EP1299569B1 - Ferritic stainless steel for ferromagnetic parts - Google Patents
Ferritic stainless steel for ferromagnetic parts Download PDFInfo
- Publication number
- EP1299569B1 EP1299569B1 EP01951783A EP01951783A EP1299569B1 EP 1299569 B1 EP1299569 B1 EP 1299569B1 EP 01951783 A EP01951783 A EP 01951783A EP 01951783 A EP01951783 A EP 01951783A EP 1299569 B1 EP1299569 B1 EP 1299569B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- steel
- ferritic
- composition
- steels
- ferritic stainless
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 229910001220 stainless steel Inorganic materials 0.000 title claims abstract description 14
- 230000005294 ferromagnetic effect Effects 0.000 title claims description 5
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 69
- 239000010959 steel Substances 0.000 claims abstract description 69
- 239000000203 mixture Substances 0.000 claims abstract description 21
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 16
- 229910052791 calcium Inorganic materials 0.000 claims abstract description 12
- 229910052717 sulfur Inorganic materials 0.000 claims abstract description 11
- 239000012535 impurity Substances 0.000 claims abstract description 8
- 229910052742 iron Inorganic materials 0.000 claims abstract description 8
- 238000004519 manufacturing process Methods 0.000 claims abstract description 6
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 6
- 229910052719 titanium Inorganic materials 0.000 claims abstract description 6
- 229910052802 copper Inorganic materials 0.000 claims abstract description 5
- 229910052758 niobium Inorganic materials 0.000 claims abstract description 5
- 229910052698 phosphorus Inorganic materials 0.000 claims abstract 4
- 239000011575 calcium Substances 0.000 claims description 26
- 230000005291 magnetic effect Effects 0.000 claims description 17
- 238000000137 annealing Methods 0.000 claims description 10
- 229910052760 oxygen Inorganic materials 0.000 claims description 9
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 claims description 8
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 6
- 238000000034 method Methods 0.000 claims description 6
- 239000001301 oxygen Substances 0.000 claims description 6
- 238000001816 cooling Methods 0.000 claims description 5
- 235000008733 Citrus aurantifolia Nutrition 0.000 claims description 4
- 235000011941 Tilia x europaea Nutrition 0.000 claims description 4
- 229910052661 anorthite Inorganic materials 0.000 claims description 4
- GWWPLLOVYSCJIO-UHFFFAOYSA-N dialuminum;calcium;disilicate Chemical compound [Al+3].[Al+3].[Ca+2].[O-][Si]([O-])([O-])[O-].[O-][Si]([O-])([O-])[O-] GWWPLLOVYSCJIO-UHFFFAOYSA-N 0.000 claims description 4
- 238000005098 hot rolling Methods 0.000 claims description 4
- 239000004571 lime Substances 0.000 claims description 4
- 229910052882 wollastonite Inorganic materials 0.000 claims description 4
- 239000010456 wollastonite Substances 0.000 claims description 4
- 229910001678 gehlenite Inorganic materials 0.000 claims description 3
- 238000010438 heat treatment Methods 0.000 claims description 3
- 238000001953 recrystallisation Methods 0.000 claims description 3
- 230000004048 modification Effects 0.000 claims description 2
- 238000012986 modification Methods 0.000 claims description 2
- 239000011651 chromium Substances 0.000 description 17
- 230000007797 corrosion Effects 0.000 description 14
- 238000005260 corrosion Methods 0.000 description 14
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 14
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 10
- 229910052799 carbon Inorganic materials 0.000 description 10
- 239000011572 manganese Substances 0.000 description 10
- 239000010955 niobium Substances 0.000 description 10
- 239000010936 titanium Substances 0.000 description 10
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 9
- 239000010949 copper Substances 0.000 description 9
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 8
- 239000011593 sulfur Substances 0.000 description 8
- 229910052804 chromium Inorganic materials 0.000 description 7
- 230000015572 biosynthetic process Effects 0.000 description 5
- 238000003754 machining Methods 0.000 description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- 150000001247 metal acetylides Chemical class 0.000 description 4
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 3
- 229910052759 nickel Inorganic materials 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 238000005096 rolling process Methods 0.000 description 3
- 229910052710 silicon Inorganic materials 0.000 description 3
- 239000010703 silicon Substances 0.000 description 3
- 229910000859 α-Fe Inorganic materials 0.000 description 3
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 2
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 229910001566 austenite Inorganic materials 0.000 description 2
- 238000005520 cutting process Methods 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 229910000734 martensite Inorganic materials 0.000 description 2
- 229910052750 molybdenum Inorganic materials 0.000 description 2
- 239000011733 molybdenum Substances 0.000 description 2
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical group [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 description 2
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- BUGBHKTXTAQXES-UHFFFAOYSA-N Selenium Chemical compound [Se] BUGBHKTXTAQXES-UHFFFAOYSA-N 0.000 description 1
- 229910004534 SiMn Inorganic materials 0.000 description 1
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 1
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 1
- 240000008042 Zea mays Species 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 230000002051 biphasic effect Effects 0.000 description 1
- 235000020303 café frappé Nutrition 0.000 description 1
- 230000000295 complement effect Effects 0.000 description 1
- 238000012937 correction Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005553 drilling Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000012634 fragment Substances 0.000 description 1
- 230000004927 fusion Effects 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 229910052711 selenium Inorganic materials 0.000 description 1
- 239000011669 selenium Substances 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 235000011149 sulphuric acid Nutrition 0.000 description 1
- 238000004381 surface treatment Methods 0.000 description 1
- 229910052714 tellurium Inorganic materials 0.000 description 1
- PORWMNRCUJJQNO-UHFFFAOYSA-N tellurium atom Chemical compound [Te] PORWMNRCUJJQNO-UHFFFAOYSA-N 0.000 description 1
- 238000012549 training Methods 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 230000002747 voluntary effect Effects 0.000 description 1
- 238000005491 wire drawing Methods 0.000 description 1
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
- C22C38/34—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of 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
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/22—Ferrous alloys, e.g. steel alloys containing chromium with molybdenum or tungsten
-
- 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
- C21D8/12—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties
-
- 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
- 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
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/005—Ferrite
-
- 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
- C21D6/00—Heat treatment of ferrous alloys
- C21D6/008—Heat treatment of ferrous alloys containing Si
-
- 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
- C21D8/06—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires
- C21D8/065—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires of ferrous alloys
Definitions
- the present invention relates to a usable ferritic stainless steel for ferromagnetic parts.
