, the finish annealing was performed at the maximum temperature Tm: 1000 to 1070 ° C., the holding time 1 to 60 seconds, and pickling was performed to obtain a test material. Hot rolling and finish annealing were all performed under the conditions satisfying the above [1] and [2] except for the steels 19 and 20 of the present invention.
- the present invention steel 19 is made of steel having the same chemical composition as the present invention steel 10, but the coiling temperature in hot rolling was set to 880 ° C.
- the present invention steel 20 is made of steel having the same chemical composition as the present invention steel 15, but the cooling temperature from Tm to 600 ° C. was set to 1 ° C./s in the cooling process during finish annealing.
- the comparative steel 6 is an austenitic stainless steel.
- a solder covering ratio of 50% or more was evaluated as A, 20% or more and less than 50% was evaluated as B, and less than 20% was evaluated as C.
- Crystal grain size after brazing heat treatment About the test piece which evaluated the brazing property mentioned above, the metal structure (4) of the cross section (refer FIG. 1) was observed with the optical microscope. Etching was performed with a mixed acid of hydrofluoric acid and nitric acid. The crystal grain size was determined by the intercept method, and those with 200 ⁇ m or less were evaluated as A, those with 200 ⁇ m or more and 500 ⁇ m or less as B, and those with 500 ⁇ m or more as C, and A and B were determined to be acceptable.
- the brazing temperature is about 900 ° C., but the temperature of the brazing material rises to 1000 ° C. or more due to preheating, especially near the surface where the flame directly hits. Then, it may reach about 1100 ° C. Further, thermal history may be further added due to overheating or re-brazing due to poor bonding. Therefore, a 30 mm ⁇ 80 mm test piece was cut out from each steel material and heated at 1100 ° C. for 10 minutes as a heat treatment corresponding to torch brazing.
- the end face of the test piece after the heat treatment was polished, etched with a mixed acid prepared using hydrofluoric acid and nitric acid, observed with an optical microscope, and the average crystal grain size was determined by a section method.
- a having an average crystal grain size of 200 ⁇ m or less is A (having a very good effect of suppressing coarsening)
- B is more than 200 ⁇ m and 500 ⁇ m or less of B (having an excellent effect of suppressing coarsening), and is exceeding 500 ⁇ m and not more than 1000 ⁇ m.
- C there was an effect of suppressing coarsening
- those exceeding 1000 ⁇ m were evaluated as D (the effect of suppressing coarsening was not sufficient).
- B evaluation was obtained, even if it uses for uses, such as a heat exchanger member and a piping member, it is thought that the characteristic which does not have a problem practically is shown.
- Test brazing with brass brazing material A test piece of 30 mm ⁇ 80 mm was cut out from each steel material having a plate thickness of 1 mm, overlapped with a stacking allowance (8) of 4 mm as shown in FIG. 3, and joined by performing torch brazing from one side (9) using a flux. .
- As the brazing material brass brazing (BCuZn-1 (60Cu-0.1Sn-Zn alloy) wire) is used, and as the flux, H 3 BO 4 -KB 4 generally used in brazing stainless steel. An O 7 -KF-KBF 4 system was used.
- the test piece joined in this way was pulled by a tensile tester until it broke in the longitudinal direction. If the torch brazing is good, the test piece will break at the base metal part, so the one that broke at the base metal part is ⁇ (good torch brazing), the one that broke at the brazing part Was evaluated as x (poor brazing property was poor).
- Table 3 shows the results of Ni / Cu brazing performance, crystal grain size after Ni / Cu brazing heat treatment, condensed water test of Ni brazed heat treated material, and crevice corrosion condensed water test of Ni brazed heat treated material in water environment.
- Table 4 shows the crystal grain size after heat treatment equivalent to torch brazing, torch brazing with a brass brazing material, and outer surface corrosion resistance after torch brazing.
- the ferritic stainless steel of the present invention steel has Ni and Cu brazing properties that have been used in conventional heat exchanger members, suppresses crystal grain coarsening, and has condensed gas composition. It was confirmed that it has excellent corrosion resistance in water and water environments and can have sufficient characteristics as a heat exchanger member.
- comparative steels 1 and 2 have a small amount of Nb, and there is no effect of Nb-based precipitates or solute Nb during brazing, so that grain growth is likely to occur. Since the comparative steel 1 has a large amount of carbon, it is sensitized by precipitation of carbide during brazing cooling and requires a problem in corrosion resistance. Moreover, since the comparative example 2 had high P and Mo, its toughness was low, and since there was also much nitrogen amount, it was inferior to the corrosion resistance in the condensed water of the gas composition by sensitization, or water environment. Furthermore, since there is much Ti content, brazing property is disqualified.
