JPH03121197A - Lubricant provided with function of preventing oxidation of high-temperature metal surface - Google Patents

Abstract

PURPOSE:To obtain a lubricant provided with functions of both lubrication and preventing oxidation of a high-temperature molten metal surface by mixing a vegetable or mineral oil with a tetrafluoroethylene resin so as to disperse the resin in the oil to form a colloid. CONSTITUTION:A lubricant which contains at least one oil selected from a vegetable oil, such as rapeseed oil or soybean oil, and a mineral oil, such as liquid paraffin or mineral oil, and 1-20wt.%, based on total weight, tetrafluoroethylene resin dispersed in the oil to form a colloid. This lubricant can be used for all kinds of processing, e.g. casting of iron, iron alloy, stainless steel, aluminum, aluminum alloy, copper, etc. Particularly in, e.g. casting of iron, a tetrafluoroethylene resin alone cannot perform a lubricating action in some cases. In those cases, boron nitride may be added thereto. Since the use of a lubricant having boron nitride incorporated therein can improve the mold release properties of metal, boron nitride can be employed as a component of a lubricant for processing, such as casting, of all kinds of metals.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application: The present invention relates to a lubricant that has the function of lubricating the surface of high-temperature molten metal and preventing oxidation in continuous metal casting.

Problems to be solved by the invention: Conventional metal precision casting methods, die casting methods, hot casting methods,
In the light alloy casting method, extrusion method, ingot method, and continuous casting method, various types of powdered graphite, vegetable oil, mineral oil, silicone oil, etc. are used alone or as a mixture as lubricants, but they do not cause oxidation of the high temperature metal surface. cannot be completely avoided. When oxidation occurs on the metal surface, skin, scratches, etc. occur on the metal surface. Conventionally, in order to prevent such oxidation of the metal surface, inert gas such as argon nitrogen has been blown onto the high temperature metal surface. However, blowing an inert gas has the disadvantage that the molten metal itself is cooled, and the inert gas itself is expensive.

Means for Solving the Problems: The present invention uses at least one oil selected from the group consisting of vegetable oils such as rapeseed oil and soybean oil, and mineral oils such as liquid paraffin oil and mineral oil, which have been conventionally used as lubricants. Tetrafluoroethylene resin C (hereinafter referred to as PTFE) or P
It was discovered that a lubricant obtained by adding TFE and boron nitride (hereinafter referred to as NB) in an amount of 1 to 20% by weight based on the total weight has a lubricating function and a function of preventing metal oxidation. It's arrived. The PTFE and NB are colloidally dispersed in the oil. Sodium, potassium or lithium salts of stearic acid and the like may also be used as lubricating aids.

NB has excellent heat resistance, high-temperature lubricity, high temperature, lubrication with the surface of molten steel, and mold release property. PTFE has excellent heat resistance, lubrication, and mold release property, and forms gas when it comes into contact with high temperature and molten steel surface. The strong ionic reduction reaction of carbon tetrafluoride (CF4) prevents the generation of scum, prevents the primary surface oxidation that occurs during the formation of a solidified shell, and maintains a non-oxidizing atmosphere inside the mold and hood to produce high-temperature, molten metal interface slabs. Actively prevents surface oxidation. In other words, by covering this metallurgical mechanism with the above-mentioned lubricating pace oil, a high-temperature active lubricant is achieved by continuously supplying lubricating oil to the mold and caster using a normal oiler mechanism, and high-grade precision cast slabs are mass-produced. I can do it. The effect is remarkable and unrivaled. Furthermore, numerical thermal decomposition is an endothermic reaction (nitrogen seal), whereas this high temperature active lubricant is an exothermic reaction (rPTFE)
1,000 cat/g) has a heat retention effect and can cover casting failures caused by temperature drops such as stream stagnation and discontinuity. Regarding safety, this high-temperature active lubricant has a maximum PTFE content of 10 wt% or less, and contains a trace amount of H in the oil mist.
Since F is adsorbed and diffused, natural ventilation is sufficient.

The lubricant of the present invention can be used as a lubricant for all types of processing such as casting of iron, iron alloys, stainless steel, aluminum, aluminum alloys, copper, etc. Particularly in iron casting, etc., PTFE alone may not provide the lubricating effect. In this case NB is added.

When a lubricating oil containing NB is used, metals have good mold release properties, so NB can be used as one of the lubricant components in processing such as casting of all kinds of metals.