- Ferritic stainless steels are characterized by their composition determined, the ferritic structure being ensured in particular, after rolling and cooling the composition by annealing heat treatment conferring on them said structure.
- the structure of the steel can be biphasic, ferritic and austenitic. If the cooling is, for example energetic, the final structure is ferritic and martensitic. If he is slower, the austenite is broken down partly into ferrite and carbides, but with a carbide content richer than the surrounding matrix, the austenite having hot solubilized more carbon than ferrite. In both cases, a income or annealing must therefore be practiced on hot-rolled steels and cooled to generate a completely ferritic structure. Income can be at a temperature of about 820 ° C lower than the Ac1 temperature of alpha ⁇ gamma transition, which causes a precipitation of carbides.
- ferritic structure In the field of ferritic steels for one application using magnetic properties, the ferritic structure is obtained by limiting the amount of carbides, this is why stainless steels ferritics, developed in this area, have a carbon content less than 0.02%.
- the present invention aims to present a stainless steel of ferritic structure usable for magnetic parts having high magnetic properties and having good properties of implementation in terms of cold stamping and good machinability properties.
- the invention also relates to a method for producing a steel characterized in that the weight composition is subjected, after hot rolling and cooling, annealing heat treatment then to a section modification of the drawing or drawing type.
- Drawn or drawn steel may be subsequently annealed complementary recrystallization to perfect the magnetic properties of the room.
- certain elements contained in the composition of a steel favor the appearance of the ferritic phase of centered cubic structure.
- These elements are called alpha-genes. Among these include chromium and molybdenum.
- Other elements said gamma-genes promote the appearance of the gamma-austenitic phase of cubic structure with centered faces.
- These elements include nickel as well than carbon and nitrogen. It is therefore necessary to reduce the content of these elements and it is for these reasons that the steel according to the invention comprises in its composition less than 0.030% of carbon, less than 0.5% of nickel, less than 0.030% nitrogen.
- Carbon is bad for striking, corrosion and machinability.
- precipitates must be reduced because they constitute obstacles to movements of the walls of Blocks.
- nickel, manganese, copper in the composition due to the industrial development of steel are only residual elements that we seek to reduce and even to eliminate.
- Titanium and / or niobium form compounds whose carbide titanium and / or niobium, which avoids the formation of carbides and nitrides chromium. They favor, therefore, the resistance to corrosion and in particular the holding corrosion of welds.
- Sulfur is limited to optimize the behavior of steel in the field of cold stamping and to optimize magnetic properties.
- Silicon is needed to increase the resistivity of steel in order to reduce eddy currents, and is favorable for corrosion resistance.
- the steels according to the invention may also preferably contain from 0.2% to 3% molybdenum, an element that improves the resistance to corrosion and promotes formation of ferrite.
- ferritic stainless steels pose problems of machinability.
- ferritic steels a big drawback of ferritic steels is the bad conformation of the chip. They produce long, entangled chips that are very difficult to fragment. This disadvantage can become very penalizing in machining modes where the chip is confined, for example in deep drilling, bucking.
- a solution to overcome the problems of machining steels ferritics is to introduce sulfur into their composition or elements type lead, tellurium, selenium that adversely affect the mechanical properties of cold deformation of corrosion resistance, or the properties magnetic.
- Said ferritic steels usually contain Hard inclusions of chromite type (Cr Mn, AI Ti) O, alumina (AIMg) O, silicate (SiMn) O, abrasive for cutting tools.
- the ferritic stainless steel further contains in its composition by weight more than 10 -4 % calcium and more than 70 10 -4 % oxygen.
- the controlled and voluntary introduction of calcium and oxygen favors in ferritic steel the formation of malleable oxides of the lime silicoaluminates type, the malleable oxides being preferably selected from the region of the triple anorthite point, gehlenite, pseudo-wollastonite, of the ternary Al 2 O 3 diagram; SiO 2 ; CaO.
- a steel of ferritic structure according to the invention does not containing no or very little sulfur, has a machining ensuring its use in industrial turning, while presenting increased resistance to corrosion.
- malleable oxides are likely to deform in the direction of rolling, while the hard oxides they replace remain in grain shape.
- the inclusions chosen according to the invention substantially reduce the breakage rate of drawn wire.
- Ferritic steel, according to the invention comprising malleable inclusions, can be polished with much greater ease for obtaining a state of polished surface improved.
- the steel is made by electrical fusion and then poured continuously for to form blooms.
- the blooms are then subjected to hot rolling for forming, for example wire rod or bars.
- the steel is subjected to a supplementary annealing of recrystallization for restore and perfect the magnetic properties.
- the steels according to the invention have better magnetic characteristics than the reference steels, as shown in Table 2 below.