- the comparative steel 3 also has problems in manufacturability such as a decrease in ductility due to martensite phase formation due to austenite formation due to an increase in the amount of Mn, and a decrease in toughness due to an increase in strength at high Nb.
- the comparative steel 4 was inferior in the brazing property of Ni or Cu due to the problem of the surface condition due to excessive addition of Al.
- Comparative Steels 1 and 2 had a low Nb content, and the ferrite grain coarsening was not sufficiently suppressed. Since Comparative Example 1 had a high C content, sensitization occurred due to heating during torch brazing, and the corrosion resistance was also poor. However, when brass brazing was used as the brazing material, decarburization occurred due to C in the steel becoming CO gas, so that the torch brazing with the brass brazing material was good. In addition, Comparative Steels 2 and 4 were inferior in bonding strength after torch brazing because of the large total content of Ti + Al. In Comparative Example 5, the Cr content was low, and the outer surface corrosion resistance did not reach the level required for use in piping member applications.
- the ferritic stainless steel according to the present invention has good corrosion resistance while preventing deterioration of ductility and toughness due to coarsening of crystal grains during brazing, it is used for brazing of heat exchanger members and piping members. In addition, it can be suitably used for materials of various members that require corrosion resistance.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- General Engineering & Computer Science (AREA)
- Heat Treatment Of Sheet Steel (AREA)
- Heat Treatment Of Steel (AREA)
Abstract
Description
(1)Niろう付け性やCuろう付け性、さらには安価な黄銅ろう等を用いたトーチろう付け性等の各種ろう付け性が良好であること。
さらに、ろう付けを施す部材が、熱交換器部材(冷媒配管や水配管)等の金属部材である場合には、以下のような特性も要求される。
(2)燃焼ガスから排出される凝結水での硝酸や硫酸環境での耐食性や塩素濃度が高い水環境での耐すきま腐食などの耐食性が良好であること。
これらの特性を有し、良好なろう付け性を持つ材料として、特許2642056号ではフェライト系ステンレス鋼の使用が検討されている。
固溶Nb量を表す下記A値が0.10以上
A = Nb - (C×92.9/12 + N×92.9/14)
であることを特徴とする、
フェライト系ステンレス鋼を適用することにより、達成される。
また、フェライト系ステンレス鋼中の析出物の最大径dが0.25μm以下、析出物の体積率fが0.05%以上であることが好ましい。
上記フェライト系ステンレス鋼には、その他必要に応じて、
(1) Mo、Cu、VおよびWの1種以上を合計4%以下の範囲、
(2) Ti、Alの1種以上を合計0.4%以下の範囲、
(3) NiおよびCoの1種以上を合計5%以下の範囲
(4) REM(希土類元素)およびCaの1種類以上を合計0.2%以下の範囲、
でそれぞれ選択的に含有することができる。
なお、ステンレス鋼がTiを含有する場合、固溶Nb量は下記A’値で表されるので、A’値が0.10以上であればよい。
A’ = Nb - C×92.9/2/12
〔ドラッグ効果〕
