Thermal processing of metal strip and metal strip thus produced |
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IPC classes for russian patent Thermal processing of metal strip and metal strip thus produced (RU 2557032):
      
Method of reinforcement steel manufacturing / 2543045
Method of reinforcement steel manufacturing includes making of steel containing, wt %: carbon 0.78-0.82, manganese 0.70-0.90, silicon 0.20-0.30, sulphur 0.010 maximum, phosphorus 0.025 maximum, chrome 0.20-0.30, nickel 0.10 maximum, copper 0.10 maximum, aluminium 0.005 maximum, boron 0.0010-0.0030, nitrogen 0.008 maximum, titanium 0.005% maximum, iron - rest, at that total content Cr+Mn+Ni+Cu < 1.4 is maintained, and ratio Al/B within range < 1.67. Heat treatment is performed by heating in furnace to 900-940°C with further isothermal hardening for 85-110 s in lead melt at temperature 530-560°C and final cooling with water. Cold drawing of roll is performed with total shrinkage 57-62%.
 Shaped steel wire with high mechanical properties resisting hydrogen attack / 2533573
To ensure required mechanical properties proposed wire is made from steel produced at liquid metal processing that contains the following elements, in wt %: 0,75≤C≤0.95, 0.30≤Mn≤0.85, Cr≤0.4, V≤0.16, Si≤1.40 and preferably >0.15 and not obligatorily not over 0.06 of Al, not over 0.1% of Ni, not over 0.1 of Cu, iron and unavoidable impurities. Said wire is made from hot-rolled 5-30 mm diameter rod and cooled to the room temperature and subjected to thermomechanical processing in two steps: isothermal quenching to get homogeneous perlite microstructure and cold drawing at total reduction of 50-80% to shape it as required. Now, it is subjected to reducing short-term thermal treatment under Acl, preferably, at 410-710°C.
 Steel sheet processing universal line for production of various high-strength steels / 2519458
Invention relates to metal forming. Proposed line comprises unwinding and flushing station, heating station, holding station and delayed cooling station. Hydrogen cooling station and water quenching station are located downstream thereof and in parallel therewith. Note here that downstream of hydrogen cooling station located are reheating station, overageing station, final cooling station, straightening station, finishing station, lubrication station and winding station. Downstream of water quenching station located are acid flushing station and galvanic station. Note also that hot zinc-plating station is arranged downstream of reheating station and connected therewith. Note also that galvanil-plating station is arranged downstream of hot zinc-plating station and connected therewith. Mind that acid flushing station and galvanic stations are separately connected with reheating station via connection channels. Said galvanic station is directly connected via connection channel with unwinding station and flushing station. Water quenching station is connected with delayed cooling station via fixed bypass channel. Reheating station is connected with overageing station via plug-in bypass channel.
Method for obtaining reinforcement wire from high-carbon steel / 2496888
Achievement of the required level of strength properties in the obtained high-strength wire of large diameters from rolled wire with diameter of 15-16 mm due to regulations of temperature-speed conditions of heating and intensive cooling of rolled wire during heat treatment. Besides, temperature of intensive cooling is maintained at the level of 550±10°C, and duration of exposure at rolled wire quenching is determined by the following ratio: T=740/(D*V), seconds, where D - diameter of rolled wire, mm; V- movement speed of rolled wire during intensive cooling, m/s.
 Manufacturing method of high-strength nanostructured steel reinforcement / 2471004
Manufacturing method of high-strength steel reinforcement involves melting of steel of the specified chemical composition, in which total content of Cr+Ni+Cu<0.14 is maintained, and ratio of aluminium to boron (Al/B) is within 10 - 20; heat treatment of hot-rolled rod is performed by heating in the furnace up to 900-940°C with further isothermal hardening during 85-110 seconds in molten lead at temperature of 530-560°C and final water cooling, and drawing of hot-rolled rod is performed with total shrinkage of 57-62%. Invention will allow obtaining metal nanostructure after heat treatment, which consists of ferrite-carbide mixture with interlamellar distance of 80-180 nm and small quantity of structurally free ferrite in the form of islands along grain boundaries. Strength of not less than 1570 N/mm2, yield strength of not less than 1400 N/mm2 and relative breaking elongation of not less than 6% is provided in cold deformed high-strength reinforcement.
