JPS594212B2 - Titanium Mataha Titanium - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a new treatment method for applying an excellent lubricating film for cold working to the surface of materials such as rods and tubes made of titanium or titanium alloys.

Dried titanium alloy is an excellent metal material with excellent heat resistance, corrosion resistance, specific strength, etc. However, there are many problems with processing, and both hot and cold processing is difficult, especially during processing. It is well known that severe seizure5 is a major drawback and a major hindrance to cold drawing and rolling of rods, pipes, etc., and various special products are used to prevent this seizure. Although lubricants are used, the conventional lubricant coatings do not have sufficient effects as described below1.
The reality is 0.

In addition, swaging has been applied to titanium materials as a processing method to avoid the severe seizure mentioned above, but although this processing method can increase the processing rate per pass, the processing speed is limited by drawing and cold building machines (rolling machines). ) is significantly slower than 15, and is still a problem in terms of productivity.

Based on the above-mentioned circumstances, the present invention has developed a lubricating coating for cold working using titanium that can be processed at a processing speed similar to that of general stainless-tone carbon steel and that also provides stable quality. - was made for the purpose of forming it on the surface of titanium alloy material, and its characteristics are that the material made of titanium or titanium alloy is annealed in an oxidizing atmosphere to generate an oxide film on the surface, Then, it is immersed in a calcium stearate solution diluted with a chlorinated organic solvent by 25%, and then dried, so that the calcium stearate is regenerated and adhered to the surface on which the oxide film has been formed.

Before explaining the present invention in detail below, the conventional lubricant and lubricant film formation will be described first.

Table 1 below shows conventional lubricants, and they can be roughly classified according to the type of lubricant film formed on the surface of the material: resin-based film type, chemical film type (fluoride).
, molybdenum disulfide coated type 35 (moly coat type), and these coatings are all formed on the metal skin of the material, and for this reason, vacuum annealing is usually performed to anneale the material. be. That is, titanium is highly active, and when annealed in the air, a large amount of oxide scale is formed and there is a risk of embrittlement due to hydrogen absorption, and vacuum annealing is used to prevent these problems.

Of course, it is possible to form the above film on the skin after removing the oxidized scale by performing atmospheric annealing with sufficient moisture control to prevent hydrogen embrittlement, but there are also problems here. If the annealing is performed at a relatively low temperature, such as simply strain relief annealing, the amount of scale produced is small and can be removed by pickling alone, but when heated at a high temperature, such as softening annealing for work hardening, the amount of scale produced is also small. In most cases, it can be removed by soaking in a salt bath containing caustic soda as the main component.
In addition, pickling is required, and it is too complicated to carry out such a process every time the work hardening is removed, so in the end, vacuum annealing has no choice but to The problem remains in terms of equipment costs.

Conventional lubrication has been described above, but its effects cannot be said to be fully satisfactory, as noted in the remarks column of Table 1.

In contrast, in the present invention, annealing may be performed in an oxidizing atmosphere such as the air, and the oxide scale generated by the annealing is not removed, but rather is used as a component of the lubricating film, that is, as a base. This is the most characteristic feature of the present invention.

That is, a calcium stearate layer is deposited on the oxide scale, and the two form a lubricating film.
When forming a calcium stearate layer, since the same agent is insoluble in water and soluble in organic solvents, it is dissolved and diluted in an organic solvent that can dissolve and evaporate it, that is, in the present invention, it is particularly diluted in a chlorinated organic solvent. Then, the annealed material is immersed in the same solution and then dried to form a calcium stearate layer. Attached Figures 1 to 3 show an example of titanium tube material treatment in order to explain the treatment method of the present invention. First, as shown in Figure 1, the titanium tube material was pickled through the feed roll 2. The titanium tube material 1 is charged into an annealing furnace 3, and annealed in the same furnace 3. This annealing is performed in the atmosphere, and the moisture in the tube material 1 and the furnace 3 is sufficiently controlled, that is, the moisture is removed. If this is done, there is no risk of hydrogen embrittlement, and oxide scale will be generated on the inner and outer surfaces of the tube material 1 during the annealing.

Next, as shown in FIG. 2, the annealed tube material 1 with oxide scale still attached is immersed in a calcium stearate solution 4 containing a chlorinated organic solvent stored in a dipping tank 5. Reference numeral 5 denotes a hanging wire, and the tube material 1 after annealing is bound and suspended by the same wire 6 and placed at the bottom of the dipping tank 5. After being left still, the binding rope 6 is loosened as shown in the figure. As a result, the stearic acid solution 4 comes into even contact with the tube material 1 and penetrates into the oxide scale layer.

This immersion may not cause a chemical reaction between the titanium oxide film (scale) and calcium stearate, and the purpose is simply to penetrate the film, so immersion for about 10 minutes is sufficient. After dipping, attach the hanging wire 6 as shown in Figure 3.
, 6 lift the tube material 1 from the dipping layer 5, lower one end to drain the liquid from the inner surface of the tube, and then set it on a table at an oblique angle to air dry.