結晶粒が成長するときには結晶粒界の移動が伴う。結晶粒界に集積しやすい固溶元素や不純物元素がマトリクス中に含まれていると、結晶粒界は、それらの原子を引き連れて移動しなくてはならず、その移動が困難になる(ドラッグ効果)。本発明者らは、このドラッグ効果に着目し、結晶粒界にあえて固溶元素を存在させ結晶粒界の移動を阻害することにより、結晶粒成長が抑制できることを見出した。そして、フェライト系ステンレス鋼の高温での結晶粒成長について鋭意研究した結果、フェライト系ステンレス鋼の場合には、固溶元素の中でもとりわけ固溶Nbが結晶粒成長の抑制に有効であることを見出した。
もっとも、NbはC、Nと結合しやすい元素であるため、ステンレス鋼中のNbのうち、固溶Nbとなり得るのは、Nb炭窒化物生成に用いられた残りのNbである。したがって、ステンレス鋼中の固溶可能なNb量は、下記式のようにA値を用いて表すことができる。
A = Nb - (C×92.9/12 + N×92.9/14)
なお、上式において、C、Nは、それぞれ、ステンレス鋼中のC、Nの含有量(質量%)を表す。
A’ = Nb - C×(92.9/12)/2
A値、A’値は、0.2以上であることが好ましく、0.25以上であることがさらに好ましい。
金属マトリクス中に析出物が微細分散しているとき、それらは転位の運動の障害となりいわゆる析出強化現象を引き起こすことが知られているが、高温時にはこれらの析出物が粒界移動を抑制することが分かった(ピン止め効果)。
ピン止め効果の度合については、析出物の最大径をd(μm)、析出物の体積率(%)をfとして、d/fで表すことができる。析出物が小さく、量が多いほうがピン止め効果は高い。発明者らは析出物の体積率fが0.05~0.20%の鋼を用い、析出物の直径d(μm)を変えた場合の結晶粒粗大化を評価し、d/fが5以上になるとろう付け処理によってステンレス鋼の結晶粒径が500μm以上になることを発見した。したがって、本発明においては、d/fが5以下になるように析出物の量と径を制御することが好ましい。言い換えると、個々の析出物の粒子径が小さく、かつ、析出物のトータルの体積率が大きくするほど、ピン止め効果が大きくなる。
なお析出物を微細に分散させるためには、ステンレス鋼の製造時における昇温中や冷却中の析出物粗大化を抑制することが重要である。熱延工程では巻取り温度を750℃未満とし、焼鈍工程では600℃から最高到達材温Tmまでの平均昇温速度を10℃/s以上、かつTmから600℃までの平均冷却速度を10℃/s以上にコントロールすることにより、最大径が0.25μm以下の析出物を得られることがわかった。この場合、体積率fが0.05以上であれば本発明で必要なピン止め効果が得られる。
したがって、本発明においては、析出物の最大径dが0.25μm以下、析出物の体積率fが0.05%以上となるように制御することが好ましい。
ピン止め効果に特に有効な析出物としては、Nb系析出物が挙げられ、例えば、Nb炭化物、Nb窒化物、Nb炭窒化物(以下、これらをまとめて「Nb系炭・窒化物」ということもある。)や、Fe2Nb(Laves相)、Fe3NbC等が挙げられる。
また、Ni、CoならびにCuは、ろう付け時にフェライト粒が粗大化した時の靭性低下の抑制に極めて有効であることがわかった。一方、Ti、Al、Zr、REM、CaはNiろうやCuろう付けを行う際に、鋼材表面におけるろう材の流れをを悪くする要因を有していることが明らかになった。これは、ろう付けの加熱時に、鋼材表面にこれら元素の酸化物が形成されやすいことが原因ではないかと考えられる。ただし、後述するようにこれらの元素の含有量を適正範囲に規制すれば問題ない。
Alは、脱酸剤として有効であり、Tiとの複合添加によってろう付けで酸化した時の耐食性低下を抑制する。特に、TiとAlの合計含有量を0.03%以上とすると効果的である。
しかし、これらの元素はいずれも、多量に含有させると熱間加工性や表面特性の低下を招く要因となる。また、これらの元素は易酸化性元素であるため、仕上焼鈍やろう付けを行う際の加熱により、鋼材表面に強固な酸化皮膜を形成することがあり、その酸化皮膜によりろう付け時のろうの流れが悪くなるなったり、ろう付け後の接合強度が低下することがある。黄銅ろうを用いる場合、ろうに含有されるZnの還元作用によってその他の元素の酸化皮膜は除去されるが、Ti、AlはZnよりも酸素との親和力が強いため、これらの酸化皮膜を除去することができない。検討の結果、Ti、Alの1種以上を添加する場合は、酸化皮膜による問題を回避するためにその合計含有量(Zrを含有する場合には、Ti、Al及びZrの合計含有量)を0.4質量%以下に抑える必要がある。特に、その合計含有量を0.03~0.3質量%の範囲にすることが効果的であり、0.03~0.25質量%とすることがより望ましい。
[1]熱間圧延において、巻取温度を750℃未満とする。
[2]仕上焼鈍において、昇温過程で600℃から最高到達温度Tmまでの平均昇温速度を10℃/s以上とし、かつ冷却過程でTmから600℃までの平均冷却速度を10℃/s以上とする。
[3]ろう付け時の基材の最大到達温度を1000℃未満とする。
[4]ろう付け時の加熱時間を3分未満とする。
熱間圧延および仕上焼鈍は、本発明鋼19、20を除いて、すべて前述の[1]および[2]を満たす条件で行った。本発明鋼19は、本発明鋼10と同じ化学組成の鋼からなる
が、熱間圧延での巻き取り温度を880℃とした。本発明鋼20は、本発明鋼15と同じ化学組成の鋼からなるが、仕上焼鈍の際の冷却過程において、Tmから600℃までの冷却温度を1℃/sとした。
なお、比較鋼6はオーステナイト系ステンレス鋼である。
「析出物の最大径、体積率f」
各鋼材を切断し、その断面を電解研磨した表面をSEMにより観察した。観察視野の総面積が2×10-2mm2となるまで観察を続け、その間に観察した析出物のうち、粒子径が最も大きい析出物の粒子径を最大径d(μm)とした。
