JPS626716A - Rolling oil supply method for warm rolling - Google Patents

Abstract

PURPOSE:To hold a stock to be rolled at a proper temperature and to perform warm rolling with a proper lubrication by applying a rolling liquid to every rolling roll for warm rolling after the rolls are covered to proof drips in their inside, cooling the stock mainly with a spray in the outlet side, and wiping the stock to remove remaining liquid. CONSTITUTION:When a stock 1 to be rolled is warm rolled at a temperature of 100-300 deg.C by a continuous rolling mill, headers 6 and 7 provided with drip proof scrapers 4 and 5 are set in the inlet side of stands 20,30, and 40. A rolling oil 60 is applied to rolls 2 and 3. Headers 8 and 9 are set in the outlet side and the surface of a roll 23 and the stock 1 mainly are sprayed with a coolant 70 to be cooled to prevent a temperature of the stock 1 from rising. Remaining liquid on the stock 1 is removed by a side spray 10. Another remaining on the stock 1 going out of the final stand 40 is removed by a dewatering roll 11 completely. A good oil film is kept and no oil film breakdown by temperature-rise occurs, so that the surface of the stock 1 becomes good without oxidization.

Description

Detailed Description of the Invention (Field of Industrial Application) The technical content of the present invention is to ensure an appropriate supply of a rolling fluid during warm rolling of a thin plate using a continuous cold rolling mill. It is.

(Prior Art) In recent years, a warm rolling method has been attracting attention as a method for advantageously performing cold rolling. For example, JP-A-58-196102 and JP-A-196108 disclose a warm rolling method that utilizes the sensible heat of a hot rolled coil for cold rolling. When carrying out the warm rolling method, it is necessary to supply rolling oil, but the supply of rolling oil was carried out in the same manner as in the case of cold rolling. A conventional general rolling oil supply method is to spray an 8 to 7% emulsion liquid of mineral oil, beef tallow, or synthetic ester onto the roll bite surface of a rolling roll.

(Problems to be Solved by the Invention) For example, when rolling a material to be rolled at a temperature of 100°C or higher, processing heat accompanied by a temperature increase of 200°C or higher is generated in the material that has passed through the rolling rolls, and In the oil supply method, the oil film in the rolling oil breaks between the surface of the rolling roll and the material to be rolled, especially in the rear stage stand, which tends to cause seizures called heat scratches. As a result, surface flaws may occur in the material to be rolled, or the rolling rolls may be damaged, making rolling impossible.

When the temperature of the rolled material reaches 300°C or higher as described above, an oxide film is formed on the surface of the rolled material,
Adverse effects such as changes in resistance during rolling occur.

Furthermore, Japanese Patent Publication No. 58-5781 previously filed by the present applicant is known as a lubricating method capable of eliminating processing heat generated when a rolled material passes through rolling rolls. According to this lubricating method, it is possible to cool the rolled material after passing through the rolling rolls, but there is a drawback that the rolled material cannot be cooled excessively and a warm state cannot be maintained. Furthermore, since the material to be rolled passes through the next stage of rolling rolls with rolling oil unevenly adhered to it,
There is also the problem that rolling properties are inhibited, making it difficult to apply to warm rolling.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a warm rolling method in which a material to be rolled is rolled by a continuous cold rolling mill in a temperature range of 100°C or more and less than 300°C. During rolling, a rolling liquid is applied to the surface of the roll on the inlet side of the roll of each high stand under a drip-proof shield facing the material to be rolled; On the exit side, an advantageous supply of rolling oil is ensured by a combination of cooling the material to be rolled and/or the rolling rolls by spraying a coolant and wiping off residual liquid on the material to be rolled. .

In addition, the above-mentioned rolling liquid is the rolling oil or rolling oil emulsion liquid mentioned above, and drip-proof blocking can be achieved by, for example, a scraper or wiper disposed close to the outer periphery of the rolling roll. The rolling oil supply method of the present invention will be explained with reference to FIG. FIG. 1 schematically shows a continuous cold rolling mill. First, in the first stand zO, a material to be rolled l is placed on the entry side of the rolling roll 2.8.
A header 6.7 is provided above and below, and a rolling fluid (rolling oil of 15% or more, or rolling oil stock solution) 60 is sprayed from the header 6.7 onto the rolling roll 2. 2.Apply oil to 8. At the same time, rolling roll! , 8 is applied to the rolling material 1.
1 rolling roll 2 to prevent dripping, scattering and adhesion
, 81C contacting and extending in the longitudinal direction of the scraper
4 and 5 are arranged to block the connection between the rolling rolls 2 and 8 and the rolled material IK so that the rolling liquid 60 does not accrete on the rolled material IK.

Further, on the exit side of the rolling rolls 2 and 8 of the first stand 20, a header 8 is attached to the rolled material l and the rolling roll 2°a.
．． A coolant (cooling water or a low concentration rolling oil emulsion liquid) 70 is sprayed from 9 to particularly cool the rolled material 1. Then, K before the rolling roll 2.8 of the next intermediate stand 80 is bitten.

Rolling fluid attached to rolled material IK 60. and coolant 70
are wiped off with the side spray 10 to remove these residual liquids.

In the stands subsequent to the next intermediate stand 80, the operation of the first stand 20 may be repeated to carry out rolling.

On the exit side of the final stand 40, the remaining liquid may be wiped off using a side spray lO as in the upstream stand, but a draining roll 11 is provided in place of the side spray 10 to completely remove the remaining liquid. It is desirable to do so.

