DE1771266C3 - Process for the continuous production of coated steel strips - Google Patents

Description

To solve this problem, according to the invention, was intended to diffuse in. If, on the other hand, it is intended that a steel strip with an aluminum in the liquid or pasty state diffuses a carbon content below 0.2%, preferably below 55, then the annealing temperature is 0.005 ⁰ O, and a silicon content below 4 ° 0 out- range from 650 to 1100 "C.

is gone and that the coated strip is now used as a coating

The material is sprayed onto the cold rolling of a recrystallization heating, so the diffusion annealing takes place at about 700 ° C for a period of about at temperatures between 950 and 1200 ° C. This Is subjected to 2 hours. 60 temperatures are maintained until

The occurrence of recrystallization phenomena in the coating metal to the desired depth the steel strip has already diffused in due to the effect of elevated temperatures. The depth of diffusion known ("Materials and Corrosion", 1962, No. 5, can range from a few microns to the entire thickness of the Pp. 271, 272). The beneficial effects go under the steel band. Especially with a chrome bedes claimed method is there however not 65 layering, the steel strip can be increased, however recognized. carbon content still below 0.2%

The method according to the invention cannot be shown
The steel strip to be coated, from which the

went wild, can already be cold-rolled or cold-rolled $ a. It is also possible, especially with dikken Coatings to spray several individual layers, possibly made of different Coating metal can exist. Can also be on the opposite two sides different coating metals of the steel strip and these possibly also in different Thick ones are sprayed on. This depends on the use of the steel strips to be produced or, according to the desired properties.

In this way, steel strips can be produced which have the properties required in each case in an optimal way V / eise correspond. These properties include in particular corrosion resistance, wear resistance, smooth surface, homogeneity, strength and Adhesiveness of the coating as well as easy deformability and processability.

Claims (1)

wall, it also leads to a product Claim · of special quality. The finished product is ^{F has} the properties of a soft steel on what sits on Process for the continuous production of cold rolling and coated steel strips, according to which is to be carried out. Furthermore, in the surface coating metal silicon, aluminum, chromium, the advantageous properties emes'alloyed nickel, cobalt result , iron or an alloy of these steel, and it is an increased surface smoothness is sprayed metal on the steel strip and thus improved corrosion resistance heritage coated steel strip of a diffusion annealing aims. Due to the formation emer alloy during Difbei temperatures between 500 and 1200 ⁰ C "fusion glow liable Coating firmly_an and subject to it and then under reduction - there is no risk of detachment even with deformation.
the thickness of the coated strip by The coating metal can be expediently about 50% is cold-rolled, characterized by em in the liquid or pasty state, that gas flowing from a steel strip at high speed, such as with a carbon content below 0.2%, for example compressed air, hydrogen, Apply oxygen, stick preferably below 0.005 Ve, and a silicon substance or argon. The use of a stop below 4% / β is assumed and that the inert gas avoids oxidation of the steel-coated strip after the cold-rolling of a re-strip. Furthermore, the coating metal can kristalüsaüonserwärmung at about 700 ⁰ C currency also applied by flame spraying,
rend for a period of about 2 hours, ao Before this, the steel strip is hammered. gen will. Pickling, sandblasting, or brushing by a Shot treatment cleaned to the mechanical Adhesion of the sprayed-on coating metal too to enhance. The steel strip can be treated in this way on one or both sides and with the coating metal get splashed. The invention relates to a method for continuous- Of particular importance for the sought fine production of coated steel strips. The properties of the product are the diffusion annealing according to the coating metal silicon, aluminum. It was found that temperatures were obernium. Chromium, nickel, cobalt, iron or an Legie- 30/2 ^c about 500 C are required to the sought tion of these metals onto the steel strip sprayed quality to achieve. The annealing time depends on the coated steel strip being subjected to a diffusion annealing composition of the steel strip, its thickness, ^{the thickness of the coating and the coating at temperatures between 500 and 1200 c} C, and then reducing the metal or its peculiarity. If silicon is sprayed on as the thickness of the coated strip by about 50 ° » 35 layering metal, it is cold-rolled with a. Temperature in the range from 1000 to 1200 ⁰ C, Such a method is already known (French-worked preferably 1100-1200 ⁰ C., wherein the forensic Patent 857,779). By spraying on the annealing duration with a thickness of the steel strip> of, even coatings of even thickness 0.5 mm cannot exceed 50 hours and can be achieved in detail which, due to the diffusion annealing, adhere relatively well to the desired diffusion depth and silicon. Nevertheless, the quality of the production in the steel strip is dependent. The product essentially still could be improved, as it turned out to be complete diffusion of sprayed-on material. Silicon is particularly advantageous because a silicon content of 7 to 8% can be achieved with these layering metals and their surface properties, but in particular the coated can also be used, even if in the interest of the cold-formed steel strip even to be taken into account for the properties of the production of a steel strip with a silicon content. under 4 · / «is assumed. The invention is now based on the object. If aluminum is applied as the coating metal to further develop the known method so that an injection occurs, the diffusion annealing is preferably carried out Product of improved quality is obtained, so under a coating, for example a film from the different properties in optimal soda waterglass and at a temperature between Way at the same time is sufficient. 500 and 650 ~ C, if the aluminum is in solid contact