また、同様にして、観察視野2×10-2mm2分の断面を観察し、その観察視野の中に存在したすべての析出物の面積S(mm2)を画像処理により測定し、以下の式により体積率fを算出した。
f(%)=S/(2×10-2)×100
なお、析出物の判別は、EDXによる面分析を行い、Nb、Ti、Mo、Cu、V又はWの検出強度がマトリクス部分より高い部分を析出物とみなすことにより行った。得られた値は表1に示した。
まず図1に示すようなサイズの異なる2枚の試験片(下側35×25mm、上側20×25mm)の間に厚さ0.3mmのペースト状NiとCuろうを塗布した。これを水平に保ったまま、下表の条件で真空中でろう付け処理を施した。
上述のろう付け性を評価した試験片について、その断面(図1参照)の金属組織(4)を光学顕微鏡で観察した。エッチングは弗酸+硝酸の混酸で行った。結晶粒径は切片法で求め、200μm以下のものをA、200μm越え500μm以下のものB、500μm越えるものをCと評価し、AとBを合格と判定した。
上述のろう付け性を評価した試験片について、ろう材が回りこんできた上側20×25mmの上面を#600研磨した後、図2に示すように、この試験片(5)を200mlビーカー(6)内に保持した給湯ガスの組成に含まれる成分を想定した模擬ドレン水(7)100ml(100ppmHNO3、20ppmH2SO4、1ppmCl-)に浸漬して(201)、130℃の環境試験機内に液が乾燥する約7時間置いた浸漬試験を行い(202)、次いで水洗を行う、というサイクルを10回繰り返して10サイクルの試験を実施し、ステンレス素材ならびにろう材での侵食の有無を侵食の有無で評価した。
上述のろう付け性を評価した試験片について、ろう材が回りこんできた上側20×25mmの上面を#600研磨した後、2000ppmCl-+10ppmCuに24時間浸漬した。その際、最大侵食深さが0.1mm未満を○、0.1mm越えを×とした。
黄銅ろうを用いてトーチろう付けを行う場合、ろう付け温度は900℃程度であるが、予備加熱等により、被ろう付け材の温度は1000℃以上に上昇し、特に、炎が直接当たる表面近傍では1100℃程度にまで達することもある。また、オーバーヒートや、接合不良による再ろう付けなどにより、更に熱履歴が加わることもある。そこで、各鋼材から30mm×80mmの試験片を切り出し、トーチろう付けに相当する熱処理として、1100℃で10分間加熱した。熱処理後の試験片の端面を研磨し、フッ酸と硝酸を用いて調製した混酸でエッチングを施し、光学顕微鏡で観察し、切片法により平均結晶粒径を求めた。
平均結晶粒径が200μm以下のものをA(きわめて良好な粗大化抑制効果があった)、200μmを超え500μm以下のものをB(良好な粗大化抑制効果があった)、500μmを超え1000μm以下のものをC(粗大化抑制効果があった)、1000μmを超えるものをD(粗大化抑制効果が充分でなかった)と評価した。B評価が得られたものについては、熱交換器部材や配管部材等の用途に使用しても実用上問題ない特性を示すと考えられる。
板厚1mmの各鋼材から30mm×80mmの試験片を切り出し、図3に示すように重ね代(8)を4mmにして重ね合わせ、フラックスを用いて片側(9)からトーチろう付けを行い接合した。なお、ろう材としては、黄銅ろう(BCuZn-1(60Cu-0.1Sn-Zn合金)のワイヤー)を、フラックスとしては、ステンレス鋼のろう付けにおいて一般に使用される、H3BO4-KB4O7-KF-KBF4系のものを使用した。このようにして接合された試験片を、引張試験機により長手方向に破断するまで引っ張った。トーチろう付けが良好である場合には、試験片は母材部で破断することになるので、母材部で破断したものを○(トーチろう付け性が良好)、ろう材部で破断したものを×(トーチろう付け性が不良)と評価した。
本発明のステンレス鋼を配管部材に適用した場合の管外面の耐食性を評価するために、上記のトーチろう付け相当の熱処理を施した試験片に対して、塩酸噴霧→乾燥→湿潤を1サイクルとする塩乾湿試験を繰り返し10サイクル行い、発銹面積率を測定した。発銹面積率は、試験後の外観写真を撮影し、端面を除く発銹部分の面積を、試料全体の面積で除することにより求めた。
発銹面積率が1%以下のものを○(外面耐食性が良好)、1%を超えるものを×(外面耐食性が不良)と評価した。
ただし、本発明鋼19、20は、極端な製造条件を設定し、析出物の体積率fを非常に小さく、または、析出物の最大径を非常に大きくしたため、フェライト結晶粒の粗大化抑制効果が低下していた。
比較例5は、Cr含有量が少なく、外面耐食性が配管部材用途に用いるのに必要な水準に達していなかった。
2 下側試験片
3 ろう材
4 金属組織観察の対象部分
5 試験片
51 表面
52 界面
6 200mlビーカー
7 模擬ドレン水
8 重ね代
9 トーチろう付けした方向
Claims (11)
- 質量%で、
C:0.03%以下、
Si:3%以下、
Mn:2%以下、
P:0.05%以下、
S:0.03%以下、
Cr:11~30%、
Nb:0.15~0.8%、
N:0.03%以下
を含有し、
残部がFeおよび不可避的不純物からなり、
下記A値が0.10以上であるフェライト系ステンレス鋼。
A = Nb - (C×92.9/12 + N×92.9/14) - 質量%で、
C:0.03%以下、
Si:3%以下、
Mn:2%以下、
P:0.05%以下、
S:0.03%以下、
Cr:11~30%、
Nb:0.15~0.8%、
N:0.03%以下
を含有し、
残部がFeおよび不可避的不純物からなり、Tiの含有量(モル)がCとNの含有量(モル)の合計より多く、
下記A’値が0.10以上であるフェライト系ステンレス鋼。
A’ = Nb - C×(92.9/12)/2 - さらに、Mo、Cu、VおよびWの1種以上を合計4%以下の範囲で含有する請求項1又は2に記載のフェライト系ステンレス鋼。