- Steel Hc (A / m) Coercive field Steel 1 109 Steel 2 115 Ref A 184 Ref B 177
- Steel 2 behaves very well in the field of machining bar turning, despite a limited sulfur content. This is explained by the presence of calcium and oxygen.
- Steel 1 has a very good ability to cold stamp, because of of its low sulfur content. On previously struck coins, the finishing machining by turning is carried out correctly, without particular problem.
- the steel according to the invention can be used particularly for the manufacture ferromagnetic parts such as, for example, parts of solenoid valves, injector for gasoline direct injection system, closures centralized door in the automotive field or any application requiring parts of the magnetic core type or inductor. Under the sheet form, it can be used in current transformers or magnetic shielding.
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Manufacturing & Machinery (AREA)
- Electromagnetism (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Soft Magnetic Materials (AREA)
- Heat Treatment Of Steel (AREA)
- Hard Magnetic Materials (AREA)
- Compounds Of Iron (AREA)
- Heat Treatment Of Strip Materials And Filament Materials (AREA)
Abstract
Description
La présente invention concerne un acier inoxydable ferritique utilisable pour des pièces ferromagnétiques.The present invention relates to a usable ferritic stainless steel for ferromagnetic parts.
Les aciers inoxydables ferritiques se caractérisent par une composition déterminée, la structure ferritique étant notamment assurée, après laminage et refroidissement de la composition, par un traitement thermique de recuit leur conférant ladite structure.Ferritic stainless steels are characterized by their composition determined, the ferritic structure being ensured in particular, after rolling and cooling the composition by annealing heat treatment conferring on them said structure.
Parmi les grandes familles d'aciers inoxydables ferritiques, définies notamment en fonction de leur teneur en chrome et en carbone, nous citons :
- les aciers inoxydables ferritiques pouvant contenir jusqu'à 0,17% de carbone. Ces aciers, après le refroidissement qui suit leur élaboration, ont une structure biphasée austéno-ferritique. Ils peuvent cependant être transformés en aciers inoxydables ferritiques après recuit malgré une teneur en carbone relativement élevée.
- les aciers inoxydables ferritiques dont la teneur en chrome est de l'ordre de 11 ou 12 %. Ils sont assez proches des aciers martensitiques contenant 12 % de chrome, mais différents par leur teneur en carbone qui est relativement faible.
- ferritic stainless steels up to 0.17% carbon. These steels, after cooling after their development, have a two-phase austenitic-ferritic structure. However, they can be converted into ferritic stainless steels after annealing despite a relatively high carbon content.
- ferritic stainless steels whose chromium content is of the order of 11 or 12%. They are quite close to martensitic steels containing 12% of chromium, but different in their carbon content which is relatively low.
Lors du laminage des aciers à chaud, la structure de l'acier peut être biphasée, ferritique et austénitique. Si le refroidissement est, par exemple énergique, la structure finale est ferritique et martensitique. S'il est plus lent, l'austénite se décompose partiellement en ferrite et carbures, mais avec une teneur en carbure plus riche que la matrice environnante, l'austénite ayant solubilisé à chaud plus de carbone que la ferrite. Dans les deux cas, un revenu ou recuit doit donc être pratiqué sur les aciers laminés à chaud et refroidis pour générer une structure totalement ferritique. Le revenu peut se faire à une température d'environ 820°C inférieure à la température Ac1 de transition alpha → gamma, ce qui engendre une précipitation de carbures.When rolling hot steels, the structure of the steel can be biphasic, ferritic and austenitic. If the cooling is, for example energetic, the final structure is ferritic and martensitic. If he is slower, the austenite is broken down partly into ferrite and carbides, but with a carbide content richer than the surrounding matrix, the austenite having hot solubilized more carbon than ferrite. In both cases, a income or annealing must therefore be practiced on hot-rolled steels and cooled to generate a completely ferritic structure. Income can be at a temperature of about 820 ° C lower than the Ac1 temperature of alpha → gamma transition, which causes a precipitation of carbides.
Dans le domaine des aciers ferritiques destinés à une application utilisant des propriétés magnétiques, la structure ferritique est obtenue en limitant la quantité de carbures, c'est pour cela que les aciers inoxydables ferritiques, développés dans ce domaine, ont une teneur en carbone inférieure 0,02%.In the field of ferritic steels for one application using magnetic properties, the ferritic structure is obtained by limiting the amount of carbides, this is why stainless steels ferritics, developed in this area, have a carbon content less than 0.02%.
Il est connu des aciers utilisables pour leurs propriétés magnétiques comme par exemple dans le document US 5 769 974 qui décrit un procédé de fabrication d'un acier ferritique résistant à la corrosion et pouvant réduire la valeur du champ coercitif dudit acier. L'acier utilisé dans le procédé est un acier du type re sulfuré. Le soufre réduit les propriétés de déformation à froid. L'acier obtenu par le procédé est donc difficilement utilisable pour la réalisation de pièces frappées à froid.Steels that can be used for their magnetic properties are known as for example in US 5,769,974 which describes a process ferritic steel that is resistant to corrosion and can reduce value of the coercive field of said steel. The steel used in the process is a steel of the sulfide type. Sulfur reduces cold deformation properties. The steel obtained by the process is therefore difficult to use for realization of cold-struck pieces.