 Method and device for continuous formation of bainitic structure in carbon steel, mainly in strip steel / 2449030
Invention refers to metallurgy, and namely to manufacturing procedure of hot-dip-galvanised strip of increased strength, which is intended for manufacture of automobile parts by forming. Austenitisation (3) of carbon steel (1) is performed at temperature exceeding austenitisation temperature; then, steel (1) is added to bath (2) containing hardening agent (21) for cooling to the temperature which is lower than austenitisation temperature; steel (1) is brought to temperature of bainitic conversion and exposed during certain period of time at that temperature; at that, the amount of hardening medium (21) and duration of steel contact with hardening medium (21) is such that in general structure of carbon steel (1) placed in bath (2) containing hardening medium (21) there formed is the specified fraction of bainitic structure; at discharge of carbon steel (1) from bath (2) the residues of hardening medium (21) are removed from its surface by gas action; then, carbon steel (1) is moved through isothermic exposure station (13) which is located after bath and in which there performed is conversion of the rest component parts of carbon steel (1) structure to bainite, which is performed at temperature of bainitic conversion and without deflection of carbon steel (1) at its movement till complete formation in it of bainitic structure, and steel (1) is finally cooled at cooling station (17,18).
 Procedure for quenching long-length metal items / 2437943
Item is heated and tempered at low temperature. Also, the long-length item is continuously transferred on a transporter at rate 3-10 mm/sec. The item passes through a local zone of heating with alternative electro-magnetic field of 8-20 kHz frequency. In the local zone the item is heated to temperature 800-1000°C. Further tempering is performed to temperature 300-200°C. Local intensive cooling with a jet of compressed air facilitates formation of martensite structure of metal, where upon temperature of the item is brought to temperature of environment.
 Method of controlled cooling of hot-rolled strip roll and device for method implementation / 2391417
Invention refers to metallurgy, particularly cooling of hot-rolled strip roll. To reduce structural irregularity of metal, maintain homogeneous physical and mechanical properties along strip length and width, and increase yield, hot-roller strip roll placed horizontally is cooled by pressure difference generation in the roll cavity formed by two hemispheric vessels positioned at the roll ends, with one vessel connected to receiver and another vessel connected to ejector to change underpressure grade. Device for implementation of horizontal roll cooling method includes vessels with coolant, Each vessel is made in the form of hemisphere with drive for horizontal movement against the roll ends and features centering locks. One vessel is connected to receiver by coolant feed pipe, the other vessel is connected by coolant drainage pipe to ejector and cooler to create pressure difference at the roll ends.
 Method of cooling of rails of hot-rolled strip with simultaneous thermal treatment of external coils and facility for its realisation / 2384631
It is implemented cooling of rails in heat-isolated volume, during the process of cooling is isolated by unequal heat currents through bottom and top parts of heat-insulated volume so that heat current through top part, as minimum two times but not more than 5 times more intensive than through bottom. Device implementing cooling method of rolls of hot-rolled strip with simultaneous thermal treatment of external coils, includes stand for installation of rolls and het insulating casing, consisting of bottom and top part, height of which is less than 30% of total height of casing wall, and its coefficient of heat conduction allows value not low than 1.0 Wt/m·K, herewith thermal-conductivity coefficient of bottom part of wall of casing shouldn't be higher than 0.17 Wt/m°K.
 Method of production of steel hard-drawn band / 2369649
Hot rolled flat bar of 2.0-2.8 mm thickness containing, wt %: 0.08-0.15 of carbon, 0.05-0.10 of silicon and 0.4-0.7 of manganese is subject to preliminary annealing in bell-type furnaces with conditioning during 4 h at temperature t1=500°C and with conditioning during 10 h at t2=560°C with total time of heating 20 h, further cold rolling is carried out for finish thickness h=0.5-1.0 mm accepting value of total reduction
 Method to produce textured sheet of electric steel / 2553789
Electric steel sheet roll after cold rolling is exposed to primary recrystallisation annealing, an annealing separator is applied on it, and final annealing is performed. Heating of the roll for the primary recrystallisation annealing is carried out with a speed of at least 80°C/s from 500°C to 700°C in the process of heating, and during heating for final annealing, exposure is carried out from 2 to 100 hours at a temperature from 700°C to 1000°C. Final annealing of the roll is carried out in an annealing furnace, at the same time a heat insulation material is laid onto the upper surface of the stand supporting the roll, concentrically from the external periphery of the stand supporting the roll, and in the area of at least 20% of the radius of the stand supporting the roll.