- さらに、Ti、Alの1種以上を合計0.4%以下の範囲で含有する、請求項1~3いずれかに記載のフェライト系ステンレス鋼。
- さらに、NiおよびCoの1種以上を合計5%以下の範囲で含有する請求項1~4のいずれかに記載のフェライト系ステンレス鋼。
- CおよびNの合計含有量が0.01%以上である請求項1~5いずれかに記載のフェライト系ステンレス鋼。
- Siの含有量の下限値が0.1%を超える請求項1~6いずれかに記載のフェライト系ステンレス鋼。
- 熱交換器部材製造用又はトーチろう付け部材製造用である請求項1~7いずれかに記載のフェライト系ステンレス鋼。
- 析出物の最大径dが0.25μm以下で、析出物の体積率fが0.05%以上である、 請求項1~8いずれかに記載のフェライト系ステンレス鋼からなる鋼板。
- 請求項1~9いずれかに記載のフェライトス系テンレス鋼からなる鋼板を含むステンレス鋼接合体であって、前記鋼板がろう付けされている、ステンレス鋼接合体。
- 請求項1~10いずれかに記載のフェライト系ステンレス鋼を用意する工程と、
巻取温度を750℃未満として熱間圧延を行う工程と、
昇温過程における600℃から最高到達温度Tmまでの平均昇温速度を10℃/s以上、却過程における最高到達温度Tmから600℃までの平均冷却速度を10℃/s以上として仕上焼鈍を行う工程と、
を含む、フェライト系ステンレス鋼板の製造方法。
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
BRPI0912550-7A BRPI0912550B1 (pt) | 2008-05-12 | 2009-05-11 | Aço inoxidável ferrítico, folha de aço composta com mesmo, junção de aço inoxidável, e, processo para produzir uma folha de aço inoxidável ferrítico |
ES09746562.9T ES2671376T3 (es) | 2008-05-12 | 2009-05-11 | Procedimiento de producción de acero inoxidable ferrítico |
EP09746562.9A EP2280090B1 (en) | 2008-05-12 | 2009-05-11 | Ferritic stainless steel and production method |
CN200980116784.1A CN102027146B (zh) | 2008-05-12 | 2009-05-11 | 铁素体系不锈钢 |
US12/936,794 US9249475B2 (en) | 2008-05-12 | 2009-05-11 | Ferritic stainless steel |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2008124462 | 2008-05-12 | ||
JP2008-124462 | 2008-05-12 | ||
JP2009-083001 | 2009-03-30 | ||
JP2009083001A JP5420292B2 (ja) | 2008-05-12 | 2009-03-30 | フェライト系ステンレス鋼 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2009139355A1 true WO2009139355A1 (ja) | 2009-11-19 |
Family
ID=41318723
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2009/058778 WO2009139355A1 (ja) | 2008-05-12 | 2009-05-11 | フェライト系ステンレス鋼 |
Country Status (7)
Country | Link |
---|---|
US (1) | US9249475B2 (ja) |
EP (1) | EP2280090B1 (ja) |
JP (1) | JP5420292B2 (ja) |
CN (1) | CN102027146B (ja) |
BR (1) | BRPI0912550B1 (ja) |
ES (1) | ES2671376T3 (ja) |
WO (1) | WO2009139355A1 (ja) |
Families Citing this family (25)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
AU614904B2 (en) * | 1989-07-31 | 1991-09-12 | American Telephone And Telegraph Company | Measuring and controlling the thickness of a coating on a elongated article |
JP2010053811A (ja) * | 2008-08-29 | 2010-03-11 | Maruyasu Industries Co Ltd | 排気ガス熱交換器 |
JP5311942B2 (ja) * | 2008-09-10 | 2013-10-09 | 日新製鋼株式会社 | ろう付け用ステンレス鋼 |
JP5349153B2 (ja) * | 2009-06-15 | 2013-11-20 | 日新製鋼株式会社 | ろう付け用フェライト系ステンレス鋼材および熱交換器部材 |
