CS276019B6 - High-alloyed Heat-resistant steel - Google Patents

Abstract

The invention relates to a steel with a heat resistance of up to 1400 ° C with the ability to form a moldable foil, suitable for catalytic devices, as well as for passports and wires for heating resistance purposes. The steel contains 0.005 to 0.10% carbon, 0.15 to 0.60% manganese, 0.008 to 1.50% silicon, 0.008 to 0.06% phosphorus, 0.005 to 0.02% sulfur, 18 to 32% by weight. % chromium, 3.5 to 6.5% aluminum, 0.01 to 0.03% nitrogen, traces up to 0.3% nickel, traces up to 0.1% zirconium, 0.005 to 0.05% cerium, traces up to 0.003 % boron, 0.005-0.020% barium, traces up to 0.005 calcium, traces up to 0.01% yttrium.

Description

The invention relates to high-alloy refractory steel for use in the manufacture of a catalytic device which makes it possible to reduce the content of harmful emissions arising from the combustion of motor vehicle fuel mixtures in the form of foils, wires and belts.

So far, it has not been possible to produce steel for this purpose that is characterized by good hot and cold formability to be processed into a thin film, thin wire and strip, while retaining the ability to meet the demanding requirements of subsequent forming. cold with simultaneous heat resistance up to a temperature of 1,400 ° C and with a specific electrical resistance of 1,330 to 1,470 ohms.mm “ ² .

These disadvantages are eliminated by high-alloy steel, the composition of which according to the invention is 0.005 to 0.10% of carbon, 0.15 to 0.60% of manganese, 0.008 to 1.50% of silicon, 0.008 to 0.06% of phosphorus, 0.005 to 0%. 02% sulfur, 18 to 32% chromium, 3.5 to 6.5% aluminum, 0.01 to 0.03% nitrogen, traces up to 0.3% nickel, traces up to 0.1% zirconium, 0.005 to 0, 05% cerium, traces up to 0.03 boron, 0.005 to 0.020% barium, traces up to 0.005% calcium, traces up to 0.01 yttrium, the remainder iron. '

The advantage of the steel according to the invention is the possibility of forming up to the shape of a foil, which foil can be further shaped by bending, pressing, shortening into complex shapes without breaking it. At the same time, the steel retains its heat resistance up to a temperature of 1,400 ° C. In addition to the use in the form of a foil, the steel can be used in the form of a wire and a strip for heating resistance use, because the value of the specific electrical resistance is in the range of 1.330 to 1.470 ohms. , nun, while the design of the wire strip allows cold processing, without breaking by bending, twisting and shortening. I Example 1

Steel with 0.057% carbon, 0.28% manganese, 0.46% silicon, 0.025% phosphorus, 0.006% sulfur, 21.30% chromium, 0.15% nickel, 4.5S% aluminum, 0.02% by weight nitrogen, 0.04% zirconium, 0.009% carium, 0.001% boron, 0.008% barium, 0.001% calcium, traces of yttrium, after casting hot formed in the temperature range of 1,100 to 830 ° C to a circular cross-section of 70 mm and after division and mechanical removal of surface defects and inspection, the semi-finished products were hot rolled at a temperature range of 1,040 to 840 ° C to 57 x 3 mm in coils and these coils after annealing in a chamber electric furnace at 840 ° C for 60 minutes and cooling in The water was further cold rolled to a thickness of 57 x 1 mm, followed by regrinding, followed by annealing in a continuous furnace at 840 ° C for 7 minutes and cooling in air. After annealing, it was cold rolled to a thickness of 0.1 mm, followed by longitudinal shearing and stress relief annealing in a continuous furnace at 840 ° C for 7 minutes and cooling in air. After annealing, it was cold rolled to a thickness of 0.1 mm, followed by longitudinal shearing and stress relief annealing in a continuous furnace at 840 ° C for 5 minutes and cooling in air. This annealing was followed by cold rolling to a final thickness of 0.04 mm. After rolling, the rolled film was assembled in the form of a grid in the catalyst, which is filled with active substance during the combustion of the fuel mixture during the operation of the motor vehicle.

Example 2

Steel with 0.022% carbon, 0.25% manganese, 0.40% silicon, 0.011% phosphorus, 0.009% sulfur, 20.80% chromium, 0.12% nickel, 5.02% aluminum, 0.015% nitrogen, 0.075% zirconium, 0.006% cerium, 0.0015% boron, 0.006% barium, 0.001. % of yttrium and traces of calcium, after casting into quadratic ingots weighing 1.25 tonnes, hot-formed at temperatures of 1 120 to 850 ° C to a circular cross-section of 70 mm and after cutting, mechanical removal of surface defects and inspection, semi-finished products were rolled in the temperature range 1 020 to 830 ° C into a wire with a diameter of 5.5 mm. After annealing in an electric furnace at 840 ° C for 20 minutes and cooling in water and subsequent pickling in a bath of NaOH + NaNO 2 / HCl / HNO 2, drawing to a final diameter of 2 mm followed. Drawing was followed by final annealing in a drawing oven at 840 ° C for 10 minutes and cooling in water. The final drawn wire was wound into a spiral, which was used as a heating element of an electric furnace with an operating temperature of 1250 ° C.

- OS 276 019 B6 ’2

The heat-resistant steel according to the invention is suitable for use in components of catalytic devices, in the form of foils in thicknesses of 0.1 to 0.02 mm and widths of 10 to 180 mm and in the form of wire with a diameter of 0.1 to 6 mm or strips. in widths from 3 to 180 mm and thicknesses from 0.1 to 2.5 for the production of heating resistance elements.

Claims (1)

PATENT CLAIMS. High-alloy heat-resistant steel for the production of catalytic combustors and for the production of heating resistance elements, characterized in that it contains in an amount of 0.005 to 0.10% by weight of carbon, 0.15 to 0.60% of manganese, 0.008 to 1.50% of silicon, 0.008 to 0.06% phosphorus, 0.005 to 0.02% sulfur, 18 to 32% chromium, 3.5 to 6.5% aluminum, 0.01 to 0.03% nitrogen, atopes up to 0.3% nickel, traces up to 0.1% zirconium, 0.005 to 0.05% cerium, traces up to 0.003% boron, 0.005 to 0.020% barium, traces up to 0.005% calcium, traces up to 0.01% yttrium.