 Steel plate of hot-stamped product and method of its manufacturing / 2552817
Invention relates to metallurgy, namely to manufacturing of the steel plate used to manufacture hot-stamped products. The plate is made out of steel with the following chemical composition in wt %: from 0.10 to 0.35 C, from 0.01 to 1.0 Si, from 0.3 to 2.3 Mn, from 0.01 to 0.5 Al, maximum 0.03 P, maximum 0.02 S, maximum 0.1 N, Fe and inevitable admixtures - rest. RMS deviation of particle diameters of iron carbide contained in area at distance up to 1/4 of thickness from steel plate surface is below or equal to 0.8 micron.
 Hot-rolled, cold-rolled and cladded steel plate having improved uniform and local ductility at high deformation rate / 2543590
Invention relates to a hot-rolled, cold-rolled and cladded steel plate, which has improved uniform ductility and local ductility at high deformation rate. According to one version of implementation of the invention, a hot-rolled steel plate has a metallographic structure including the main phase from ferrite with an average grain diameter of not more than 3.0 mcm and the second phase including at least one from martensite, bainite and austenite. In the surface layer, the average grain diameter of the second phase comprises not more than 2.0 mcm, difference (ΔnHav) between average nano-hardness (nHαav) of the main phase and average nano-hardness (nH2nd av) of the second phase comprises 6.0-10.0 GPa, difference (ΔσnH) of mean-square deviation of nano-hardness of the second phase and mean-square deviation of ferrite nano-hardness comprises not more than 1.5 GPa, and in the central part, difference (ΔnHav) between average nano-hardness values comprises at least 3.5 GPa to not more than 6.0 GPa, and difference (ΔσnH) between mean-square deviations of nano-hardness values comprises at least 1.5 GPa.
 Production of texture sheets from electrical steel / 2537628
Invention relates to metallurgy. Proposed process comprises production of slab to be rolled to sheet and continuous decarburising annealing. The latter includes heating of steel sheet at the rate of 50°C/s to 700°C-750°C or higher. Note here that at least at 500°C-700°C heating is performed in atmosphere with oxidative potential P(H2O)/P(H2)=0.05 or lower. Cooling is performed to below 700°C in atmosphere with oxidative potential P(H2O)/P(H2)=0.05 or lower. Reheating of steel sheet from 800°C to 900°C and holding thereat are carried out in atmosphere with oxidative potential P(H2O)/P(H2)=0.3 or higher.
 Method of production of electrical steel strip with oriented grains and electrical steel with oriented grains thus obtained / 2536150
Molten steel, doped with silicon, is continuously cast into a preform having a thickness in the range from 50 to 100 mm, and subjected to hot rolling in multiple unidirectional rolling mills for obtaining rolls of a finished hot rolled strip having a thickness ranging from 0.7 to 4.0 mm, followed by continuous annealing of the hot rolled strip, by cold rolling, continuous annealing of the cold rolled strip for the initiation of primary recrystallisation and optionally decarburisation and/or nitriding, applying of a coating on the annealed strip, annealing the strip wound in the roll to initiate secondary recrystallisation, continuous thermal levelling by annealing of the annealed strip and application on the annealed strip of the coating for electrical insulation, and the product thus obtained.
 Method for plate manufacture from non-textured electrical steel / 2534638
Invention involves hot rolling of initial material from steel containing the following, wt %: C not more than 0.03, Si not more than 4, Mn 0.03-3, Al not more than 3, S not more than 0.005, N not more than 0.005 and Fe and inevitable impurities are the rest; annealing in a hot zone; cold rolling and final annealing; size of a crystalline grain before cold rolling is brought to not more than 100 mcm, and final annealing is performed by quick heating to the temperature exceeding recrystallisation temperature at an average rate of temperature rise of at least 100°C/s.
 Cold-rolled steel plate having excellent quality of surface after forming, and its manufacturing method / 2532689
After forming, due to exclusion of formation of linear structures, steel containing the following (wt %) is made: 0.0005-0.0050 C, not more than 0.30 Si, not more than 0.50 Mn, not more than 0.050 P, not more than 0.020 S, 0.010-0.100 Ti and not more than 0.080 sol. Al, not more than 0.007 N and Fe and inevitable impurities are the rest provided that content of C, N, S and Ti meets the following ratio (I): ([%Ti]/48-[%N]/14-[%S]/32)/([%C]/12)≥1.00…(I), where [%M] represents content in the steel of element M (wt %); it is subject to hot rolling, etching, cold rolling, continuous annealing and cooling at the rate not exceeding 30˚C/s at the temperature interval of 400-200°C.
