JPH0420595A - Lubricant for hot rolling and method for hot rolling stock steel using the lubricant - Google Patents

Abstract

PURPOSE:To obtain the title lubricant capable of improving the qualities of an inner surface of a hollow untreated steel tube and increasing the service life of a plug, for example, in the plug milling of the steel tube on a production line of seamless steel tube by selecting the title lubricant prepared by mixing a specific compound and an inorganic heat-resistant covering material. CONSTITUTION:The title lubricant which is prepared by mixing a water-soluble boron compound and an inorganic heat-resistant covering material such as water-glass is selected.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hot rolling lubricant and a method for hot rolling mi material using the lubricant.

``Conventional technology'' Conventionally, in the production line of seamless steel pipes, especially in the plug mill rolling of hollow shell tubes, graphite or graphite and salt have been mainly used to improve the quality of the inner surface of the hollow tube and extend the life of the plug. i1m lubricant is used as a component (Japanese Patent Application Laid-open No. 1983
(Refer to Japanese Patent Application Laid-open No. 14407 and Japanese Patent Application Laid-open No. 5836830).

``Problems to be Solved by the Invention'' By the way, since the lubricant mainly composed of graphite or graphite and salt is a powder, it is necessary to apply it uniformly over the entire inner circumferential surface of the hollow tube and apply it frA'41. It is difficult to do so, and the effect of improving the quality of the inner skin and the lifespan of the plug (v: gold) is small.

"Means for Solving the Problems" The hot rolling lubricant according to the present invention is intended to solve the problems of the conventional lubricants, and its first gist is that the lubricant for hot rolling is water-soluble. A lubricant for hot rolling comprising a mixture of a boron compound and an inorganic heat-resistant film forming agent.

The second gist of the present invention is a hot rolling lubricant comprising a mixture of graphite and an inorganic heat-resistant film forming agent.

A third aspect of the present invention is a hot rolling lubricant comprising a mixture of a water-soluble boron compound, graphite, and an inorganic heat-resistant film forming agent.

Moreover, the present invention uses each of the above lubricants! A method for hot rolling I materials has been developed, and the fourth aspect of the present invention is that a lubricant consisting of a water-soluble boron compound and an inorganic heat-resistant film forming agent is applied immediately before the rolling mill. and/or hot rolling the steel material while dispersing it on the steel material to be rolled and/or the rolling tool immediately after.

The fifth aspect of the present invention is to spray an ill disinfectant consisting of graphite and a heat-resistant film-forming agent on the rolling material and/or the rolling tool immediately before and/or after the rolling mill. , to hot-roll WI material.

The sixth aspect of the present invention is to apply a lubricant comprising a water-soluble boron compound, graphite, and an inorganic heat-resistant film forming agent to a rolled steel material and/or a rolling tool immediately before and/or after a rolling mill. The purpose is to hot-roll the vI4 material while dispersing it.

"Function J" According to the first aspect of the present invention, a hot rolling lubricant comprising a mixture of a water-soluble boron compound and an inorganic heat-resistant odor-forming agent is used, for example, in a production line for seamless steel pipes, especially During plug mill rolling of hollow shells, water-soluble boron compounds can be sprayed on the inner peripheral surface of the hollow shell and/or the plugs to prevent seizure between the hollow shell and the plug, and to form an inorganic heat-resistant coating. The agent improves the adhesion of the water-soluble boron compound to the entire inner circumferential surface of the hollow shell tube and/or the plug, and forms a film on the inner circumferential surface of the hollow shell tube and/or the plug to prevent oxidation of the inner circumferential surface of the hollow shell tube and/or the plug. Since the amount of scale generated can be reduced, it is possible to roll hollow tubes with good inner surface skin, and the life of the plug can be improved.

As in the second aspect of the present invention, a frA disinfectant for hot rolling made of a mixture of graphite and an inorganic heat-resistant film forming agent is applied to the inner circumferential surface of the hollow shell tube and/or the plug in the same manner as described above. By dispersing graphite, it is possible to prevent seizure between the hollow tube and the plug, and the inorganic heat-resistant film forming agent improves the adhesion of graphite to the entire inner peripheral surface of the hollow tube and/or the plug. By forming a coating on the inner circumferential surface of the hollow shell tube and/or the plug, it is possible to suppress oxidation of the inner circumferential surface of the hollow shell tube and/or the plug, and reduce the amount of scale generated, making it possible to roll the hollow shell tube with a good inner surface. At the same time, the life of the plug can be improved.

As in the third aspect of the present invention, a hot rolling lubricant made of a mixture of a water-soluble boron compound, graphite, and an inorganic heat-resistant film forming agent is applied to the inner circumferential surface of the hollow shell tube in the same manner as described above. By spraying the water-soluble boron compound and graphite on the plug, it is possible to prevent seizure between the hollow tube and the plug, and the water-soluble boron compound and graphite can be sprayed on the plug. In addition to improving adhesion to the entire inner circumferential surface of the hollow tube and/or the plug, a coating is formed on the inner circumferential surface of the hollow tube and/or the plug to suppress oxidation of the inner circumferential surface of the hollow tube and/or the plug, thereby suppressing the formation of scale. Since the amount can be reduced, it is possible to roll a hollow tube with good inner surface texture, and the life of the plug can be improved.