Il est connu aussi le brevet US 5 091 024 dans lequel il est présenté des articles magnétiques résistant à la corrosion formée d'un alliage consistant essentiellement en une composition à faible teneur en carbone et faible teneur en silicium, c'est-à-dire respectivement inférieures à 0,03% et 0,5%. Or, dans le domaine magnétique, il est important que l'acier contienne une forte teneur en silicium pour augmenter la résistivité du matériau et réduire les courants de Foucault.It is also known from US Pat. No. 5,091,024 in which it is presented corrosion-resistant magnetic articles formed of a alloy consisting of basically in a low carbon composition and low silicon content, that is to say respectively less than 0.03% and 0.5%. However, in the magnetic field, it is important for steel to contain a high silicon content to increase the resistivity of the material and reduce eddy currents.
La présente invention a pour but de présenter un acier inoxydable de structure ferritique utilisable pour des pièces magnétiques ayant de hautes propriétés magnétiques et présentant de bonnes propriétés de mise en oeuvre en terme de frappe à froid et de bonnes propriétés d'usinabilité.The present invention aims to present a stainless steel of ferritic structure usable for magnetic parts having high magnetic properties and having good properties of implementation in terms of cold stamping and good machinability properties.
L'invention a pour objet un acier inoxydable ferritique utilisable pour des
pièces ferromagnétiques qui se caractérise en ce qu'il comprend dans sa
composition pondérale :
Les autres caractéristiques de l'invention sont :
- le rapport entre la teneur en calcium et en oxygène Ca/O étant
0,2 ≤ Ca/O ≤ 0,6. - l'acier contient des inclusions de silico-aluminale de chaux de type anorthite et/ou pseudo-wollastonite et/ou gehlénite.
- de préférence l'acier-comprend dans sa composition pondérale : 1
- 0% < C 0.015%
- 1% ≤ Si ≤ 3%
- 0 ≤ Mn ≤ 0,4%
- 10% ≤ Cr ≤ 13%
- 0% < Ni ≤ 0,2%
- 0,2% ≤ Mo ≤ 2%
- N ≤ 0,015%
- Cu ≤ 0,2%
- Ti ≤ 0,2%
- Nb ≤ 1%
- Ca ≥ 30 10-4%
- O ≥ 70 10-4%
- S ≤ 0,003%
- P ≤ 0,030% le reste étant du fer et les impuretés inévitables à l'élaboration de l'acier.
- de préférence l'acier comprend dans sa composition pondérale :
- 0% < C ≤ 0.015%
- 1% ≤ Si ≤ 3%
- 0 ≤ Mn ≤ 0,4%
- 10% ≤ Cr ≤ 13%
- 0% < Ni ≤ 0,2%
- 0,2% ≤ Mo ≤ 2%
- N ≤ 0,015%
- Cu ≤ 0,2%
- Ti ≤ 0,2%
- Nb ≤ 1%
- Ca ≥ 30 10-4%
- O ≥ 70 10-4%
- 0,015 ≤ S ≤ 0,03%
- P ≤ 0,030% le reste étant du fer et les impuretés inévitables à l'élaboration de l'acier.
- the ratio between the calcium and oxygen content Ca / O being
0.2 ≤ Ca / O ≤ 0.6. - the steel contains silicoaluminium inclusions of lime type anorthite and / or pseudo-wollastonite and / or gehlenite.
- preferably the steel-comprises in its weight composition: 1
- 0% <C 0.015%
- 1% ≤ If ≤ 3%
- 0 ≤ Mn ≤ 0.4%
- 10% ≤ Cr ≤ 13%
- 0% <Ni ≤ 0.2%
- 0.2% ≤ Mo ≤ 2%
- N ≤ 0.015%
- Cu ≤ 0.2%
- Ti ≤ 0.2%
- Nb ≤ 1%
- Ca ≥ 30 10 -4 %
- O ≥ 70 10 -4 %
- S ≤ 0.003%
- P ≤ 0.030% the rest being iron and the inevitable impurities in the making of steel.
- preferably the steel comprises in its weight composition:
- 0% <C ≤ 0.015%
- 1% ≤ If ≤ 3%
- 0 ≤ Mn ≤ 0.4%
- 10% ≤ Cr ≤ 13%
- 0% <Ni ≤ 0.2%
- 0.2% ≤ Mo ≤ 2%
- N ≤ 0.015%
- Cu ≤ 0.2%
- Ti ≤ 0.2%
- Nb ≤ 1%
- Ca ≥ 30 10 -4 %
- O ≥ 70 10 -4 %
- 0.015 ≤ S ≤ 0.03%
- P ≤ 0.030% the rest being iron and the inevitable impurities in the making of steel.
L'invention concerne également un procédé d'élaboration d'un acier ferritique caractérisé en ce que la composition pondérale est soumise, après laminage à chaud et refroidissement, à un traitement thermique de recuit puis à une modification de section du type tréfilage ou étirage.The invention also relates to a method for producing a steel characterized in that the weight composition is subjected, after hot rolling and cooling, annealing heat treatment then to a section modification of the drawing or drawing type.
L'acier tréfilé ou étiré peut être ultérieurement soumis à un recuit complémentaire de recristallisation pour parfaire les propriétés magnétiques de la pièce.Drawn or drawn steel may be subsequently annealed complementary recrystallization to perfect the magnetic properties of the room.
La description qui suit à titre d'exemple non limitatif, fera bien comprendre l'invention.The following description by way of example non-limiting, will make clear the invention.