 Method for plate manufacture from textured electrical steel / 2532539
Manufacturing method of textured electrical plate steel involves manufacture of a steel slab, in which content of inhibitor components is reduced, i.e. content of Al of 100 ppm or less and content of N, S and Se of 50 ppm respectively, hot rolling of steel, and then, one cold rolling or two or more cold rolling operations with intermediate annealing operation(s) between them to obtain a steel plate of final thickness; annealing of the steel plate for primary recrystallisation and then annealing for secondary recrystallisation; besides, annealing for the primary recrystallisation includes heating of a steel plate to the temperature that is equal or higher than 700°C, at the heating rate of at least 150°C/s, cooling of the steel plate to the temperature of 700°C or lower, and then, heating of the steel plate to the exposure temperature at average heating rate of not more than 40°C/s in the next heating zone.
Production of thick-sheet rolled stock for ship building / 2530078
Austenitizing of the workpiece is performed at not over 1170°C to rough said workpiece to depth of intermediate blank defined by the relationship H=109+2·(h-33)±15 mm, where h is produced rolled stock depth. Then, intermediate blank is cooled to finish at temperature of finishing end temperature not lower than 730°C. Produced rolled sheet is cooled at higher rate to 470-600°C, then cooling is decelerated to not over 160°C. After decelerated cooling of rolled sheet, tempering is performed to 550-700°C. Note here that said blank is made from steel containing the following components, in wt. %: C<0.12, Si 0.15-0.35, Mn 1.00-1.50, V+Nb+Ti<0.20, Mo+Cr<0.40, (Cu+Ni) 0.15-0.50, iron and unavoidable impurities making the rest with content of every impurity less than 0.03.
 Method to produce sheet from unoriented electrical steel / 2529258
Steel slab contains the following substances, wt %: 0.01-0.1 C, maximum 4 Si, 0.05-3 Mn, maximum 3 Al, maximum 0.005 S, maximum 0.005 N, the rest is Fe and unavoidable impurities. It is subject to hot rolling, cold rolling and final annealing, the latter is performed under the following conditions: average rate of temperature increase in the course of sheet heating amounts to at least 100°C/s, and the curing temperature falls within the temperature range of 750-1100°C.
 Surface hardening by cutting-forming tool / 2556897
Invention relates to machine building, particularly, to surface hardening with production of quenched structures. To up wear resistance of parts from quenched metals, primarily, of iron-carbon alloys and to get hardened surface layer with uniform properties, part surface layers is cut layer-by-layer over narrow side by cutter with cutting and forming edges. Note here that cut layers are deformed by tool working surfaces. Then, cut layers are placed on the part by the tool forming edge. In cutting of surface layer, its plastic straining and friction against the tool, tool geometrical parameters and machining parameters are selected to heat cut layer above phase transition temperatures for given machine material. Cut layer is cooled down by conductive heat removal to the blank or by appropriate cooling means.
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FIELD: process engineering. SUBSTANCE: invention relates to metallurgy, particularly, to production of metal strip with mechanical properties varying over strip width. The strip is heated, cooled and overaged at continuous annealing. Note here that at least one of the following parameters varies over the strip width: heating rate, maximum temperature, holding duration at maximum temperature and cooling trajectory after maximum temperature. Note here that at least one of the following parameters varies over the strip width at overaging: rate of heating to maximum temperature, duration of holding at maximum temperature, cooling trajectory after maximum temperature, overaging temperature, duration of holding at overaging temperature, minimum temperature before reaging and rate of heating to reaging temperature. Note here that at least one cooling trajectory follows the nonlinear temperature-time curve. EFFECT: metal strip with mechanical properties varying over strip width. 15 cl, 8 tbl, 4 dwg
The invention relates to a method of heat treatment of metal strip material to produce mechanical properties that differ over the width of the strip. The invention also relates to a strip material obtained in this way. Usually steel strip material after rolling is subjected to continuous annealing for making strip material the desired mechanical properties. After annealing at strip material may be coated, for example, by hot dip galvanizing, and/or it may be subjected to training to give the desired surface properties of the strip material. Annealing is performed by heating the strip with a certain heating rate, the shutter speed of the strip at a certain temperature exposure during a certain period of aging and cooling the strip at a certain speed cooling. For some purposes during the cooling of the strip temperature to leave a permanent for a certain period of time for the purpose of perestiani strip. This conventional method provides continuous annealing mechanical properties of the strip that are constant along the length and across the width of the strip. This strip is cut into blanks, intended for instance for the automotive industry. For certain purposes, mostly for automotive technicians�the diesel industry requires billet, which has areas with different mechanical properties. These blanks are usually made by producing two or more bands having different mechanical properties, cutting out parts of the blanks from these bands and welding together two or more pieces of workpieces having different mechanical properties, to obtain a single piece. May also be welded together strips and then cut the workpiece from the combined strip. Thus, can be formed in part for the unpainted body, which, for example, is at one end