In addition to natural drying, forced drying such as by blowing air is also possible.Especially when the room temperature changes rapidly or under high temperature conditions such as during the rainy season, dew may form due to the vaporization of the chlorinated organic solvent. However, the presence of moisture impedes lubricity, and especially in drawing, the influence of moisture is large and there is a risk of seizure, so it is necessary to dry the material thoroughly.

Therefore, in such cases, drying with dry hot air is preferred. In this way, a lubricating coating consisting of a calcium stearate layer coated with oxide scale as a base is formed on the tube material 1 after drying.

As described above, the method of the present invention includes annealing a material made of titanium or a titanium alloy in an oxidizing atmosphere, generation of oxide scale due to the annealing, immersion in a chlorinated organic solvent solution in which calcium stearate is dissolved, and after immersion. It is a processing method that consists of drying the material, and the annealing itself also serves as a base formation, that is, oxide scale formation. While chemical conversion reactions often lack certainty, the formation of oxide scale is extremely reliable, and the unevenness of the oxidized skin has the effect of doubling the adhesion of calcium stearate.

Calcium stearate is an inexpensive powdered lubricant that can be easily removed and has been used in the past, but when used on a base coat, the base coat is already coated with a resin coat or fluoride coat. However, in the present invention, the base film, that is, the oxide scale, is not originally a lubricating film, but rather is considered to be a hindrance to lubrication, and calcium stearate is the only film in the present invention. It is a lubricating agent for
Conventionally, there was no use of this agent as the sole lubricating agent.

In addition, the conventional method for adhesion of the same agent to the base coating is the powder form X adhesion, and it can be easily applied to the outer surface of the material, for example by holding it in your hand, but on the other hand, it is difficult to adhere to the inner surface of the tube. The cumbersome method used was to supply powder of the same agent from one end of each tube and then push a plug into the tube.

On the other hand, in the present invention, the same agent is made into a solution and sludge is soaked in the same solution, so there is no need to treat each pipe individually, and the inner and outer surfaces of a large number of pipe materials can be treated at the same time. This is also a major feature of the present invention. As described above, the coating means using calcium stearate as a solution is such that the dry coating layer adheres firmly to the surface condition of the base oxide scale, and when using a chlorinated organic solvent such as trichlorethylene or trichloroethane as an organic solvent, Since it is used in the drying process, it has a strong adhesion force, and even when handled after drying, the necessary amount remains attached.

By the way, when using a chlorinated organic solvent, it is natural that consideration must be given to its toxicity, flammability, etc., not limited to the present invention, and trichlorethylene is highly toxic and must be handled with care. In this respect, trichloroethane has low toxicity, and therefore trichloroethane is preferable.

In any case, to prevent pollution, it is important to increase the depth of the immersion tank, prevent vaporized vapor from escaping outside the tank, and take measures such as cold traps. In addition to the above-mentioned chlorine-based organic solvents, alcohols can also be used; however, although they are effective against pollution, alcohols are not only expensive but also have the disadvantage that they tend to retain moisture. There are practical problems.

Further, an example of a preferred composition of the stearic acid solution of the present invention is as follows.

(1) Calcium stearate Ca (Cl3H35O
2) 2・・・・・・・・・10Kf trichloroethane
・・・・・・・・・90t However, the concentration of calcium stearate has a wide tolerance in the direction of increasing concentration, so it does not interfere with the work, and even if there is solvent vaporization, the concentration will be maintained at about 8 to 20%. This is desirable.

As described above, the present invention does not require vacuum annealing as in conventional methods, uses only calcium stearate as the sole lubricating agent, and can form multiple films at the same time. It is stable and has an excellent lubrication effect, which simplifies the process and work.
The industrial value of the present invention is significant as it brings about a reduction in the manufacturing cost of products and an improvement in the quality of the products.

Finally, Table 2 below compares the advantages and disadvantages of the present invention and the conventional coating treatment method. This clearly shows that the method of the present invention is superior. In addition, 1~ in the table
The number 4 indicates the degree of excellence in each item, with 1 being the best and 4 being the worst.

[Brief explanation of drawings]

Figures 1 to 3 are explanatory views of the lubricant coating treatment method for cold working of the present invention, taking titanium tube material treatment as an example, in which Figure 1 is annealing, Figure 2 is immersion treatment in stearic acid solution, FIG. 3 shows draining after immersion. 1...Titanium tube, 2...Feed roll,
3... Annealing furnace, 4... Calcium stearate solution (organic solvent), 5... Immersion tank, 6
...hanging wire.

Claims (1)

[Claims] 1. A material made of titanium or a titanium alloy is annealed in an oxidizing atmosphere to form an oxide film on the surface, and then immersed in a calcium stearate solution diluted with a chlorinated organic solvent and dried to form the oxide film. A method for treating a lubricating film for cold working of titanium or a titanium alloy, characterized by regenerating and adhering calcium stearate to a surface on which a titanium or titanium alloy has been formed.