L'invention concerne un acier de composition générale suivante :
Du point de vue métallurgique, certains éléments contenus dans la composition d'un acier favorisent l'apparition de la phase ferritique de structure cubique centrée. Ces éléments sont dits alpha-gènes. Parmi ceux-ci figurent notamment le chrome et le molybdène. D'autres éléments dits gamma-gènes favorisent l'apparition de la phase gamma-austénitique de structure cubique à faces centrées. Parmi ces éléments figurent le nickel ainsi que le carbone et l'azote. Il est donc nécessaire de réduire la teneur de ces éléments et c'est pour ces raisons que l'acier selon l'invention comporte dans sa composition moins de 0,030% de carbone, moins de 0,5% de nickel, moins de 0,030% d'azote.From a metallurgical point of view, certain elements contained in the composition of a steel favor the appearance of the ferritic phase of centered cubic structure. These elements are called alpha-genes. Among these include chromium and molybdenum. Other elements said gamma-genes promote the appearance of the gamma-austenitic phase of cubic structure with centered faces. These elements include nickel as well than carbon and nitrogen. It is therefore necessary to reduce the content of these elements and it is for these reasons that the steel according to the invention comprises in its composition less than 0.030% of carbon, less than 0.5% of nickel, less than 0.030% nitrogen.
Le carbone est néfaste pour la frappe, la corrosion et l'usinabilité. De manière générale, dans le domaine des propriétés magnétiques, les précipités doivent être réduits car ils constituent des obstacles aux mouvements des parois de Blocks.Carbon is bad for striking, corrosion and machinability. Of Generally speaking, in the field of magnetic properties, precipitates must be reduced because they constitute obstacles to movements of the walls of Blocks.
Concernant les autres éléments de la composition, le nickel, le manganèse, le cuivre dans la composition, due à l'élaboration industrielle de l'acier ne sont que des éléments résiduels qu'on cherche à réduire et même à éliminer.As regards the other elements of the composition, nickel, manganese, copper in the composition, due to the industrial development of steel are only residual elements that we seek to reduce and even to eliminate.
Le titane et ou le niobium forment des composés dont le carbure de titane et ou de niobium, ce qui évite la formation de carbures et de nitrures de chrome. Ils favorisent, de ce fait la tenue à la corrosion et notamment la tenue en corrosion des soudures.Titanium and / or niobium form compounds whose carbide titanium and / or niobium, which avoids the formation of carbides and nitrides chromium. They favor, therefore, the resistance to corrosion and in particular the holding corrosion of welds.
Le soufre est limité de façon à optimiser le comportement de l'acier dans le domaine de la frappe à froid et à optimiser les propriétés magnétiques.Sulfur is limited to optimize the behavior of steel in the field of cold stamping and to optimize magnetic properties.
Le silicium est nécessaire pour augmenter la résistivité de l'acier afin de réduire les courants de Foucault, et est favorable pour la tenue à la corrosion.Silicon is needed to increase the resistivity of steel in order to reduce eddy currents, and is favorable for corrosion resistance.
Les aciers selon l'invention peuvent également contenir de préférence de 0,2% à 3% de molybdène, élément améliorant la résistance à la corrosion et favorisant la formation de la ferrite.The steels according to the invention may also preferably contain from 0.2% to 3% molybdenum, an element that improves the resistance to corrosion and promotes formation of ferrite.
Dans le domaine de leur utilisation, les aciers inoxydables ferritiques posent des problèmes d'usinabilité.In the field of their use, ferritic stainless steels pose problems of machinability.
En effet, un gros inconvénient des aciers ferritiques est la mauvaise conformation du copeau. Ils produisent des copeaux longs et enchevêtrés, qui sont très difficiles à fragmenter. Cet inconvénient peut devenir très pénalisant dans des modes d'usinages où le copeau est confiné, comme par exemple dans le perçage profond, le tronçonnage.Indeed, a big drawback of ferritic steels is the bad conformation of the chip. They produce long, entangled chips that are very difficult to fragment. This disadvantage can become very penalizing in machining modes where the chip is confined, for example in deep drilling, bucking.
Une solution apportée pour pallier les problèmes d'usinage des aciers ferritiques est d'introduire du soufre dans leur composition ou des éléments du type plomb, tellure, sélénium qui nuisent soit aux propriétés mécaniques de déformation à froid de résistance à la corrosion, soit aux propriétés magnétiques. Lesdits aciers ferritiques contiennent habituellement des inclusions dures de type chromite (Cr Mn, AI Ti)O, alumine (AIMg)O, silicate (SiMn)O, abrasives pour les outils de coupe.A solution to overcome the problems of machining steels ferritics is to introduce sulfur into their composition or elements type lead, tellurium, selenium that adversely affect the mechanical properties of cold deformation of corrosion resistance, or the properties magnetic. Said ferritic steels usually contain Hard inclusions of chromite type (Cr Mn, AI Ti) O, alumina (AIMg) O, silicate (SiMn) O, abrasive for cutting tools.
Selon l'invention, l'acier inoxydable ferritique contient en outre dans sa composition en poids plus de 30 10-4% calcium et plus de 70 10-4% d'oxygène.According to the invention, the ferritic stainless steel further contains in its composition by weight more than 10 -4 % calcium and more than 70 10 -4 % oxygen.
L'introduction de façon contrôlée et volontaire de calcium et d'oxygène vérifiant la relation 0,2 ≤ Ca/O ≤ 0,6 favorise dans l'acier ferritique, la formation d'oxydes malléables du type silicoaluminates de chaux, les oxydes malléables étant choisis de préférence dans la zone du point triple anorthite, gehlenite, pseudo-wollastonite, du diagramme ternaire Al2O3 ; SiO2 ; CaO. The controlled and voluntary introduction of calcium and oxygen, verifying the 0.2 ≤ Ca / O 0.6 ratio, favors in ferritic steel the formation of malleable oxides of the lime silicoaluminates type, the malleable oxides being preferably selected from the region of the triple anorthite point, gehlenite, pseudo-wollastonite, of the ternary Al 2 O 3 diagram; SiO 2 ; CaO.