of the mechanical properties that differ from the mechanical properties on the other end. However, these so-called "composite" or "stitched" blanks have the disadvantage that the welds form a special zone associated with heating during welding, reducing, thus, the workpiece during the forming operation of the workpiece. Japanese patent application JP2001011541A provides a method of producing a composite steel strip for stamping at which the mechanical properties vary across the strip width. According to the first embodiment, the mechanical properties vary across the strip width by changing the cooling rate across the strip width at the time when the strip leaves the continuous annealing furnace. Japanese patent application mentions in Kutch�TVE second option the change in the mechanical properties across the strip width by adjusting the value of nitriding or carburizing across the strip width. The third option according to Japanese patent application consists in using steel strip that has two or more values of the sheet thickness across the strip width. According to Japanese patent application JP2001011541A have some drawbacks. A third option is possible only in the case where the thickness of the strip symmetrically distributed across the strip width. The second option is using a nitriding or carburizing is not suitable for rapid technological process that is currently required in the steel industry. The first option provides only a limited variation of mechanical properties within the example given in this document. The aim of the invention is to propose a method of heat treatment of strip material, providing the variation of mechanical properties across the strip width, which can be performed when economically feasible speeds. Another objective of the invention is to propose a method of heat treatment of strip material, providing the variation of mechanical properties across the strip width, which makes achievable the variation of mechanical properties within a wide range. A further aim of the invention is to propose a method of heat treatment of strip material, providing the variation of mechanical properties across the Shire�not stripes and which can be used by other processing techniques compared to existing technical solutions. In addition, the invention aims to offer a strip of material having mechanical properties that differ over the width of the strip. One or more of the objectives of the invention are achieved by a method of heat treatment of metal strip material providing mechanical properties that differ over the width of the strip when the strip is heated and cooled and optionally perestaivayut during continuous annealing, characterized in that at least one of the following options in the method varies across the width of the stripes: - heating rate: - the highest temperature - the exposure time at maximum temperature - the trajectory of the cooling from the highest temperature or when you run perestiani to at least one of the following options in the way that differed in bandwidth: - heating rate: - the highest temperature - the exposure time at maximum temperature - the trajectory of the cooling from the highest temperature - temperature perestiani - the duration of exposure at a temperature of perestiani - the lowest temperature of cooling before pedestrianism - speed �of tograve to a temperature of perestiani and wherein at least one of the trajectories after cooling higher temperature follows a nonlinear curve of temperature-time. The inventors found that each of the above parameters, alone or in combination, when given a value that varies across the width of the stripes, gives the mechanical properties that also vary in width. This invention provides, therefore, different ways of obtaining a strip of material having mechanical properties that vary across the strip width, and the invention makes it possible to adjust the mechanical properties of the strip material across the width of the strip in exact accordance with the wishes of the end user of the strip, which uses a "composite" of the workpiece, for example of the automobile manufacturer that uses these blanks for forming blanks for unpainted body. Nonlinear curve of temperature-time means that the cooling rate is purposefully changed soon after the beginning of the trajectory of cooling, above 200°C. According to a preferred implementation variant the highest temperature varies in two or more zones of the strip width, and optionally, also the cooling trajectory after the exposure period at the highest temperature is different on the two or more zones of the strip width. The most�most of the heat treatment temperature has a great influence on the mechanical properties of the strip and therefore very suitable to produce different mechanical properties in different width zones of the strip. The cooling trajectory after the exposure period at maximum temperature conditions may be added here, as explained above. Preferably the highest temperature in at least one zone width is in the range of AC1 temperature to a temperature of AC3 and the highest temperature in at least one other zone width is greater than the AC3 temperature. The use of these temperature ranges provides a strong variation of mechanical properties. Alternatively, the highest temperature in at least one zone width below the AC1 temperature and the highest temperature in at least one other zone width is in the range of AC1 temperature to a temperature of AC3. The use of this or the above options depends of course on the type of metal and the purpose for which it will be used. According to an alternative embodiment, the highest temperature in at least one zone width is greater than the AC3 temperature, and the highest temperature in at least one other zone width below the AC1 temperature. For this alternative, fairly the same position as above. According to another alternative embodiment, the highest temperature in at least two areas across the width is in the range of AC1 temperature to a temperature of