Honeycomb substrates for catalyst converters for two-wheeled or diesel vehicles
FIELD: production of honeycomb substrates for catalyst converters for two-wheeled or diesel vehicles.
SUBSTANCE: the invention is dealt with production of honeycomb substrates made out metal sheets piled or rolled in a package and minimized to the honeycomb elements used first of all as honeycomb substrates for catalyst converters in the systems of exhaust gas (EG) neutralization. There is a description of a honeycomb element (1) first of all as a honeycomb substrate for a catalyst converter for systems of two-wheeled vehicles exhaust gas neutralization. The honeycomb substrate for catalyst converter consists of some layers of metal sheets (2, 3) packed as a package or minimized in a roll, which are at least on separate sections are structured or profiled in such a manner, that they form for EG flowing channels (4). At that the metal sheets (2, 3) represent the sheets of high-quality steel of more than 0.08 mm thick with a share of aluminum from 6 up to 12 mass % multiplied by 0.02 mm and divide by "d" - thickness of the metal sheets (2, 3). The technical result - a possibility to use metal sheets depending on the share of aluminum in them and their thickness, that allows to use the sheets taken from production process of manufacture of a material subjected to a hot aluminization.
EFFECT: the invention ensures a possibility to use metal sheets for the purpose depending on the share of aluminum in them and their thickness.
5 cl, 1 dwg
The present invention relates to manufactured from typed in the package or rolled metal sheets cell element used primarily as a carrier of a catalytic Converter systems neutralization of exhaust gases. Such cell elements are usually made of alternating layers of alternating smooth and corrugated metal sheets or alternately alternating layers of differently structured or profiled metal sheets, which roll in a roll or trying to enter the package. These cellular elements are described, for example, in the application WO 94/13939.
Because the EXHAUST systems of internal combustion engines (ice) are usually dominated by high temperature and corrosive environment, as materials for the manufacture of such cell elements hitherto mainly used resistant to high temperature corrosion of alloys, i.e. alloys based on iron with a high content of chromium and aluminum.
Despite the fact that, as is well known, with the increase in stainless steel the aluminum content such have become increasingly difficult to treat, resulting in the rolling process such material must be constantly heated to a high temperature (heat), however, in modern developments observed ones is a tendency toward the use for the manufacture of cellular metal materials with higher aluminum content. This is confirmed proposed in patent US 4602001 solution, whereby an attempt was made to compensate for the poor machinability of steel with a high content of aluminum by increasing the aluminum content only at the subsequent stages by applying additional layers of aluminium and its diffusion in the underlying material.
As proposed in the application DE 4410744 also there is a trend towards the use of materials with a high content of aluminum even though the priority in this case is given to providing the necessary electrical properties.
In addition, in modern developments, we have also observed a trend towards the use of thinner metal sheets, because with the reduction of mass media the catalytic Converter improve its characteristics during starting and warming up the engine, and the thin walls reduce pressure loss in the catalytic Converter. However, with decreasing thickness of the metal sheets worsens the ratio between the quantity present in the metal sheets of aluminum and surface area, and this ratio is the key indicator in determining the durability of the corrosion resistance of the metal sheets. This explains the trend towards the use of thinner sheets of foil with growing with what uranium aluminum even though the result is considerably complicated the process rolling.
The tendency to reduce the thickness of sheet metal for the manufacture of cellular elements can be traced, for example, and in the application DE 4418630.
However, it was found that there are specific applications metal cellular elements, that are not subject to the above. In such applications the cellular elements are mainly of the EXHAUST system two-wheeled vehicles, where cell element is exposed to such a high mechanical loads, which for its manufacture, on the contrary, you want to apply a thicker foil. In addition, another area of application of the metal cellular elements are system EXHAUST aftertreatment for diesel engines that is dominated by a much lower temperature compared to the EXHAUST systems of engines with forced (spark) ignition mixture. Therefore, the above General approaches, fair for other applications cellular elements need not necessarily be applicable in respect of the above two specific applications metal cellular elements.
Based on the foregoing, the present invention was based on the task of developing suitable for these areas primeneniye elements, that would be particularly cost-effective to manufacture.
This problem is solved by using cell element according to claim 1 or 2 claims, intended primarily for EXHAUST aftertreatment systems for two-wheeled vehicles, as well as using cell element according to claim 5 of the formula used to EXHAUST aftertreatment systems for diesel vehicles. Preferred embodiments of the invention are provided in the respective dependent claims.
Modern developments in the field of manufacturing technology metal sheets with a high content of aluminum is based on the use of multi-methods in the first stage of which the thickness of the steel sheet with a lower content of aluminum is reduced by rolling to a certain size, and then in the second stage to increase the aluminium content and the thickness of the sheets is brought to final size. The content of aluminum can be improved by nowelcome (cladding), aluminum foil, or by hot plating or by immersion in molten aluminum. For such technological processes have been developed methods of rolling, which allow relatively low cost and above all without frequent intermediate cycles of heating to expose rolling steel with maximum content of the aluminum is 4.5%.
The present invention is based on the use of the fact that such materials despite the content of aluminum is less than 4.5, or even less than 4% have sufficient resistance to high temperature corrosion for use in cellular elements in the form of metal sheets of a thickness exceeding 0,06 mm, preferably more than 0.08 mm In having such a thickness of the metal sheets, the ratio of the total number present them in aluminum to surface area when the content of aluminum is 3 or 4%, even higher in comparison with metal sheets of a thickness of, for example, 0.03 mm and aluminum content of 6%. Since at high temperatures the aluminum exceptionally rapidly diffuses in the amount of steel on the surface of thicker metal sheets and at a lower content of aluminum is present in sufficient quantity, which is enough to eliminate possible damage present on the surface of the metal sheets of the protective oxide layer due to the formation of a new layer of aluminum oxide.