La présence de calcium et oxygène réduit de façon conséquente la formation des inclusions dures et abrasives de type chromite, alumine, silicate. Par contre, la formation des inclusions de silicoaluminates de chaux favorise le fractionnement des copeaux et améliore la durée de vie des outils de coupe.The presence of calcium and oxygen significantly reduces the formation of hard and abrasive inclusions of the chromite, alumina type, silicate. On the other hand, the formation of inclusions of silicoaluminates of lime promotes chip splitting and improves tool life cutting.
On a constaté que l'introduction d'oxydes à base de calcium dans un acier de structure ferritique, en remplacement des oxydes durs existants, ne modifie que très peu les autres caractéristiques de l'acier ferritique dans le domaine de la déformation à chaud, de la frappe à froid, la résistance à la corrosion et propriétés magnétiques.It has been found that the introduction of calcium-based oxides into a Ferritic structure steel, replacing the existing hard oxides, does not alters the other characteristics of ferritic steel in the field of hot deformation, cold stamping, resistance to corrosion and magnetic properties.
Il s'est avéré qu'un acier de structure ferritique selon l'invention, ne contenant pas ou très peu de soufre, a un usinage assurant son utilisation industrielle en décolletage, tout en présentant une résistance accrue à la corrosion.It has been found that a steel of ferritic structure according to the invention does not containing no or very little sulfur, has a machining ensuring its use in industrial turning, while presenting increased resistance to corrosion.
La présence d'oxydes dits malléables dans un acier ferritique, entraíne des avantages dans le domaine du tréfilage et étirage.The presence of so-called malleable oxides in a ferritic steel, leads to advantages in the field of drawing and drawing.
En effet, les oxydes malléables sont susceptibles de se déformer dans le sens du laminage, alors que les oxydes durs qu'ils remplacent restent en forme de grains.Indeed, malleable oxides are likely to deform in the direction of rolling, while the hard oxides they replace remain in grain shape.
Dans le domaine du tréfilage de fils d'acier ferritique de faible diamètre, les inclusions choisies selon l'invention réduisent de manière conséquente le taux de casse du fil tréfilé.In the field of drawing ferritic steel wire of small diameter, the inclusions chosen according to the invention substantially reduce the breakage rate of drawn wire.
Dans un autre domaine d'application, par exemple dans des opérations de polissage, les inclusions dures s'incrustent dans l'acier ferritique et provoquent des sillons en surface.In another field of application, for example in operations hard inclusions become encrusted in ferritic steel and cause furrows on the surface.
L'acier ferritique, selon l'invention comportant des inclusions malléables, peut être poli avec beaucoup plus d'aisance pour l'obtention d'un état de surface poli amélioré.Ferritic steel, according to the invention comprising malleable inclusions, can be polished with much greater ease for obtaining a state of polished surface improved.
L'acier est élaboré par fusion électrique puis coulé en continu pour former des blooms.The steel is made by electrical fusion and then poured continuously for to form blooms.
Les blooms sont ensuite soumis à un laminage à chaud pour la formation, par exemple de fil machine ou de barres. The blooms are then subjected to hot rolling for forming, for example wire rod or bars.
Un recuit est nécessaire pour assurer les opérations de transformation à froid du produit par exemple tréfilage et étirage.An annealing is necessary to ensure the transformation operations to cold product eg wire drawing and drawing.
L'acier est soumis à un recuit complémentaire de recristallisation pour restaurer et parfaire les propriétés magnétiques.The steel is subjected to a supplementary annealing of recrystallization for restore and perfect the magnetic properties.
Suit alors un traitement de surface.Then follows a surface treatment.
Dans un exemple d'application, il a été élaboré deux aciers selon
l'invention référencés acier 1 et acier 2, ainsi que deux aciers de référence A
et B dont les compositions sont représentées dans le tableau 1 suivant :
Ces aciers ont été transformés en barres de diamètre 10 mm selon le procédé suivant :
- un laminage à chaud de rond de 11 mm,
- un recuit,
- un étirage en diamètre de 10 mm,
- un recuit final,
- un dressage et une rectification,
- hot rolling of 11 mm round,
- an annealing,
- drawing in diameter of 10 mm,
- a final annealing,
- a training and a correction,
Les aciers selon l'invention ont de meilleures caractéristiques
magnétiques que les aciers de référence, comme présenté sur le tableau 2
suivant.
Ces caractéristiques sont dues à une faible teneur en éléments d'addition en particulier une teneur en chrome d'environ 12%.These characteristics are due to a low content of elements in particular a chromium content of about 12%.
L'acier 2 se comporte très bien dans le domaine de l'usinage par décolletage, malgré une teneur limitée en soufre. Cela s'explique par la présence de calcium et d'oxygène.Steel 2 behaves very well in the field of machining bar turning, despite a limited sulfur content. This is explained by the presence of calcium and oxygen.
L'acier 1 présente une très bonne aptitude à la frappe à froid, en raison de sa faible teneur en soufre. Sur des pièces préalablement frappées, l'usinage de finition par décolletage s'effectue de manière correcte, sans problème particulier.Steel 1 has a very good ability to cold stamp, because of of its low sulfur content. On previously struck coins, the finishing machining by turning is carried out correctly, without particular problem.