AC3 and there R�slice temperatures, equal to at least 20°C between the two highest temperatures in these two zones in width. The use of this alternative, or one of the features mentioned above and depends on the type of steel used and the purpose for which will be used strip material. According to another preferred variant implementation of the cooling trajectory differ in two or more zones of the strip width and at least one of the cooling trajectories follows a nonlinear curve of temperature-time. This means, for example, that in one area the width of the cooling rate changes from 5 to 40°C/h after the first time period of cooling, while the other zone width from the beginning is cooled at a rate of 40°C/sec. According to a preferred implementation variant operation performed perestiani, and temperature perestiani varies in two or more zones of the strip width and/or the lowest temperature of cooling before pedestrianism differs on the two or more zones of the strip width. Thus, the operation of the process of perestiani is used to vary the mechanical properties in the areas of a metal strip width. Often different temperature perestiani used in combination with different maximum temperatures�. According to this variant implementation preferably, the duration of incubation at a temperature of perestiani is from 10 to 1000 seconds, more preferably, the duration of incubation at a temperature of perestiani varies in two or more zones of the strip width. This measure provides an accurate method of variation of mechanical properties in the zones of the strip width. According to another preferred implementation variant, the heating rate and/or rate of heating to a temperature of perestiani varies in two or more zones of the strip width. The rates of heating ensure a good approach to vary the mechanical properties, often in combination with other parameters. According to a special variant implementation, at least one of process parameters gradually changed to at least part of the bandwidth. Thus the mechanical properties gradually change across the strip width, which can be very handy for parts produced from blanks cut from such strip. These gradually varying properties cannot be obtained using the "multipart" welded blanks. In most cases, the strip is a steel strip, high-strength low alloy steel (HSLA), dual phase steel (DP) or TRIP-steels (TRIP). However, the method can �also be used for aluminum strips. According to another preferred implementation variant, at least one parameter that varies across the width of the strip changes its value at least at one point of time when processing of the strip. According to another preferred implementation variant, at least one other parameter selected in order to vary the width of the strip at least at one point of time when processing of the strip. The way the mechanical properties of the strip varies along the length of the strip, so that one lane out of two or more cut with different changing properties along the length of the strip. This can be convenient in the manufacture of strip length many hundreds of meters, which should only be a relatively small series of parts. The invention also relates to a strip material having mechanical properties that differ over the width of the strip and produced according to the method disclosed above. The invention will be described with reference to four examples for which the attached drawings shows a series of temperature-time and schematic distribution of zones in the annealed composite strips. Fig. 1 shows an example of a variable in place of annealing steel strip using various greatest temperatures above the AC1, d�I various areas of the strip width; Fig. 2 shows an example of a variable in place of annealing steel strip using different highest temperatures, one of which is below the AC1 and the other above the AC1, for different zones of the strip width; Fig. 3 shows an example of a variable in place of annealing steel strip using variable speeds for cooling at least one zone of the strip width; Fig. 4 shows an example of a variable in place of annealing steel strip using different intermediate exposure or temperature perestiani. As a first example annealed composite strip in which the various zones across the width heated to different highest temperatures, each of which exceeds the AC1 temperature. Some components for the automotive industry require different magnitudes of the moldability, which can adequately be described in terms of the total elongation. One of the ways to achieve different values of the total elongation is to obtain a changing two-phase microstructures with different volume fractions of martensite in ferrite basis. The increase in the volume fraction of martensite increases the strength and reduces the elongation. Different volume fractions of ferrite-martensite is achieved by heating up to different highest temperatures, as shown nafig. 1A. The example shown in Fig. 1b is a steel strip with controlled place by annealing for an arc of the roof in a car unpainted body. There are three zones (not including transition regions), where the two outer zones have the same time-temperature cycle and the average area is different. The letter L refers to the direction along the length of the strip. Outdoor areas (A1 and A2) require a higher ductility and are therefore heated to a higher temperature of about 780°C for 30 seconds, while the Central region (C) is heated to a higher temperature of 830°C for 30 seconds. Different the highest temperatures give different amount of austenite at the end of the time-temperature cycle. After heating to the highest temperatures of the entire strip is cooled at a rate of 30°C/h to less than 200°C, and then subjected to natural cooling. The dotted line in Fig. 1b shows the shape of the workpiece, which must be cut from the strip and to be used for forming the component. Chemical composition is shown as an example of the material are given in table.1, and the properties after this treatment are shown in table.2.