For metal sheets of a thickness exceeding 0,06 mm approximate fair dependence, according to which the aluminum content (in mass percent) must lie in the range from 6 to 12%, especially from 8 to 10%, multiplied by 0.02 mm and divided by the thickness of the metal sheets. Thus the ratio between the total quantity present of aluminum and the surface area for these metal sheets in all cases closer to optimal than a metal sheet with a thickness of 0.02 mm and a content of aluminium 6%.
In systems EXHAUST aftertreatment two-wheeled vehicles, dominated by high mechanical loads, and in some other applications you want to use metal sheets with thickness from 0.08 to 0.12 mm Therefore, for such applications suitable metal sheets aluminum content in the range from 1.0 to 4.5%. Typically, these steel sheets contain chromium in an amount of from 15 to 25% and rare earth elements in a certain amount, and in respect of these and other alloying elements in stainless steels, and is fair in this case known conditions.
Obviously, thicker metal sheets are not amenable to small-scale profiling or structuring, and therefore proposed in the invention of cell elements, the number of cells in the cellular structure, the form of which cell element has in cross-section, is usually from 200 to 600 cells per square inch.
A particular advantage of the present invention, associated with the economic aspects, is that as a material for the manufacture of the carrier catalyst for two-wheeled vehicles, you can use the material obtained in other industrial processes not directly related to the production of honeycomb elements for the system of the EXHAUST aftertreatment vehicles diesel vehicles. The result is the ability to make the necessary for production of honeycomb element material more accessible, reducing associated with its production costs, even in cases when you want to use a relatively small quantity of such material. Such profitability is impossible to achieve in the case of short-run production of EXHAUST aftertreatment systems for two-wheeled vehicles, when would be required to conduct a relatively small volume of melting metal and subjected to rolling special types of foil. Since, however, stainless steel with aluminium content of 1.0 to 4.5% in any case used in the above-described multi-stage processes with the subsequent increase of the content in this steel, aluminum, there is a possibility to apply part of this material directly for the manufacture of cellular elements, especially in these processes such material in any case receive acceptable for use according to the invention the thickness as an intermediate product at the stage of increasing the aluminum content.
The above is true of EXHAUST aftertreatment systems for diesel vehicles. In such systems is dominated by significantly lower temperatures compared to systems Nate is the realization of the EXHAUST gas of engines with positive ignition of the working mixture, and therefore in such systems is quite acceptable use metal with a lower content of aluminum and related lower resistance to high temperature corrosion. Although such systems, taking into account prevailing in mechanical loads and there is no need to use metal sheets of the same great thickness, and systems for two-wheeled vehicles, such neutralization systems for diesel engines is not required and an equally high correlation between the total quantity of aluminum and surface area. Therefore, the above-described foil sheets, which is obtained as an intermediate product during not associated directly with the production of honeycomb elements for EXHAUST aftertreatment systems vehicles diesel vehicles of the production process and the aluminum content is from 1.0 to 4.5%, can be subjected to further rolling to reduce the thickness to the desired value, component of, for example, from 0.03 to 0.06 mm, and then despite the lower content of aluminum easily use in EXHAUST aftertreatment systems for diesel cars. In this case also achieved significant economic impact due to the absence of individual production cycles.
Below the invention is illustrated on p is the iMER typical metal carrier catalyst with reference to the accompanying drawing.
Cell element 1, made of layers of smooth 2 and 3 corrugated metal sheets of thickness d from 0.08 to 0.12 mm, is located in the tubular casing 5. The metal sheets 2, 3 form a flowing EXHAUST gas channels 4 and are preferably of such size that cell element had from 200 to 600 cells per square inch. The metal sheets are made of high quality steel with a chromium content of 15-25 wt.%, preferably from 18 to 22 wt.%, with a typical content of certain rare earth elements used, as is known to increase the corrosion resistance, and aluminum content from 1.0 to 4.5 wt.%, mainly from 2 to 4 wt.%.
Thus, the present invention offers a particularly cost-effective method of manufacturing a carrier catalyst with agreed at a qualitative level with the surrounding conditions parameters for EXHAUST aftertreatment systems for two-wheeled and diesel vehicles.
1. Cell element (1)is primarily a carrier catalyst systems for neutralization of exhaust gases of a two-wheeled vehicles, consisting of layers typed in the package or rolled metal sheets (2, 3)that at least some sections are structured or profiled in such a way that they form a flowing EXHAUST gas channels (4), from which causesa fact, what metal sheets (2, 3) represent the sheets of stainless steel of a thickness exceeding 0.08 mm aluminum content of 6-12 wt.%, multiplied by 0.02 mm and divided by the thickness (d) metal sheets (2, 3).
2. Cell element (1) according to claim 1, characterized in that the thickness (d) metal sheets (2, 3) is 0,08-0,12 mm
3. Cell element (1) according to claim 1 or 2, characterized in that the number of channels (4) in the mobile element (1) is between 200 and 600 cells per square inch.
4. Cell element (1) according to any one of claims 1 to 3, characterized in that the aluminium content is 2-4 wt.%.
5. Cell element (1) according to any one of claims 1 to 4, characterized in that the metal sheets (2, 3) are made by rolling, primarily represent the leaves, taken from the production process being hot elyuminirovanie material to the stage of increase in its aluminum content.