JPS60196207A - Two-layer plated cold rolling roll - Google Patents

Abstract

PURPOSE:To provide a titled rolling roll having excellent resistance to wear and exfoliation by providing a nickel plating layer having an adequate thickness on a roll base body and further a chrome plating layer thereon. CONSTITUTION:A nickel plating layer 2 having relatively low hardness and high adhesion strength is formed to >=10mum thickness on a roll base body 1 and further a chrome plating layer 3 having high hardness is formed thereon to >=10mum thickness. The total thickness of both plating layers 2, 3 is made 20- 100mum. The resistance to wear is improved by the layer 3 and the resitance to impact is improved by the layer 2. The two-layer plated cold rolling roll which prevents exfoliation of the layer 2 is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention relates to cold rolling rolls, and particularly to cold rolling rolls having improved wear resistance by providing a plating layer on the surface thereof.

(Prior Art) For example, cold rolling rolls used for cold rolling steel strips are required to have excellent wear resistance because of the necessity of rolling at high speed and with a high reduction ratio. In general, wear-resistant rolls include, for example, 1. ] 1li4r I:'-ru, which increased the mu content from 1 to 3% to 15 to 20%.
There are rolls containing (2) which are improved in wear resistance by forming (2) carbides, Cr-plated rolls where the surface of the finished roll is chromium plated, and rolls which are subjected to electrical discharge dulling. There are also rolls coated with thermal sprayed or sintered alloys.

However, all of these conventional wear-resistant rolls either do not have sufficient wear resistance for cold rolling, or when used as cold rolling rolls, scratches occur on the surface of the steel strip, or the required flatness cannot be obtained. However, there were problems such as being unsuitable for cold rolling or being expensive, and were not always satisfactory.

In particular, Cr-plated rolls are conventional wear-resistant rolls that have been used for the purpose of improving wear resistance. Satisfactory results have been obtained, and in the case of rolling general mild steel strips, when the rolling reduction is around 1% and the rolling load is around 500 tons, the wear resistance is improved 3 to 4 times that of ordinary forged steel rolls. It is reported that. However, in cold rolling performed with 7-fold reduction, for example, in the case of rolling of general mild steel strips and knobs, the reduction rate is 60
~90%, m1000~1500) before rolling,
At that time, the wear resistance is only 1.
It was about 5 to 2.0 degrees, which was not necessarily satisfactory considering the cost of the plating process.

Moreover, a major drawback of the Cr-plated roll is the problem of peeling of the plating layer. In other words, conventionally, the thickness of the chrome plating layer was approximately 1 ol Im, but this is 5/J nl! 'II
After I, the abrasion resistant paper was hardly exhibited, while 1
When the thickness is around 5/7 m, plating peeling occurs frequently, so considering the problems of 111it abrasion and peeling of the plating layer, a thicker metal layer of about 0 μm was used for 11"l". Adopted 'ζ and 42. However, when such a Cr-plated roll is used as a cold rolling roll under heavy pressure (31, .) mentioned in -4-1, peeling of the plating layer cannot be avoided, especially when cold rolling. Ugotote treated steel strike 'J
The deterioration of the surface quality of the knob was fatal to the GJ.

Here, due to the 1A quality change of the material to be rolled at the abutment, there is a change in the quality of the material to be rolled. Further improvement of productivity by rolling is aimed at.

(Object of the invention) The object of the invention is to provide a wear-resistant roll suitable for cold rolling.

Another object of the present invention is to provide a chrome-plated L:I-le that is suitable for cold rolling and has further improved wear resistance.

Yet another object of the present invention is to innovate a cold rolled chrome plated roll with further improved wear resistance.

(Summary of the Invention) In order to develop a hard-wearing cold rolling roll that satisfies the current L1 requirements as described above, the present inventors conducted various tests and tests.
After 1, the 111-mumenoki 1 call was found to have good compatibility with the steel slip surface and the lip surface.
After continuing research on J-Sit3+, we have completed a chrome-plated r-coal for cold rolling that not only shows excellent wear resistance even under high loads, but also has no problem with peeling of the plating layer.

That is, the present invention includes a Japanese agate layer with a thickness of 10 μm or more and a chromium plating layer provided thereon with a thickness of 10 tt n+ or more, and the combined JIJ! It is a two-layer plated cold rolling roll with a width of 20 to 100 μm.

