JPS6326362A - Production of dull roll for rolling and apparatus for forming hard surface layer - Google Patents

Abstract

PURPOSE:To obtain a hard surface layer having high hardness and wear resistance by projecting laser beams on the surface of a roll for rolling to provide a dull finish to the surface of the roll and by implanting ionized particles into the surface of the roll at high speed. CONSTITUTION:Laser beams are projected on the surface of a roll for rolling to provide a dull finish to the surface of the roll and ionized high-speed particles are implanted into the surface of the roll. Thus, a dull roll for rolling having high hardness and wear resistance is obtd. The surface roughness of the roll is hardly reduced even after use for a long time.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a method for producing a dull roll for rolling and a hard surface layer forming device, and in particular, to a method for manufacturing a dull roll for rolling and a device for forming a hard surface layer. The objective is to advantageously improve surface hardness and wear resistance.

(Prior art) Surface qualities required for cold-rolled steel sheets include adhesion of paint films and enamel, press workability, corrosion resistance, and gloss. Roughness has an important influence.

A general method for obtaining a metal surface with a desired surface roughness according to these characteristics is to dull the surface of a rolling roll such as a cold rolling roll or a temper rolling roll to the desired roughness. This is a method in which the steel plate is rolled at a predetermined pressure using this dull roll, and the roughness of the roll surface is transferred to the steel plate surface.

By the way, methods for roughening the above-mentioned cold rolling rolls and temper rolling rolls include shot blasting and electrical discharge machining.

The former shot blasting method is very simple and has the advantage of work-hardening the roll surface and improving the wear resistance of the roll, but on the other hand,
Disadvantages include that the surface roughness is irregular, hard rolls require a long time to process, and it is difficult to create deep roughness.

On the other hand, in the latter electric discharge machining method, the roughness of the roll surface is controlled by changing the applied voltage and frequency between the rotating roll and the electrode moving in the axial direction of the roll, but this does not determine the size of the crater. The range covered by the sparks is determined by the shape and dimensions of the electrode, so it is difficult to obtain a small roughness with a fine pitch.Also, the protrusions produced by electrical discharge machining are mechanically weak, so they may cause initial wear of the rolls during rolling. is intense,
Furthermore, there is a problem in that the roughness of the surface of the transferred plate changes significantly.

In addition, a method has recently been proposed in which the surface of the C roll is dull-finished by irradiating it with a laser beam (Japanese Unexamined Patent Publication No. 56-16
0892, JP 58-25557, JP 54-61043, JP 55-94790).

As shown in FIG. 1, this method irradiates the surface of the roll 1 with a laser beam emitted from a laser oscillator 3 via a plurality of mirrors while the roll 1 is supported and rotated by a roll rotation support device 2. This is a method of dull finishing the roll surface by moving the laser irradiation head 4 in the axial direction of the roll 1.

(Problems to be Solved by the Invention) However, rolling rolls subjected to dull finishing using a laser beam as described above suffer from considerable initial wear of the rolls, leaving problems that cannot be achieved satisfactorily. Ta.

The present invention advantageously solves the above-mentioned problems, and effectively modifies the dull finish surface produced by the laser beam, so that even after long-term use, the roughness of the roll surface is reduced to a minimum, thus making it desirable for steel sheets. The purpose of the present invention is to propose a method for manufacturing a dull roll for rolling that has high hardness and excellent wear resistance, which can provide a surface roughness of

(Means for Solving the Problem) In order to find out why the surface of a roll subjected to laser dulling has large initial wear, the inventors cut the roll into rounds and developed a cross-section near the surface. The weave and hardness distribution were investigated.

As a result, it was found that retained austenite, which is softer than the base material, exists on the surface of the laser dull finished roll very close to the surface of the convex portions, and therefore good wear resistance cannot be obtained.

In order to solve the above problem, the inventors conducted intensive research and found that it was possible to inject N, Ti, (1,r, etc.) ions into the laser dulled surface by ion implantation. We have found that this method is extremely effective in achieving our goals.

This invention is based on the above knowledge.

That is, in this invention, after irradiating the surface of a rolling roll with a laser beam to give the roll surface a dull finish, ionized particles are removed by ion implantation.
This is a method for manufacturing a dull roll for rolling (first invention), which is characterized by injecting into the roll surface at high speed to form a hard surface layer having high hardness and high wear resistance.

In addition, this invention irradiates the surface of the rolling roll with a laser beam to give the roll surface a dull finish, and then ionizes some of the neutral particles generated by sputtering.
A rolling process characterized by ion implantation, in which ionized particles are injected onto the roll surface at high speed while entrained with non-ionized neutral particles to form a hard surface layer with high hardness and high wear resistance. This is a manufacturing method (second invention) for a dull roll.

Furthermore, the present invention provides a vapor deposition apparatus including an ion generation source, an accelerating member for generated ions, and a target material sputtered by the ions, in which ionized particles in the sputtered particles are placed between the target material and a dull roll of the material to be processed. This is a surface hard layer forming apparatus (third invention) for a dull roll for rolling, characterized in that an acceleration electrode for accelerating is disposed.

The experimental results that formed the basis of this invention will be explained below.

First, using the roll surface roughening processing apparatus using a laser beam shown in FIG. 1 above, dull processing was performed in the following manner.

