摘要:
The invention relates to a method for hot-dip coating a metal strip, in particular a steel strip, in a molten metal bath (3), according to which the metal strip (1) to be coated is heated in a continuous furnace (2) and introduced into the molten bath (3) through a pipe (6) which is connected to the continuous furnace and submerged in said molten bath. In order to fulfil the requirements for the coated strip (1) in terms of good deformation behaviour of the strip with the lowest possible degree of cracking or peeling and also in terms of a high degree of anti-corrosion protection in an improved and at the same time reliable manner, the invention proposes that in the region delimited by the pipe (6) a melt is used with a chemical composition that is or will be deliberately adjusted to be different from the chemical composition of the melt used in the molten bath (3).
摘要:
The invention relates to a flat product made of metal material, in particular a steel material, an advantageous use and a roll particularly suitable for producing such a flat product, and a method for producing such flat products. In order that the flat product, in particular thin metal sheet, exhibits improved tribological properties and provides very good preconditions for a paint coating, which also has an excellent appearance even in the case of a lower overall layer thickness of the paint structure in the finally painted state, it has been provided with a deterministic surface structure which has multiple depressions which have a depth in the range from 2 to 14 μm, wherein the depressions are designed to be I-shaped, H-shaped, cross-shaped, C-shaped or X-shaped, and wherein the surface structure is characterized by a peak index RPc in the range from 45 to 180 1/cm, an arithmetic mean roughness Ra in the range from 0.3 to 3.6 µm, and an arithmetic mean waviness Wsa in the range from 0.05 to 0.5 µm. A roll according to the invention which is particularly suitable for producing such a flat product has been textured by means of a short-pulse laser process and has a deterministic surface structure which has multiple overlapping cells which are arranged in such a way that they delimit double-I-shaped, H-shaped, cross-shaped, C-shaped or X-shaped material structures in the roll surface, and wherein the surface structure of the roll, measured in the roll axial direction, is characterized by a peak index RPc in the range from 80 to 180 1/cm, an arithmetic mean roughness Ra in the range from 2.5 to 3.5 µm, and an arithmetic mean waviness Wsa in the range from 0.08 to 1.0 µm.
摘要:
The invention relates to a metal flat product, preferably consisting of steel, with a surface improved by hot-dip coating, said product having a metal alloy coat (11) and a metal top coat (12') lying thereon, the chemical compositions of said coats differing from each other. Both coats (11, 12') are produced in one process step and define a continuous transition region (13), in which there is a mixture of the two differing chemical compositions. The alloy coating (11) has a thickness of less than 8 μm, preferably less than 6 μm and the top coat (12') is formed from aluminium or zinc. The product is characterised in that the top coat (12') is substantially devoid of silicon and has a thickness of more than 4 μm, preferably more than 5 μm. The flat product according to the invention is characterised by an improved coating which allows said product to fulfil the requirements in terms of good deformation properties and at the same time a high degree of anti-corrosion protection in an improved manner.
摘要:
The present invention relates to a method for producing a component from a steel product coated with an Al-Si protective coating, and to an intermediate product, which is generated in the course of such a method and can be used for the production of components of the type in question. In the course of the method, the steel product coated with the Al-Si coating is subjected to a first heating step, wherein the temperature and the duration of the heat treatment are set such that the Al-Si coating is only partially pre-alloyed with Fe of the steel product, in a second heating step the steel product is heated to a heating temperature above the Ac1 temperature, the steel product at said heating temperature having an at least partially austenitic structure, wherein the temperature and duration of the second heating step are set such that the Al-Si coating in the course of the second heating step is completely alloyed with Fe of the steel product, the steel product heated to the heating temperature is shaped into the component, and the resulting component is cooled in a controlled manner in order to produce a hardness structure.
摘要:
The invention relates to a flat steel product, having an optimal deformability and a further improved behaviour during a cold forming in a cold-forming tool. In this way, a flat steel product according to the invention has a steel substrate and a protective coating which is applied to the steel substrate via hot-dip coating and generated via a subsequent galvannealing treatment, and the main component of which is zinc, wherein the protective coating has pores on the free surface thereof extending into the protective coating. According to the invention, a flat steel product of this type is characterised in that the numbers of right-skewed measurement tracks determined in a topographical evaluation outweighs the number of non-right-skewed measurement tracks, both in the measurement direction and transverse to the measurement direction, wherein the right-skewed measurement tracks are determined in that: a respective measurement value collective of respectively at least 10,000 measurement values is detected from a square surface section with an edge length of 1 mm for at least 400 parallel measurement tracks; the mean value and the median are determined for each of the detected measurement value collectives in the measurement direction and transverse to the measurement direction; for each measurement track, the mean value determined therefor is compared with the median determined for same; and the measurement tracks in which the mean value is greater than the median are categorised as right-skewed.