JP5610796B2 (ja) * | 2010-03-08 | 2014-10-22 | 新日鐵住金ステンレス株式会社 | 炭化水素燃焼排ガスから発生する凝縮水環境における耐食性に優れるフェライト系ステンレス鋼 |
CN103958717B (zh) | 2011-11-30 | 2016-05-18 | 杰富意钢铁株式会社 | 铁素体系不锈钢 |
DE102013101631A1 (de) * | 2012-03-06 | 2013-09-12 | Babcock Borsig Steinmüller Gmbh | Korrosionsbeständiger Wärmetauscher |
JP5973759B2 (ja) * | 2012-03-23 | 2016-08-23 | 日新製鋼株式会社 | 溶融硝酸塩の貯蔵容器または輸送配管用フェライト系ステンレス鋼および溶融硝酸塩を蓄熱媒体とする蓄熱システム |
KR101688760B1 (ko) | 2013-03-14 | 2016-12-21 | 닛폰 스틸 앤드 스미킨 스테인레스 스틸 코포레이션 | 시효 열처리 후의 강도 증가가 작은 페라이트계 스테인리스 강판 및 그 제조 방법 |
US9499889B2 (en) | 2014-02-24 | 2016-11-22 | Honeywell International Inc. | Stainless steel alloys, turbocharger turbine housings formed from the stainless steel alloys, and methods for manufacturing the same |
WO2016068291A1 (ja) * | 2014-10-31 | 2016-05-06 | 新日鐵住金ステンレス株式会社 | 耐排ガス凝縮水腐食性とろう付け性に優れたフェライト系ステンレス鋼及びその製造方法 |
JP6159775B2 (ja) | 2014-10-31 | 2017-07-05 | 新日鐵住金ステンレス株式会社 | 耐排ガス凝縮水腐食性とろう付け性に優れたフェライト系ステンレス鋼及びその製造方法 |
MX2017011033A (es) | 2015-03-26 | 2017-12-04 | Nippon Steel & Sumikin Sst | Acero inoxidable que tiene excelente capacidad de broncesoldadura. |
JP6157664B1 (ja) * | 2016-02-23 | 2017-07-05 | 新日鐵住金ステンレス株式会社 | フェライト系ステンレス鋼およびその製造方法 |
CN109563596A (zh) * | 2016-09-02 | 2019-04-02 | 杰富意钢铁株式会社 | 铁素体系不锈钢 |
CN106591736B (zh) * | 2016-12-13 | 2018-08-21 | 山西太钢不锈钢股份有限公司 | 高强低铬不锈钢及其热处理方法 |
JP6871045B2 (ja) * | 2017-03-31 | 2021-05-12 | 日鉄ステンレス株式会社 | ろう付け性と耐食性に優れたフェライト系ステンレス鋼およびNiろう付け接合部材 |
JP6841150B2 (ja) * | 2017-04-28 | 2021-03-10 | 日本製鉄株式会社 | 耐熱部材用フェライト系ステンレス鋼板 |
CN107654544B (zh) * | 2017-08-31 | 2021-11-05 | 聊城市德通交通器材制造有限公司 | 缓速器用机油散热器 |
US10428713B2 (en) | 2017-09-07 | 2019-10-01 | Denso International America, Inc. | Systems and methods for exhaust heat recovery and heat storage |
KR102109898B1 (ko) * | 2018-06-26 | 2020-05-12 | 주식회사 포스코 | 진동 감쇄능이 우수한 저Cr 페라이트계 스테인리스강 및 그 제조방법 |
KR102247418B1 (ko) * | 2018-12-19 | 2021-05-03 | 엘지전자 주식회사 | 동합금 스테인리스 배관과, 이를 포함하는 공기 조화기 및 그 제조방법 |
SE543405C2 (en) * | 2019-05-29 | 2021-01-05 | Alfa Laval Corp Ab | Method for joining metal parts |
KR102421514B1 (ko) * | 2019-08-26 | 2022-07-20 | 주식회사 경동나비엔 | 직수의 열교환 방법, 열교환기 및 물 가열기 |
US11492690B2 (en) | 2020-07-01 | 2022-11-08 | Garrett Transportation I Inc | Ferritic stainless steel alloys and turbocharger kinematic components formed from stainless steel alloys |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH034617B2 (ja) * | 1980-08-08 | 1991-01-23 | Allegheny Int Inc | |
JP2642056B2 (ja) | 1994-04-22 | 1997-08-20 | 日本冶金工業株式会社 | 熱交換器用フェライト系ステンレス鋼 |