Les aciers 1 et 2 se comportent très bien dans le domaine de la
corrosion, malgré leur faible teneur en chrome, comme on peut le remarquer
sur le tableau 3 suivant. Cela est du pour l'acier 1 à une faible teneur en
soufre et pour l'acier 2 à une teneur limitée en soufre associé à une faible
teneur en manganèse.
L'acier selon l'invention est utilisable particulièrement pour la fabrication de pièce ferromagnétique comme par exemple, des pièces d'électrovannes, d'injecteur pour système d'injection directe d'essence, de fermetures centralisées de porte dans le domaine de l'automobile ou toute application nécessitant des pièces du type noyau magnétique ou inducteur. Sous la forme de feuille, il peut être utilisé dans des transformateurs de courant ou des blindages magnétiques.The steel according to the invention can be used particularly for the manufacture ferromagnetic parts such as, for example, parts of solenoid valves, injector for gasoline direct injection system, closures centralized door in the automotive field or any application requiring parts of the magnetic core type or inductor. Under the sheet form, it can be used in current transformers or magnetic shielding.
Claims (7)
- Ferritic stainless steel which can be used for ferromagnetic parts, characterised in that its composition by weight is as follows:0% < C ≤ 0.030%1% ≤ Si ≤ 3%0% < Mn ≤ 0.5%10% ≤ Cr ≤ 13%0% < Ni ≤ 0.5%0% < Mo ≤ 3%N ≤ 0.030%Cu ≤ 0.5%Ti ≤ 0.5%Nb ≤ 1%Ca > 30 10-4%O > 70 10-4%S ≤ 0.030%P ≤ 0.030%
- Steel according to claim 1, characterised in that the ratio between the calcium content and the oxygen content Ca/O is:0.2 ≤ Ca/O ≤ 0.6
- Steel according to claim 1, characterised in that it contains silico-aluminate of lime inclusions of the anorthite and/or pseudo-wollastonite and/or gehlenite type.
- Steel according to claim 1, characterised in that its composition by weight is as follows:C ≤ 0. 012%1% ≤ Si ≤ 3%0% ≤ Mn ≤ 0.4%10% ≤ Cr ≤ 13%0% ≤ Ni ≤ 0.2%0.2% ≤ Mo ≤ 2%N ≤ 0.015%Cu ≤ 0.2%Ti ≤ 0.2%Nb ≤ 1%Ca ≤ 30 10-4%O ≥ 70 10-4%S ≤ 0.003%P ≤ 0.030%
- Steel according to claim 1, characterised in that its composition by weight is as follows:0% < C ≤ 0.012%1% ≤ Si ≤ 3%0% ≤ Mn ≤ 0.4%10% ≤ Cr ≤ 13%0% < Ni ≤ 0.2%0.2% ≤ Mo ≤ 2%N ≤ 0.015%Cu ≤ 0.2%Ti ≤ 0.2%Nb ≤ 1%Ca ≥ 30 10-4%O ≥ 70 10-4 %0.015 ≥ S ≤ 0.03%P ≤ 0.030%
- Method of producing a ferritic steel according to one of claims 1 to 5, characterised in that, after hot rolling and cooling, the steel is subjected to an annealing heat treatment then to a modification of cross-section by means of drawing or stretch-forming.
- Method according to claim 6, characterised in that the drawn or stretch-formed steel can later be subjected to additional recrystallisation annealing to perfect the magnetic properties of the part.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
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FR0009152A FR2811683B1 (en) | 2000-07-12 | 2000-07-12 | FERRITIC STAINLESS STEEL FOR USE IN FERROMAGNETIC PARTS |
FR0009152 | 2000-12-07 | ||
PCT/FR2001/002214 WO2002004689A1 (en) | 2000-07-12 | 2001-07-10 | Ferritic stainless steel for ferromagnetic parts |
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EP1299569A1 EP1299569A1 (en) | 2003-04-09 |
EP1299569B1 true EP1299569B1 (en) | 2004-06-16 |
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ID=8852438
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US (2) | US6821358B2 (en) |
EP (1) | EP1299569B1 (en) |
JP (1) | JP2004502867A (en) |
KR (1) | KR20020029408A (en) |
CN (1) | CN1202275C (en) |
AT (1) | ATE269426T1 (en) |
AU (1) | AU7263501A (en) |
BR (1) | BR0106950A (en) |
CA (1) | CA2384754A1 (en) |
DE (1) | DE60103899T2 (en) |
FR (1) | FR2811683B1 (en) |
MX (1) | MXPA02002629A (en) |
WO (1) | WO2002004689A1 (en) |
ZA (1) | ZA200201897B (en) |
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US9943847B2 (en) | 2002-04-17 | 2018-04-17 | Cytonome/St, Llc | Microfluidic system including a bubble valve for regulating fluid flow through a microchannel |
JP4519543B2 (en) * | 2004-07-01 | 2010-08-04 | 新日鐵住金ステンレス株式会社 | Low cost stainless steel wire having magnetism with excellent corrosion resistance, cold workability and toughness, and method for producing the same |
US9260693B2 (en) | 2004-12-03 | 2016-02-16 | Cytonome/St, Llc | Actuation of parallel microfluidic arrays |
EP2211099A1 (en) * | 2009-01-21 | 2010-07-28 | José Luis Flores Torre | Use of chromium-based stainless steel for manufacturing a domestic use and manual opening magnetic unit actuated by thermocouple or equvalent element |
WO2013072124A1 (en) * | 2011-11-14 | 2013-05-23 | Nv Bekaert Sa | Steel wire for magnetic field absorption |