According to the fourth aspect of the present invention, an fR lubricant consisting of a water-soluble boron compound and an inorganic heat-resistant film forming agent is applied to a rolled steel material and/or a rolling tool immediately before and/or after a rolling mill, such as a seamless On the inner peripheral surface of a hollow raw tube and/or a plug that has just been pierced by a piercer in a steel pipe production line, and/or on the inner peripheral surface of a hollow raw tube that has been thinned and elongated with an elongator and/or a plug. By rolling the hollow shell while spraying it on the inner peripheral surface of the hollow shell and/or the plug immediately before it is rolled in a plug mill and polished by a reeler, the hollow shell and the plug are sintered. It is possible to manufacture high-quality seamless steel pipes that are free from adhesion and have a good inner surface surface with less scale generation.

As in the fifth aspect of the present invention, the frA71!1 agent consisting of graphite and an inorganic heat-resistant film forming agent is applied to the rolled n+ material and/or the rolling tool immediately before and/or immediately after the rolling mill.
For example, on the inner circumferential surface of a hollow tube immediately after being pierced with a piercer in a seamless steel tube production line and/or a plug, and/or on the inner circumferential surface of a hollow tube that has been thinned and stretched with an elongator. Or, by rolling the hollow shell while spraying it on the plug, and/or on the inner circumferential surface of the hollow shell and/or the plug just before it is rolled in a plug mill and polished with a reeler, the hollow shell and the plug are rolled. It is possible to manufacture high-quality seamless steel pipes that are free from seizing and have a good inner surface surface with less scale generation.

According to the sixth aspect of the present invention, a lubricant comprising a water-soluble boron compound, graphite, and an inorganic heat-resistant film forming agent is applied to rolled steel materials and/or rolling tools, such as joints, immediately before and/or immediately after a rolling mill. The inner circumferential surface of a hollow tube and/or a plug that has just been pierced by a piercer in a steelless tube manufacturing line, and the inner circumferential surface of a hollow tube that has been thinned and stretched by an elongator and/or a plug. By rolling the hollow shell while spraying it on the inner peripheral surface of the hollow shell and/or the plug immediately before it is rolled in a plug mill and polished with a reeler, the connection between the hollow shell and the plug is It is possible to manufacture high-quality seamless steel pipes that are free from seizure and have a good inner surface with less scale generation.

"Example" Next, an embodiment of the present invention will be described below based on FIG.

Figure 1 shows the main parts of a seamless steel pipe production line using the Mannesmann Plaque Mill method, in which a round billet I is heated in a heating furnace 2, and the heated round billet L is pierced by a piercer 3. to make a hollow shell 1a, and to the inner circumferential surface of the hollow shell 1a immediately after perforation and/or the plug, and/or to the inner circumferential surface of the hollow shell 1a which has been thinned and stretched by the elongator 4 and/or to the plug. , and/or on the inner circumferential surface and/or plug of the hollow shell 1a immediately before being rolled by the plug mill 5 and polished by the reeler 6 and/or on the plug at a flow rate of 41/min. 1a was rolled.

The lubricant used was 5w% of a water-soluble boron compound, 10w% of graphite, and 2W of water glass as an inorganic heat-resistant film forming agent.
This is a water-soluble lubricant made by mixing 0W%.

On the inner peripheral surface of the seamless steel pipe rolled as described above,
Plug flaws caused by seizure with the plug, avatar flaws caused by scale intrusion, etc., and bit flaws were hardly observed.

Note that the lubricant may be a mixture of a water-soluble boron compound and water glass, or a mixture of graphite and water glass.

Furthermore, the 7W sanitizing agent of the present invention can be used on a seamless steel pipe manufacturing line using the Mannesmann mandrel mill method or on a steel plate rolling line, and can also be used on a seamless steel pipe manufacturing line where hollow shell tubes, guide shrouds, and rolls are sintered. It can also be used to prevent sticking.

"Effects of the Invention" As described above, according to the lubricant of the present invention and the rolling method using the lubricant, for example, in plug mill rolling of a hollow shell in a seamless steel pipe production line, the inner peripheral surface of the hollow shell In addition to improving the adhesion of the lubricant to the entire body and/or the plug, a film is formed on the inner circumferential surface of the hollow shell tube and/or the plug to suppress oxidation of the inner circumferential surface of the hollow shell tube and/or the plug, and reduce the amount of scale generated. As a result, it is possible to manufacture high-quality seamless steel pipes with a good inner surface, and the life of the plug can be improved.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram showing an embodiment of the method of the present invention. 1... Round billet 1a... Hollow tube 2... Heating furnace 3... Piercer 4... Elongator 5... Plug mill 6... Reeler - Fig. 1

Claims (6)

[Claims] (1) A hot rolling lubricant comprising a mixture of a water-soluble boron compound and an inorganic heat-resistant film forming agent. (2) A hot rolling lubricant made by mixing graphite and an inorganic heat-resistant film forming agent. (3) A hot rolling lubricant made by mixing a water-soluble boron compound, graphite, and an inorganic heat-resistant film forming agent. (4) Hot rolling the steel material while spraying a lubricant consisting of a water-soluble boron compound and an inorganic heat-resistant film forming agent onto the steel material to be rolled and/or the rolling tool immediately before and/or after the rolling mill. A method for hot rolling steel materials, characterized by: (5) The steel material is hot rolled while a lubricant consisting of graphite and an inorganic heat-resistant film-forming agent is sprinkled onto the steel material to be rolled and/or the rolling tool immediately before and/or after the rolling mill. A hot rolling method for steel materials. (6) While spraying a lubricant consisting of a water-soluble boron compound, graphite, and an inorganic heat-resistant film forming agent onto the rolled steel material and/or rolling tool immediately before and/or after the rolling mill, the steel material is hot-rolled. A method for hot rolling steel materials, which is characterized by rolling.