JPS60243225A - Manufacture of high strength stainless steel strip plate with improved surface roughness - Google Patents

Abstract

PURPOSE:To obtain the stainless steel strip having low surface roughness with good productivity by rolling by carrying out the final annealing of the stainless steel strip plate in a nonoxidizing atmosphere to limit the grain size, and then cold-rolling. CONSTITUTION:At least the final annealing of stainless steel is carried out in a nonoxidizing atmosphere to dispense with the pickling under conditions where the grain size is regulated to <=20mu, and the stainless steel is subsequently cold- rolled. High-strength stainless steel strip plate with improved surface roughness can be obtained in this way. Meanwhile, if the stainless steel wherein working-caused martensite is not generated is not used, excellent surface roughness equal to that of the rolled stainless steel can be obtained. The stainless steel plate obtained by this method has excellent surface gloss, and is smoothly plated with less detects when the surface is treated by plating, etc. Accordingly, the stainless steel is also suitably used as the substrate for a solar cell.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a high-strength stainless steel strip with improved surface roughness suitable for surface gloss materials such as solar cell substrates and decorative items, or materials to be subjected to surface treatments such as plating. Regarding manufacturing methods, materials that require surface gloss such as decorative items and materials that undergo surface treatments such as plating have traditionally required extremely low surface roughness. Furthermore, in recent years, efforts have been made to reduce the cost of amorphous silicon solar cells.

A lot of research is being done to make this a reality. Since this solar cell has a structure in which an amorphous film of only about 1 μm is formed on the substrate, the substrate has a large influence on the cell performance, cost, etc. the current.

As substrates and materials, metal substrates and glass substrates have been put into practical use, and ceramic 2-polymer resin substrates and the like are also being considered. Among these, stainless steel is the most promising industrially because it is a high-strength metal material.

Required characteristics for stainless steel substrates are: (1) The surface roughness of the substrate must be as small as Rmaxo, 2 μm or less, and be uniform over the surface of the substrate.

■ There are no protrusions on the surface of the board.

■ Minimum number of minute defects such as bits and scratches.

■ The reflectance of the substrate surface is high and the effective optical path can be utilized.

etc.

Currently, it is not possible to manufacture a product by rolling with two or more required characteristics, and it is necessary to perform mechanical polishing, surface treatment, etc. on the surface after rolling. But these mechanical polishing etc!
Loe is less productive.

Another disadvantage is that the cost is high, and converting sunlight with low energy density into electrical energy requires a large area, so it is possible to manufacture solar cells in large quantities at low cost without degrading their performance. In order to develop a possible substrate material, i.e., high-strength stainless steel with improved surface roughness through rolling process, the inventors conducted various studies on the factors that were not as good as the surface roughness of stainless steel. It was also discovered that the occurrence of deformation-induced martensite is a major hindrance. Based on these results, the present invention provides a method for producing a high-strength stainless steel strip with improved surface roughness.

In the present invention, at least the final annealing is performed in a non-oxidizing atmosphere, that is, an atmosphere that does not require pickling treatment, under conditions such that the grain size becomes 20 μm or less.

A method for manufacturing a high-strength stainless steel strip with improved surface roughness by subsequent cold rolling.

Alternatively, stainless steel that does not generate deformation-induced martensite is subjected to at least the final annealing in a non-oxidizing atmosphere, that is, an atmosphere that does not require pickling treatment, under conditions that reduce the grain size to 20μ or less, and then cold rolled. A method for producing a high-strength stainless steel strip with improved surface roughness, more preferably, the cold rolling roll is a carbide roll, the degree of rolling is 40% or more, and the surface roughness has a grain size of 15 μ or less. This is an improved method of manufacturing high strength stainless steel strip.

Next, the reason for the limitations of this patent will be explained.

The present inventors have attempted to reduce the influence of grain boundaries on surface roughness to a point where tl can be almost ignored.