WO2009084526A1 (ja) * | 2007-12-28 | 2009-07-09 | Nippon Steel & Sumikin Stainless Steel Corporation | ろう付け性に優れたフェライト系ステンレス鋼 |
Family Cites Families (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4461811A (en) * | 1980-08-08 | 1984-07-24 | Allegheny Ludlum Steel Corporation | Stabilized ferritic stainless steel with improved brazeability |
JPH0748648B2 (ja) | 1989-06-01 | 1995-05-24 | 三菱電機株式会社 | 電子スイッチ装置 |
JPH06102817B2 (ja) | 1990-03-28 | 1994-12-14 | 新日本製鐵株式会社 | ろう付け後の靭性および耐食性に優れたフェライト系ステンレス鋼 |
JP3411644B2 (ja) * | 1993-10-29 | 2003-06-03 | Jfeスチール株式会社 | 耐リジング性に優れるフェライト系ステンレス鋼板の製造方法 |
US5851316A (en) * | 1995-09-26 | 1998-12-22 | Kawasaki Steel Corporation | Ferrite stainless steel sheet having less planar anisotropy and excellent anti-ridging characteristics and process for producing same |
JP4237904B2 (ja) * | 2000-01-11 | 2009-03-11 | 新日本製鐵株式会社 | 母材ならびに溶接継手のクリープ強度と靭性に優れたフェライト系耐熱鋼板およびその製造方法 |
EP1219719B1 (en) * | 2000-12-25 | 2004-09-29 | Nisshin Steel Co., Ltd. | A ferritic stainless steel sheet good of workability and a manufacturing method thereof |
KR100762151B1 (ko) * | 2001-10-31 | 2007-10-01 | 제이에프이 스틸 가부시키가이샤 | 딥드로잉성 및 내이차가공취성이 우수한 페라이트계스테인리스강판 및 그 제조방법 |
JP3995978B2 (ja) * | 2002-05-13 | 2007-10-24 | 日新製鋼株式会社 | 熱交換器用フェライト系ステンレス鋼材 |
JP3886933B2 (ja) * | 2003-06-04 | 2007-02-28 | 日新製鋼株式会社 | プレス成形性,二次加工性に優れたフェライト系ステンレス鋼板及びその製造方法 |
US20060225820A1 (en) * | 2005-03-29 | 2006-10-12 | Junichi Hamada | Ferritic stainless steel sheet excellent in formability and method for production thereof |
JP4518834B2 (ja) * | 2004-05-12 | 2010-08-04 | 新日鐵住金ステンレス株式会社 | 加工性に優れた耐熱フェライト系ステンレス鋼板の製造方法 |
JP4749881B2 (ja) * | 2005-02-15 | 2011-08-17 | 新日鐵住金ステンレス株式会社 | 耐すきま腐食性に優れたフェライト系ステンレス鋼 |
KR101606946B1 (ko) * | 2008-02-07 | 2016-03-28 | 닛신 세이코 가부시키가이샤 | 고강도 스테인리스 강재 및 그 제조 방법 |
-
2009
- 2009-03-30 JP JP2009083001A patent/JP5420292B2/ja active Active
- 2009-05-11 CN CN200980116784.1A patent/CN102027146B/zh active Active
- 2009-05-11 US US12/936,794 patent/US9249475B2/en active Active
- 2009-05-11 ES ES09746562.9T patent/ES2671376T3/es active Active
- 2009-05-11 WO PCT/JP2009/058778 patent/WO2009139355A1/ja active Application Filing
- 2009-05-11 BR BRPI0912550-7A patent/BRPI0912550B1/pt active IP Right Grant
- 2009-05-11 EP EP09746562.9A patent/EP2280090B1/en active Active
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH034617B2 (ja) * | 1980-08-08 | 1991-01-23 | Allegheny Int Inc | |
JP2642056B2 (ja) | 1994-04-22 | 1997-08-20 | 日本冶金工業株式会社 | 熱交換器用フェライト系ステンレス鋼 |