As a second example annealed composite strip in which the various zones across the width heated to different highest temperatures both above and below the AC1 temperature. Two threshold conditions in regard to the strength-ductility, �have a quiet can be achieved in the steel strip, are recrystallized ferrite with high formability and only martensite with high strength and low ductility. Typically, the plasticity of martensite is too low to achieve any noticeable formability. Instead of martensite can be used fully bainite structure, which is formed at lower cooling rates and which has a lower strength, but more plastic. Such boundary conditions can be useful to use the maximum ductility of this material in some areas of a part requiring high formability, while other areas have low requirements for plasticity and they preferred high strength. In the example shown in Fig. 2, variable according to the place annealing using the principle of various greatest temperatures below and above the AC3 is used for the manufacture of steel strip, is optimally suitable for a component of the bumper beam. In the example shown in Fig. 2b, the strip is annealed in three different zones across the width, where the two outer zones (A1 and A2) have the same temperature below the AC3 (720°C) and average area (In) is at a higher temperature (860°C), in this case exceeding AC3, see chart temperature time Fig. 2A. The letter L refers to the direction along the length of the strip. The initial state proyavlyaetsya state after cold rolling, and during the annealing of the material in zones A1 and A2 recrystallized, becoming equiaxed ferrite with large carbides and pearlite. The cooling rate from this temperature is not critical, but for convenience equal to 20°C/h. Zone is heated to a higher temperature and in this case it exceeds the AC3, so there is a complete transformation to austenite. This area is cooled at 80°C/h for the formation of a fully bainitic microstructure. The dotted line in Fig. 2b shows a shape of the workpiece, which must be cut from the strip and to be used for molding parts. Chemical composition is shown as an example of the material are given in table.3, and the properties after this treatment are shown in table.4.
As a third example is annealed composite strip in which the various zones across the width is cooled by different cooling trajectory. Multipath path of cooling can be used to accelerate the development of certain phases or microstructures that arise when using a constant cooling rate. Slower cooling at higher temperatures increases the proportion of formation of ferrite during the period compared with cooling at a constant higher speed. The following example uses this phenomenon and is an example of three different zones of the strip width. This example of the annealed composite strip is optimized for the a-pillar of the car body shown�Oh Fig. 3b. Shown by a dotted line indicates the shape of the workpiece, you need to cut out the strips and which will be used to form the component. The letter L denotes the direction along the length of the strip. Requires three zones across the width with the increasing demands for ductility from A, b to C. First, the entire band is heated with the same heating rate to a temperature above the AC3 temperature, during the holding period, long enough for a complete austenitic transformation in the steel strip. Zone a has the lowest requirements to plasticity, which can be sufficiently ensured a fully bainitic microstructure, which is formed at a time when steel is cooled at a rate of 40°C/h, demonstrating a linear trajectory of cooling above 200°C in Fig. 3A. Zones b and C are cooled both with relatively low speed of approximately 5°C/h, but in different periods, limited time, when reaching a certain temperature, see chart temperature time Fig. 3A, showing the nonlinear trajectory of cooling for zones b and C. When the temperature of the zone In reaches 720°C, the cooling rate is increased to 40°C/h and likewise in zone C, the cooling rate is increased to 40°C/h, when the temperature reaches 600°C. During cooling at a speed of 5°C/h in zones b and C ADR�unit transforms into ferrite. With increasing the cooling rate further transformation into ferrite slows down and as soon as the remaining austenite is cooled to a temperature below approximately 350°C, it transforms into martensite. Compared with the zone In the zone is maintained at higher temperatures for longer periods because of long period with a lower cooling rate. This means that in the zone is formed With more ferrite and thus the area becomes higher formability. Chemical composition is shown as an example of the material are given in table.5, and the properties after this treatment are shown in table.6.