It has been found that it is necessary to perform at least the final annealing in a non-oxidizing atmosphere that does not require pickling treatment so that the grain size is 20 μm or less. When pickling treatment is applied after annealing, the grain boundaries are selectively etched, so even if this material is cold rolled, the depressions at the grain boundaries remain, resulting in a surface roughness as good as that of a rolling roll. does not indicate. In addition, even if annealed in a non-oxidizing atmosphere, if the grain size exceeds 20μ, the width of the grain boundaries will become wider, and even after subsequent cold rolling, the grain boundaries will remain as depressions, so the grain size should be reduced to 20μ. It is necessary to do the following. In the case of kernels, the grain size is 15p or less.
I really like it. In addition, there is no particular restriction on the rolling roll and workability after annealing, but for high-strength materials such as stainless steel, carbide rolls are preferable because they have less roll flatness during rolling and can achieve a high workability, and the workability is 40g6. The higher degree of working is preferable because the material is closer to the roughness of the rolling roll.

4. Among stainless steels, in stainless steels that have deformation-induced martensite, deformation-induced martensite occurs within the grains, so even if the influence of grain boundaries is removed, the surface roughness will not be as good as that of a rolling roll. Therefore, it is necessary to use stainless steel in which deformation-induced martensite does not occur in terms of composition.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

・Example As shown in Table 1, 5US304 with a composition that generates deformation-induced martensite and a composition that does not generate it are cast, followed by hot rolling, cold rolling, annealing and pickling, and cold rolling. It was made to have a thickness of 0.2 m. The thus prepared sample was finally annealed in an ammonia decomposition gas atmosphere. At this time, the crystal grain size was divided into 25μ and 10μ for compositions in which deformation-induced martensite was generated, and the crystal grain size was 10μ for compositions in which deformation-induced martensite did not occur.

This annealed material was rolled using a tungsten carbide carbide roll (roll surface roughness Rmax = 0.12μ).
．． After final cold rolling to a thickness of 1M, the surface roughness of the product was measured. These results are shown in Table 1 along with comparative alloys.

As shown in Table 1, the manufacturing method of the present invention can improve the surface roughness to a point close to the limit, where there is almost no difference from the surface roughness of a mill roll. Therefore, if the surface roughness of the rolling roll is improved, the surface roughness of the product will also be improved. It will be improved. As described above, the stainless steel sheet whose surface roughness has been improved by the manufacturing method of the present invention has good surface gloss, has few defects when subjected to surface treatment such as plating, and can be plated smoothly.

Furthermore, a material suitable for use as a substrate material for solar cells can be manufactured.

Claims (1)

[Scope of Claims] (1) At least the final annealing is performed in a non-oxidizing atmosphere, that is, an atmosphere that does not require pickling treatment, under conditions such that the grain size becomes 20 μm or less. A method for manufacturing a high-strength stainless steel strip with improved surface roughness by subsequent cold rolling. (2) The method for producing a high-strength stainless steel strip with improved surface roughness according to item (1), wherein the cold rolling roll is made of carbide 1-roll. (3) Paragraphs (1) and (3) where the degree of rolling is 40 or higher;
2) A method for producing a high-strength stainless steel strip with improved surface roughness as described in section 2).・Claims (1) and (2) in which the crystal grain size is 15μ or less;
Method 6 for producing high-strength stainless steel strips as described in item (3)
A method for manufacturing a high-strength stainless steel strip with improved surface roughness by performing rolling in an atmosphere that does not require washing treatment under conditions such that the grain size becomes 20 μm or less, and then cold rolling. -゛(6) The cold rolling roll is a carbide roll (6)
A method for producing a high-strength stainless steel strip with improved surface roughness as described in . (No. (clause, (6) where the degree of rolling work is 40- or more.
) High-strength stainless steel strip with improved surface roughness. Production method. (8) Items (5) and (5) where the crystal grain size is 15μ or less.
6) A method for manufacturing a high-strength stainless steel strip with improved surface roughness as described in item (η).