Zunawara, dud! ll (If you have any problems, firstly, use Kel plating (micro-Vickers hardness 11ν250-400) which has a high adhesion force and is not relatively hard.
In addition, a high hardness Cr plating (micro-Vickers hardness 11ν1000 to +200) was applied to the opening of the second layer. With such two-layer plating, even if the Cr plating layer thickness is increased to 15 μml, it will not peel off.
Rather, the wear resistance is dramatically improved due to the thicker Cr plating. Furthermore, regarding impact resistance, a low hardness Ni metal layer is applied between the rolled L'J-ru base and the leaf and key layers, which absorbs the impact caused by abnormal loads. Therefore, there is no problem of the plating layer peeling off due to impact. Second, since the adhesive strength of the gel plating layer is strong, the abrasion resistance is significantly improved. It's made of 7-layer, 7-layer coating, and there are no problems in terms of thermal conductivity.

(Aspects of the Invention) The accompanying drawing (1J) schematically shows a part of the surface cross section of the cold rolling roll according to the present invention. Two-layer plating is applied to the roll base 1''-9 for inter-rolling, in which the Nino gel layer 2 and the chrome plating layer 3 are provided in this order. -J'ru no 14, if it is thinner than this, the wear resistance will not be sufficient.Also, the thickness of the nickel saw layer should be 10.+1m or more. This is because it is not sufficient to prevent the chrome plating layer from peeling off.

Here, the reason why the gold side of both plating layers is set to 20 to 100 pm is because a predetermined plating thickness is required in order for both N1), Ki, and Cr plating to achieve the desired effect. Because there is.

However, increasing the thickness of chrome plating without limit is not a good idea in terms of the plating processing cost and the cost required for roll grinding, and if it becomes too thick, the thermal conductivity will deteriorate,
This is not preferable because ranks are likely to occur. In the present invention, 1
00 μm is defined as the −L limit.

In addition, the total thickness of both layers is 20 to 1.00) Im
Therefore, both plating layers each have a thickness of 10 to 90 μn.
It will take a value within the range of 1. However, the thickness of the gold side of both the outer and outer layers does not exceed 20 to 100 μm.

Here, the rill used in the present invention is not limited to Jl and 'l' in terms of its shape, composition, and processing history. Examples of the material include hardened forged steel rolls, cast iron rolls, and high-speed tool steel rolls. From the standpoint of use, the cold rolling roll according to the present invention includes not only rolls for cold rolling under heavy rolling, but also rolls for cold rolling 81i and I quality rolling under light rolling. Even under light pressure, a significantly different effect can be obtained compared to the conventional glue 11 Mumenokirol.

Incidentally, the plating process itself may be performed using a conventional method, and no special explanation is required. Furthermore, it will be apparent to those skilled in the art from the foregoing description that the present invention is not limited to such plating operations. In order to avoid the formation of an alloy ratio phase between the plated layers or with the substrate, it is preferable to avoid tacking treatment after plating.

The invention will now be further described in connection with embodiments thereof.

Example 1 The surface of a cold rolling roll was plated with 60 μm IV Ni, and then plated with 40 μm Cr.

When the rolling roll obtained in this way was used as a cold rolling Kundem mill #1 stun 10-ru, the roll life was about 5 to 10 times that of conventional forged steel 1-ru under the same conditions. In addition to improved elongation and abrasion resistance, the #1 stand's gripping properties also improved, and the Mill 11 resistance improved. There were no problems with peeling off the plating.

In the case of Naori ROM single-layer plated rolls, the roll life was only extended by about 1.5 to 2.0 degrees compared to conventional forged steel rolls. You can see if you can get the desired effect.

Example 2 In this example, the surface of the roll for cold pass rolling is 1.5. +1m
A thick Ni plating was applied, and then a 20 μn1 thick Cr plating was applied thereon.

When temper rolling was performed using the two-layer steel roll obtained in this way, the roll life was extended by about 10 to 20 times under the same conditions compared to conventional forged steel 1-roll, and the number of roll changes was reduced. As a result, it became possible to increase the rolling amount. Also,
Many advantages were seen, such as the roll consumption rate being reduced to 1/10 and width schedule-free rolling possible.

In addition, in the case of single-layer chrome plating, the lifespan could only be extended by 3 to 4 times compared to conventional forged steel rolls.
It can be seen that the effects of the present invention as described above are remarkable.

Thus, despite its simple configuration, the present invention has significant practical effects and greatly contributes to this field.

[Brief explanation of the drawing]

The drawing is a schematic cross-sectional view of the surface of a cold rolling roll according to the present invention. 1: Roll base 2; Nickel plating layer 3: Chrome plating layer Applicant Sumitomo Metal Industries Co., Ltd. Agent Patent attorney Akira Hirose −

Claims (1)

[Claims] A two-layer plated cold rolling roll comprising a nickel plating layer with a thickness of 10 μm or more and a chromium plating layer with a thickness of 10 μm or more provided thereon, the total thickness of both plating layers being 20 to 100 μm.