Furthermore, as a residual liquid treatment on the outlet side of the final stand 40,
For example, it may be configured as shown in FIG.

In this case, scrapers 12 and 18 similar to those on the input side are provided on the exit side of the rolling roll 2.8 to prevent the coolant 70 or the rolling liquid 60 from adhering to the rolled material IK. Further, the other configurations are the same as those in FIG. 1 above, and are given the same symbols and explanations will be omitted.

In the above explanation, the material to be rolled l on the outlet side of the rolling rolls 2 and 8 is cooled by spraying the rolling fluid 60 from the header 8.9. Roll coolant containing oil may be sprayed, and cooling water may be sprayed onto the rolled material 1 from a separately provided header. Furthermore, the side spray 1 on the exit side of the rolling rolls 2 and 8
0 may be replaced with a colander roll.

(Function) The inventors have described several examples of conventional rolling oil supply methods.
A comparative experiment was conducted regarding its rolling properties. The rolling oil supply methods compared here are: (1) A method of continuously supplying a large amount of an emulsion liquid with a rolling oil concentration of 8% to the roll bite surface of the rolling roll; (1) A method of applying rolling oil to the rolling roll. ω1) Method of applying emulsion liquid with rolling oil concentrations of 5%, 10%, and 20%, respectively, to the rolling roll, Ov) Rolling oil concentration No% and 15% on the inlet side of the rolling roll. This is a method of supplying an emulsion liquid having a rolling oil concentration of 5% at the outlet side.

The material to be rolled used in this experiment was a general cold rolled steel plate, the rolling speed was 3 om, p, m, and the cold rolling reduction was 50% at maximum.

First, FIG. 8 shows the results of measuring the coefficient of friction between roll strips during rolling with respect to the above rolling oil supply method.

As is clear from the figure, there are two methods: applying rolling oil 'It to the O rolling roll, applying an emulsion liquid with a rolling oil concentration of 20% to the rolling roll, and applying rolling oil with a concentration of 15% to the inlet side of the Q rolling roll. It can be seen that the method of supplying an emulsion liquid with a rolling oil concentration of 5% to the outlet side gave equivalent results, and both exhibited good rolling properties in terms of friction coefficient.

Next, the relationship between the temperature of the rolled material and the coefficient of friction is as shown in FIG. Note that the conditions of the material of the material to be rolled, the sheet passing speed, and the cold rolling reduction ratio are the same as those in the experiment shown in FIG. In addition, as a rolling oil supply method, the rolling oil concentration is 15% on the inlet side of the rolling roll.
%, an emulsion liquid with a concentration of 5% was supplied to the outlet side, and a small amount of the emulsion liquid of rolling oil was sprayed onto the rolled material on the inlet side to cool it slightly.

From Figure 4 to Figure 5, the friction coefficient is lowest when the temperature of the rolled material is 200°C to 250°C, and when it exceeds 250°C and reaches 300°C, the effect of the oxide film generated on the surface of the rolled material As a result, the variation in the coefficient of friction is rapidly increasing. Therefore, it can be seen that continuous rolling becomes impossible when the temperature of the material to be rolled reaches 300°C or higher.

From the results shown in FIGS. 3 and 4, the following was found.

(1) If a rolling liquid such as an emulsion liquid with a rolling oil concentration of 15% or more or a rolling oil stock solution is applied to the rolling roll,
Good rolling properties can be obtained.

(2) Good rolling can be achieved by keeping the temperature of the material to be rolled between 200"C and 250°C, that is, by preventing excessive cooling of the material by the rolling fluid or coolant. can.

(Example) The present invention will be explained in detail below.

General cold rolling is the material to be rolled! A thin plate with a base plate thickness of 2.8 mm was used and rolled under the following conditions to examine the rollability.

Warm conditions: Entry side temperature 150°C Rolling fluid: 15% emulsion Coolant: 8% emulsion Results By controlling the coolant so that the plate temperature is 150°C at the entry side of each stand, seizure phenomenon can be prevented. 〈It was possible to roll to the same extent as before.

(Effects of the Invention) As explained above, according to the present invention, an oil film can be formed on the rolling rolls of each stage stand, and the temperature of the rolled material at the entrance side of the rolling roll of the next stage can be maintained at an appropriate temperature. It is something that can be done. Therefore, warm rolling with appropriate lubrication can be easily performed while maintaining an optimal warm state.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing an outline of implementing the method of the present invention, Fig. 2 is an explanatory diagram showing a modification of the implementation of Fig. 1, and Fig. 8 is a diagram showing the relationship between the method of supplying rolling oil and the coefficient of friction. Graph, FIG. 4 is a graph showing the relationship between the temperature of the material to be rolled and the coefficient of friction. 1... Rolled material 2, 8... Roll roll 2
0... 1st stand 80... Intermediate stand 40
...Final stand 60...Rolling liquid 70.
... Coolant patent applicant: Kawasaki Steel Corporation Same applicant: Kyodo Yuushi Co., Ltd. Figure 1 Figure 2

Claims (1)

[Claims] 1. In warm rolling in which the material to be rolled is rolled by a continuous cold rolling mill in a temperature range of 100°C or more and less than 300°C, at the rolling roll entry side of each corrugating stand. , applying a rolling fluid to the surface of the roll under a drip-proof shield facing the material to be rolled; and applying a cooling agent to the material to be rolled and/or the rolling roll at the exit side of the rolling roll of each stage stand. A rolling oil supply method in warm rolling that combines cooling by spraying and wiping off residual liquid on the rolled material.