WO2009084526A1 (ja) * | 2007-12-28 | 2009-07-09 | Nippon Steel & Sumikin Stainless Steel Corporation | ろう付け性に優れたフェライト系ステンレス鋼 |
Also Published As
Publication number | Publication date |
---|---|
EP2280090A4 (en) | 2015-08-19 |
BRPI0912550B1 (pt) | 2019-04-30 |
BRPI0912550A2 (pt) | 2017-10-17 |
EP2280090A1 (en) | 2011-02-02 |
CN102027146B (zh) | 2016-11-16 |
JP5420292B2 (ja) | 2014-02-19 |
US9249475B2 (en) | 2016-02-02 |
US20110033731A1 (en) | 2011-02-10 |
CN102027146A (zh) | 2011-04-20 |
JP2009299182A (ja) | 2009-12-24 |
EP2280090B1 (en) | 2018-03-21 |
ES2671376T3 (es) | 2018-06-06 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5420292B2 (ja) | フェライト系ステンレス鋼 | |
CA2762899C (en) | Ferritic stainless steel material for brazing and heat exchanger member | |
JP5264199B2 (ja) | フェライト系ステンレス鋼を用いたegrクーラー | |
JP7059357B2 (ja) | 二相ステンレスクラッド鋼板およびその製造方法 | |
JP6895787B2 (ja) | オーステナイト系ステンレス鋼、ろう付け構造体、ろう付け構造部品および排気ガス熱交換部品 | |
WO2011111871A1 (ja) | 耐酸化性に優れたフェライト系ステンレス鋼板並びに耐熱性に優れたフェライト系ステンレス鋼板及びその製造方法 | |
JP6858056B2 (ja) | 低比重フェライト系ステンレス鋼板およびその製造方法 | |
JP2005023353A (ja) | 高温水環境用オーステナイトステンレス鋼 | |
WO2011013193A1 (ja) | Egrクーラー用フェライト系ステンレス鋼およびegrクーラー | |
WO2005042793A1 (ja) | 耐食性に優れたラインパイプ用高強度ステンレス鋼管およびその製造方法 | |
JPWO2019189708A1 (ja) | 二相ステンレスクラッド鋼板及びその製造方法 | |
JP4265605B2 (ja) | 二相ステンレス鋼 | |
KR20200102489A (ko) | 내염해 부식성이 우수한 페라이트계 스테인리스강 | |
JPWO2019189707A1 (ja) | 二相ステンレスクラッド鋼板及びその製造方法 | |
JP5366498B2 (ja) | Cuめっきフェライト系ステンレス鋼板および多重巻き鋼管 | |
JP3269799B2 (ja) | 加工性、耐粒界腐食性および高温強度に優れるエンジン排気部材用フェライト系ステンレス鋼 | |
JP5786491B2 (ja) | Egrクーラー用フェライト系ステンレス鋼 | |
JP2017020054A (ja) | ステンレス鋼およびステンレス鋼管 | |
JP2004353041A (ja) | 高耐食二相ステンレス鋼 | |
CN113195762A (zh) | 铁素体不锈钢 | |
JP2003213379A (ja) | 耐食性に優れたステンレス鋼 | |
RU2808643C2 (ru) | Ферритная нержавеющая сталь | |
JP4775910B2 (ja) | 耐高温塩害腐食性に優れたオーステナイト系ステンレス鋼 | |
JP2005036313A (ja) | 二相ステンレス鋼 | |
JPH07145447A (ja) | 高温塩害特性などに優れたCr含有鋼 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WWE | Wipo information: entry into national phase |
Ref document number: 200980116784.1 Country of ref document: CN |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 09746562 Country of ref document: EP Kind code of ref document: A1 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 12936794 Country of ref document: US |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2009746562 Country of ref document: EP |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
ENP | Entry into the national phase |
Ref document number: PI0912550 Country of ref document: BR Kind code of ref document: A2 Effective date: 20101111 |