EP2886890B1 (en) * | 2013-12-18 | 2019-06-26 | Skf Magnetic Mechatronics | Thrust disc, magnetic bearing and apparatus |
DE202014004267U1 (en) * | 2014-05-23 | 2014-07-04 | Few Fahrzeugelektrikwerk Gmbh & Co. Kg | Electrical connection element for fastening, in particular soldering on a glass pane as well as mixed tape braid |
FR3047254B1 (en) * | 2016-02-02 | 2018-02-16 | Vallourec Tubes France | STEEL COMPOSITION WITH IMPROVED ANTI-COKAGE PROPERTIES |
JP6574739B2 (en) * | 2016-07-05 | 2019-09-11 | 秋山精鋼株式会社 | Coercivity adjustment method for ferritic stainless steel bar |
JP6912369B2 (en) * | 2017-12-22 | 2021-08-04 | 日鉄ステンレス株式会社 | Ferritic stainless steel with excellent rust resistance |
KR102279909B1 (en) * | 2019-11-19 | 2021-07-22 | 주식회사 포스코 | Ferritic stainless steel having high magnetic permeability |
ES2897523B2 (en) | 2021-08-10 | 2022-07-18 | Advanced Thermal Devices S L | Cathode based on the material C12A7:e ''electride'' for thermionic emission of electrons and procedure for its use |
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JPS55138057A (en) * | 1979-04-12 | 1980-10-28 | Daido Steel Co Ltd | Stainless steel for cold header |
JP3312401B2 (en) * | 1992-11-04 | 2002-08-05 | 大同特殊鋼株式会社 | Calcium free-cutting stainless steel |
FR2706489B1 (en) * | 1993-06-14 | 1995-09-01 | Ugine Savoie Sa | Martensitic stainless steel with improved machinability. |
FR2720410B1 (en) * | 1994-05-31 | 1996-06-28 | Ugine Savoie Sa | Ferritic stainless steel with improved machinability. |
JP3116156B2 (en) * | 1994-06-16 | 2000-12-11 | 新日本製鐵株式会社 | Method for producing steel pipe with excellent corrosion resistance and weldability |
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 |
FR2740783B1 (en) * | 1995-11-03 | 1998-03-06 | Ugine Savoie Sa | FERRITIC STAINLESS STEEL USABLE FOR THE PRODUCTION OF STEEL WOOL |
US5769974A (en) * | 1997-02-03 | 1998-06-23 | Crs Holdings, Inc. | Process for improving magnetic performance in a free-machining ferritic stainless steel |
JP3589036B2 (en) * | 1997-08-05 | 2004-11-17 | Jfeスチール株式会社 | Ferritic stainless steel sheet excellent in deep drawability and ridging resistance and method for producing the same |
JP3508520B2 (en) * | 1997-12-05 | 2004-03-22 | Jfeスチール株式会社 | Cr-containing ferritic steel with excellent high-temperature fatigue properties for welds |
TW496903B (en) * | 1997-12-19 | 2002-08-01 | Armco Inc | Non-ridging ferritic chromium alloyed steel |
JP3941267B2 (en) * | 1998-11-02 | 2007-07-04 | Jfeスチール株式会社 | High corrosion-resistant chromium-containing steel with excellent oxidation resistance and intergranular corrosion resistance |
-
2000
- 2000-07-12 FR FR0009152A patent/FR2811683B1/en not_active Expired - Fee Related
-
2001
- 2001-07-10 DE DE60103899T patent/DE60103899T2/en not_active Expired - Lifetime
- 2001-07-10 CA CA002384754A patent/CA2384754A1/en not_active Abandoned
- 2001-07-10 AU AU72635/01A patent/AU7263501A/en not_active Abandoned
- 2001-07-10 EP EP01951783A patent/EP1299569B1/en not_active Expired - Lifetime
- 2001-07-10 MX MXPA02002629A patent/MXPA02002629A/en active IP Right Grant
- 2001-07-10 BR BR0106950-0A patent/BR0106950A/en not_active Application Discontinuation
- 2001-07-10 AT AT01951783T patent/ATE269426T1/en not_active IP Right Cessation
- 2001-07-10 KR KR1020027003223A patent/KR20020029408A/en not_active Application Discontinuation
- 2001-07-10 WO PCT/FR2001/002214 patent/WO2002004689A1/en active IP Right Grant
- 2001-07-10 CN CNB018020100A patent/CN1202275C/en not_active Expired - Lifetime
- 2001-07-10 JP JP2002509542A patent/JP2004502867A/en not_active Withdrawn
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2002
- 2002-03-07 ZA ZA200201897A patent/ZA200201897B/en unknown
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- 2004-10-20 US US10/968,192 patent/US20050279425A1/en not_active Abandoned
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DE60103899T2 (en) | 2005-06-30 |
FR2811683A1 (en) | 2002-01-18 |
CN1386144A (en) | 2002-12-18 |
MXPA02002629A (en) | 2002-07-30 |
FR2811683B1 (en) | 2002-08-30 |
JP2004502867A (en) | 2004-01-29 |
US20020129873A1 (en) | 2002-09-19 |
AU7263501A (en) | 2002-01-21 |
WO2002004689A1 (en) | 2002-01-17 |
DE60103899D1 (en) | 2004-07-22 |
EP1299569A1 (en) | 2003-04-09 |
ZA200201897B (en) | 2003-03-07 |
CN1202275C (en) | 2005-05-18 |
KR20020029408A (en) | 2002-04-18 |
ATE269426T1 (en) | 2004-07-15 |
BR0106950A (en) | 2002-05-21 |
US6821358B2 (en) | 2004-11-23 |
CA2384754A1 (en) | 2002-01-17 |
US20050279425A1 (en) | 2005-12-22 |
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