As a fourth example is annealed composite strip in which the various zones across the width is cooled using different intermediate shutter speed or temperature perestiani. Requirements for formability of some components is not completely described in terms of only the total elongation, but better described in combination with another criterion, such as onlinemost holes. Two-phase microstructure provide a good strength-ductility, however, the ferrite-bainite mixture secure the best property onlinemost holes than the ferritic-martensitic. The example shown in Fig. 4b, is the solution for posterior longitudinal component of motor unpainted body. The letter L denotes the direction along the length of the strip. In this example, the entire band is heated with the same heating rate and then vyderjivaut equal to the maximum temperature of 840°C for the same exposure time 30 seconds to complete transformation to austenite, see Fig. 4A. After that, the entire band is evenly cooled with the same cooling rate 30°C/h until a temperature of about 540°C. During this first stage cooling, the ferrite again increases in order to again become the dominant phase. After reaching a temperature of 540°C zone And incubated for 30 seconds at this temperature, while the area is cooled further to a temperature of 400°C and then maintained at this temperature for 30 seconds. After performing intermediate annealing two zones is cooled to at least 200°C at a cooling rate of at least 20°C/sec. Regarding the chemical composition shown in table.7, different fraction of bainitic will be formed between two different intermediate temperatures used for zones A and B. At a higher temperature exposure in the area And the kinetics of transformation of austenite to bainite is relatively slow and, thus, the final fraction consists mostly of ferrite and martensite with a relatively small fraction of bainitic. In the zone At a lower temperature than the intermediate exposure kinetics of transformation of austenite to bainite is relatively high and, thus, the final fraction consists mostly of ferrite and bainitic and a relatively small proportion of martensite. The chemical composition is given as p�imera material are shown in table.7, and properties after this treatment are shown in table.8.
It should be clear that in the examples above, the chemical composition �showing only the main elements. Of course, there are the inevitable impurities, but can also be other elements, and the rest is accounted for by iron. 1. Method of heat treatment of metal strip material providing different mechanical properties across the width of the strip, wherein the strip is heated, cooled and, if necessary, perestaivayut during continuous annealing, characterized in that at least one of the following options provide different heat treatment on the width of the strip: heating rate, maximum temperature, duration of exposure at the higher temperature, the cooling trajectory of the maximum temperature or when perestiani at least one of the following options provide different width of strip: heating rate, maximum temperature, duration of exposure at the higher temperature, the trajectory of the cooling from the highest temperature temperature perestiani, the duration of exposure at a temperature of perestiani, the lowest temperature of cooling before pedestrianism, the rate of heating to a temperature of perestiani, wherein at least one of the trajectories after cooling higher temperature follows a nonlinear curve of temperature-time. 2. A method according to claim 1, wherein the highest temperature mentioned in two different and�or more zones of the strip width and optional cooling trajectory after the holding period at the highest temperature is different on the two or more zones of the strip width. 3. A method according to claim 1 or 2, in which the highest temperature in at least one zone width is in the range from temperature Ac1to the temperature of the Al3and the highest temperature in at least one other zone width is greater than the temperature of the Al3. 4. A method according to claim 1 or 2, in which the highest temperature in at least one zone width below the temperature of the Ac1and the highest temperature in at least one other zone width is in the range from temperature Ac1to the temperature of the Al3. 5. A method according to claim 1 or 2, in which the highest temperature in at least one zone width is greater than the temperature of the Al3and the highest temperature in at least one other zone width below the temperature of the Ac1. 6. A method according to claim 1 or 2, in which the highest temperature in at least two areas across the width is in the range from temperature Ac1to the temperature of the Al3and there is a difference of temperature equal to at least 20°C between the two highest temperatures. 7. A method according to claim 1 or 2, wherein the cooling trajectory differ in two or more zones of the strip width and at least one of the cooling trajectories follows a nonlinear curve of temperature-time. 8. A method according to claim 1 or 2, wherein when performing peristeris�of temperature perestiani are distinguished in two or more zones of the strip width and/or the lowest temperature of cooling before pedestrianism distinguish these two or more zones of the strip width. 9. A method according to claim 8, in which the duration of exposure at a temperature of perestiani is from 10 to 1000 seconds, more preferably, the exposure time at a temperature of perestiani distinguish between two or more zones of the strip width. 10. A method according to claim 1 or 2, in which the heating rate and/or rate of heating to a temperature of perestiani distinguish between two or more zones of the strip width. 11. A method according to claim 1, wherein at least one of the parameters gradually change on at least part of the bandwidth. 12. A method according to claim 1 or 2, wherein the strip is a steel strip, preferably a steel strip of high strength low alloy steel (HSLA), dual phase steel (DP) or TRIP-steels (TRIP). 13. A method according to claim 1 or 2, wherein at least a value of one parameter, which differ in bandwidth, change in at least one time during the processing of the strip. 14. A method according to claim 1 or 2, in which optionally at least one other parameter is selected in order to distinguish it across the strip width at least at one point of time when processing of the strip. 15. A strip of metallic material having mechanical properties that are different in width of the strip obtained by the method according to any one of claims. 1-14.
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