While the rolling roll 1 is rotated at a predetermined speed by the roll rotation support device 2, a laser beam emitted from a laser beam oscillator 3 is focused on the roll surface via a plurality of mirrors, and the laser beam is narrowed down. The laser irradiation head 4 rotates the drive screw 50 times in synchronization with the roll rotation.
While the roll was moving in the axial direction, the roll surface was irradiated with a pulsed laser beam to give the roll surface a dull finish.

Note that the surface roughness pattern and depth of the roll surface can be adjusted as appropriate by the frequency of the pulse, the rotational speed of the roll, and the moving speed of the laser irradiation head.

Next, the surface of the dull-finished roll thus obtained was injected with 200 kN ions by ion implantation.
A hard layer is formed on the surface layer by injection at eV. When rolling was carried out using such a roll, it was found that 1.5
It is now possible to process up to twice as much water, and the effect of wear resistance is noticeable.

Further, on the surface of the dull finishing roll described above, C and R ions, which are partially ionized from Cr particles generated by sputtering using a Cr plate as a target material and meter ions as sputter ions, are applied to the surface of the dull finishing roll at a potential difference of 10,000 V. By accelerating the process with The lifespan of the rolls has been approximately doubled.

In the above example, the roll surface is made of C, which has high hardness and wear resistance.
This is the case where a coating of each metal or an alloy of these metals can be formed in the same way, and if a metal with high hardness and wear resistance such as Ti or W is used as a target. It is possible to have ions implanted into the roll surface.

Further, by mixing nitrogen gas and oxygen gas in the inert gas, metal ions can be incident on the roll surface, and a film of metal nitride or oxide can also be formed on the roll surface.

FIG. 2 schematically shows an apparatus suitable for forming the above hard surface layer.

In the figure, number 6 is an ionization chamber, and number 7 is a magnet for increasing ionization efficiency, and both constitute an ion generation source. 8 is an accelerating electrode for extracting generated ions;
9 is a sputtering target, 10 is a hot filament for ionizing sputtered particles, 11 is a grid, and 12 is an acceleration electrode for accelerating ions. Note that 13 is a dull roll which is a material to be processed, 14 is a beam for sputtering, and 15 is a stream of sputtered particles.

In the place shown in FIG. 2, in the ion chamber 6, due to electric discharge in the magnetic field formed by the magnet 7,
For example, a rare gas is efficiently ionized and then extracted at high speed by the accelerating electrode 8. When the rare gas ion beam 14 for sputtering collides with the target 9, a particle stream 15 of the components of the target 9 is formed from the target 9 due to the sputtering effect.

After the sputtered particle stream 15 is partially ionized by the thermionic emission filament 10, it passes through the grid 11 and accelerating electrode 12 for accelerating the ionized particles, and then passes through the grid 11 and the acceleration electrode 12 to accelerate the particles at high speed while entraining non-ionized particles. Then, it is injected into the roll 8.

(Function) According to the second invention, vapor deposition and ion implantation can be performed simultaneously by simultaneously irradiating ionized high-speed particles and neutral low-speed particles onto the roll surface. For example, ion beam mixing method ( It is possible to obtain adhesion strength that is comparable to methods for increasing adhesion strength such as Niji D method), and it is also possible to extend the life of the roll because the thickness of the hard layer can be made thicker than when using only ion implantation. .

Another major difference from the IVD method is that in the TVD method, the components of ions and deposited particles are completely different, whereas in the method according to this invention, the components of ions and neutral particles are the same, so that internal defects in the film are eliminated. There is a big advantage of being small.

(Effects of the Invention) Thus, according to the present invention, even for a rolling roll whose surface has been dull-finished by a laser beam, the surface hardness of the roll can be significantly increased by subsequently forming a hard layer by ion implantation. In this way, the desired roughness of the roll surface can be maintained for a long period of time, and wear resistance is also improved, which in turn effectively contributes to extending the life of the roll.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a roll surface roughening processing device using a laser beam, and FIG. 2 is a schematic diagram of a surface hard layer forming device according to the present invention. ■... Roll 2... Roll rotation support device 3... Laser oscillator 4... Laser irradiation head 5... Drive screw 6... Ionization chamber 7... Magnet 8... Accelerating electrode 9・
...Target 10...Hot filament 11
... Grid 12 ... Acceleration electrode 13.
... Dull roll 14 ... Sputtering beam 15 ... Sputtered particle flow Figure 2 Procedures Correction September 1, 1986

Claims (1)

[Claims] 1. After dulling the roll surface by irradiating the surface of the rolling roll with a laser beam, ionized particles are injected into the roll surface at high speed by ion implantation to achieve high hardness. A method for manufacturing a dull roll for rolling, characterized by forming a hard surface layer with high wear resistance. 2. After irradiating the surface of the rolling roll with a laser beam to give the roll surface a dull finish, some of the neutral particles generated by sputtering are ionized, and then the ionized particles are processed by ion implantation.
A method for manufacturing a dull roll for rolling, characterized by injecting nonionized neutral particles into the roll surface at high speed while entraining them to form a hard surface layer having high hardness and excellent wear resistance. 3. In a vapor deposition apparatus equipped with an ion generation source, a member for accelerating generated ions, and a target material to be sputtered by the ions, ionized particles in the sputtered particles are accelerated between the target material and a dull roll of the material to be processed. A device for forming a hard surface layer on a dull roll for rolling, characterized in that an acceleration electrode is provided.