JP2505842Y2 - Roll for cold rolling - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roll for cold rolling, which relates to prevention of a flaw on a shaft (hereinafter referred to as a journal portion) of a bearing mounting portion for a roll of the roll and improvement of wear resistance.

[0002]

2. Description of the Related Art Conventionally, the journal portion of a cold rolling roll has been subjected to a hardening and quenching treatment (Hv285-327) to prevent wear due to bearing contact during rolling rotation.
However, with the recent increase in rolling operations, the frequency of roll replacement and re-grinding of the roll body has increased, and in addition to preventing wear due to bearing contact, scratches due to the work of attaching and detaching the bearing box during roll replacement and foreign material damage There has been a new demand for countermeasures against defects. Such a flaw in the journal portion not only hinders the smooth rotation of the cold rolling roll during the rolling operation, but also interferes with the attachment / detachment of the bearing box attached to the relevant portion, which makes the replacement work extremely difficult. There was a problem.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and to prevent the occurrence of flaws in the journal portion of a cold rolling roll and to improve wear resistance.

[0004]

In order to achieve the above object, the present invention employs the following means. That is, the cold rolling roll is such that the surface of the journal portion is plated with chromium.

[0005]

EXAMPLES The present invention will be described in detail below based on examples. FIG.
[Fig. 3] is an explanatory view of a main part showing an example of an inter-example rolling roll, in which 1 is a roll barrel part, 2 is a roll shaft part, 3 is a journal part, and 4 is a bearing box.

The present invention is one in which the journal portion 3 of FIG. 1 is plated with chrome, and this roll of the present invention is compared with that of the conventional hardening and quenching treatment, and the results are shown in Table 1. At this time, the roll of the present invention was plated with 10 μm of chrome.

[0007]

[Table 1]

As shown in Table 1, the conventional hardening and quenching treatment is 5
Rmax50 already in the journal after changing rolls about once
Although scratches of about 0 μm were generated, no scratches were found at the journal portion of the present invention which was plated with chrome of 10 μm, and it is clear that a great effect can be obtained in preventing scratches and improving wear resistance. .

As an example of the composition of the chromium plating bath, a gentic bath was used in which chromic acid was 250 g / l, sulfuric acid was 2.5 g / l, the temperature was 50 ° C., and the current density was 30 A / dm ² . The hardness of chrome plating varies to some extent depending on the composition of the plating bath and the plating conditions, but if possible, hard chrome plating of Hv 1000 is desirable. The thickness of the chrome plating is preferably 1 to 1000 μm from the characteristics of the chrome plating film, and most preferably 5 to 100 μm.

[0010]

As described above, according to the present invention, since the journal portion of the cold rolling roll is chromium-plated with a coating characteristic of a small friction coefficient and a high hardness, the portion is concerned. It is possible to prevent the occurrence of flaws in some places and to improve wear resistance. Further, it becomes possible to smoothly rotate the rolls for cold rolling during the rolling operation, and it is possible to eliminate the drawbacks that the desorption of the bearings is hindered.

[Brief description of drawings]

FIG. 1 is an explanatory view of essential parts showing an example of a cold rolling roll.

[Explanation of symbols]

 1 Roll body 2 Roll shaft 3 Journal 4 Bearing box

Claims (1)

(57) [Scope of utility model registration request] 1. A roll for cold rolling, characterized in that the surface of a shaft portion for mounting a rotating bearing is plated with chromium.