Composition example 1 Base oil additive Additive rapeseed oil 90wt PTFE powder 4 NB powder 2 // Lithium stearate 1 Organic amide 3wt% (dispersant) Composition example 2 Base oil additive Additive Composition example 3 Base oil additive Additive rapeseed oil PTFE powder NB Powder lithium stearate Organic amide Liquid paraffin PTFE powder NB Powder lithium stearate 83wt 8 〃 3 〃 1 〃 5 〃 90wt 4 〃 2 〃 1 〃 Composition example 4 Base oil additive additive composition example 5 Base oil Base oil additive Additive composition example 6 Base oil additive Organic amide Liquid paraffin PTFF powder NB Powder lithium stearate Organic amide Rapeseed oil Liquid paraffin PTFE powder NB Powder stearate Organic amide Rapeseed oil PTFE powder Lithium stearate Organic amide 3wt% 83wt CH8 〃 3 〃 l 〃 5 〃 92wt CH43 〃 6 〃 3 〃 1 〃 4 〃 92wt CH4 〃 1 〃 3 〃 Composition example 7 Base oil additive Liquid paraffin PTFE powder Lithium stearate organic amide 88w tchi 8 〃 1 〃 3 〃 Composition example 8 Base oil Rapeseed oil 45wt Chi-base oil
Liquid paraffin 45 Additive PTFE powder 6 Lithium stearate 1
〃Organic amide 3 // Example 1 Conventionally, refined rapeseed oil, vegetable oil, mineral oil, single substance, and composite oil were supplied into the lubricant supply ring from all sides of the top of a rectangular mold lined with copper plates using the continuous casting method, and the surface of the steel billet slab was lubricated and released. Due to mold and oxidation complexes, the skin is rough, subcutaneous blow poles, and pockmarks, and wrinkles at the edges of blums and slabs are caused by oxidation exposure, especially at the corners.The overall oxidation of the steel slab causes poor yields (also, the lubrication and mold release of the molded copper plate lining are not good, so the lifespan is shortened) The rotation rate is getting worse.The present invention provides good lubrication, mold release, non-oxidizing agent, composition example 1, 2.6.8 A steel billet that is supplied into a lubrication supply ring under the same conditions as the conventional method. Observation of the surface of the slab revealed that it was smooth with no roughness and was in an oxidized state.The corners, which are particularly prone to problems, were smooth and maintained a metallic luster.Especially in Example 2, the overall condition was good.The overall yield was the same. Improved by about 3 inches.

Practical example 2 Automatic pouring into aluminum and aluminum alloy die casting molds Conventional lubrication, using oil-soluble as a mold release agent, graphite, water-soluble graphite, oil-soluble silicone oil, water-soluble silicone oil, mineral oil and graphite in paste oil Since the coating is continuously sprayed on the mold, the accuracy deteriorates due to the accumulation of residual carbon in the mold, which causes the mold to be degreased and cleaned.The aluminum surface is oxidized early, and the upper surface is degreased, cleaned, and oxidized due to the residual non-adhesion. It takes time and effort to carry out film surface treatment, and the working environment becomes poor as the black powder flies onto the graphite powder and residual carbon powder.

Yield is poor because it does not prevent oxidation. The present invention provides better lubrication, mold release, and non-oxidizing agent composition example 3.4.7 Automatic spray coating on the mold under the same conditions as before, automatic pouring, and observation of the condition of the aluminum and mold surface after cooling. Even in this case, the metal surface is smooth with no roughness, has an aluminum metallic luster, is non-oxidized, and has no residue, so cleaning can be omitted and continuous use is possible.Since it is non-oxidized, the yield is improved. As for the working environment, there is no black powder, which improves the working environment.

Practical example 3 Conventionally, oil-soluble graphite and silicone oil were used as mold, lubricant, and mold release agents in the mold casting method, but in the case of graphite, black (
The working environment is such that residual carbon does not adhere to the inner surface of the mold, and the mold surface must be cleaned regularly because it adheres to the surface of the cast.The surface of the mold is oxidized, and some residues are coated afterwards, so cleaning is necessary. The same goes for silicone oil. The present invention is based on the results of automatic spray coating of composition example 3.4.7.8 on a mold, automatic pouring, and observation of oxidation and residue on the inner surface of the casting mold after cooling. Example 3.4
．． 7.8 In all cases, the surface skin was smooth without oxidation and had a metallic luster. As for the residue, 4.7 was not visible to the naked eye.

Regarding composition example 8, a small amount of residue was observed, but it was enough to be used automatically. Good lubrication and mold release, and no oxidation improves yield. Since there is no residue, the process of cleaning the casting mold can be omitted, and the whole process is completely maintenance-free, resulting in a reduction in costs.

Practical example 4 Swedish horizontal Nya net shape method (pultrusion method) Traditionally, copper, copper alloy, and brass were automatically poured into a round graphite mold.No lubricant or mold release agent was used at the inner interface of the mold, so when the mold was pulled out. The mold interface was severely worn and the copper surface was oxidized, so the surface was cut.In the present invention, Composition Example 1.2.6 was sprayed from the top and bottom two places for lubrication, mold release, and oxidation prevention, and the mold was pulled out. As a result of observing the condition of the copper surface of the product that came out, it was found that it was smooth and had a metallic luster similar to that of copper metal.

Since it does not oxidize, the yield has improved slightly.

Graphite molds are expensive and have a long rotating wheel life due to reduced wear.

hand Continued Supplementary Positive book

Claims (1)

[Claims] 1. Vegetable oils such as rapeseed oil and soybean oil and liquid paraffin oil;
Contains at least one type of oil selected from the group consisting of mineral oils such as mineral oil and 1 to 20% by weight of tetrafluoroethylene resin based on the total weight, and the tetrafluoroethylene resin is colloidally dispersed in the oil. A lubricant with anti-oxidation properties for high temperature metal surfaces. 2. Vegetable oils such as rapeseed oil and soybean oil and liquid paraffin oil,
At least one type of oil selected from the group consisting of mineral oils such as mineral oil, a tetrafluoroethylene resin and boron nitride, the total weight of the tetrafluoroethylene resin and boron nitride is 1 to 20% based on the total weight. % by weight and has an antioxidant function for high temperature metal surfaces in which tetrafluoroethylene resin and boron nitride are colloidally dispersed in oil.