JPS6376792A - Material for preventing sticking of welding spatter - Google Patents

Abstract

PURPOSE: To extend the use period of a preventive agent and to decrease the number of recoating so as to improve efficiency in arc welding of metallic parts by specifying the compsn. of an oil agent to be coated to a welding nozzle. CONSTITUTION:30-78.9% base oil by weight, 0.1-10% wax, 1-30% boron nitride powder, and 20-30% surface-active agent are incorporated as the preventive agent to be coated to the welding nozzle. The preventive agent is diluted with water to prepare 10-60wt.% emulsion which is then coated to the nozzle. The base oil is easily flowable therein and has the effect of coating the nozzle uniformly. The wax contributes to an improvement in the heat resistance and mechanical strength of the film and has the effect of dispersing the boron nitride into the base oil. The boron nitride protects the spatters from the base oil and wax by its heat resistance. The surface-active agent has the effect of dispersing and emulsifying the mixture composed of the base oil, wax and boron nitride into water and therefore, said agent accelerates the uniform sticking of the oil agent to the nozzle surface.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a welding spatter adhesion inhibitor that is applied to a welding nozzle during arc welding of metal parts to prevent welding spatter from adhering, thereby achieving stable welding. It is something.

(Prior art) Conventionally, paste, grease, or liquid oil is applied to welding nozzles or welded metal parts to form a film to prevent welding spatter from adhering to the nozzles or metal parts. Ta.

The components of these oils include mineral oil, fatty oil, synthetic oil, etc. as the base oil, fatty acids, organic film forming agents such as metal soap, graphite, molybdenum disulfide, zirconium oxide, etc.
Those containing inorganic anti-adhesion agents such as aluminum oxide were used.

(Problems to be Solved by the Invention) Among the conventionally used oils, those in the form of paste, grease, or high viscosity liquid tend to adhere in excess, making it difficult to remove and reapply. It becomes difficult to do.

Anti-welding agents are added to supplement the oxidation and heat resistance of the base oil and film-forming agent, but graphite and molybdenum disulfide are easily oxidized at high temperatures and decompose at 400°C, making them less effective. lose. Zirconium oxide and aluminum oxide are 800
It is stable at ~1500℃, which is good, but the former has a specific gravity of 5.
．． 6 to 5.89, and the latter is as large as 3.99, so even if it is added to an oil and dispersed, it is easy to separate, and it is difficult to make it exist uniformly in the coating film, resulting in poor adhesion prevention effect.

Therefore, these conventional oils have the problem that they are not suitable for the purpose of high-efficiency welding, which is recently required to increase the number of welds to be welded between once application and reapplication.

(Means for Solving the Problems) In order to achieve such high efficiency welding, the present invention fundamentally reconsiders the composition of conventional oil agents and pursues a logical composition, and thus achieves the advantageous results. The compositional features of the present invention are as follows, which are the main points of the means for solving the problems.

1. The oil agent is an emulsion-type water-soluble oil agent, and a thin viscosity emulsion is applied to the nozzle to evaporate water and leave a uniform thin oil film to avoid excessive adhesion.

2. Oxidation resistance was improved by using oxidation-resistant synthetic oil, especially ester-based synthetic oil, together with mineral oil as the base oil.

3. Wax, especially a high melting point, hard wax, was used as a film forming agent to provide an excellent spatter adhesion prevention effect even with a thin film, and to improve oxidation resistance.

4. The above-mentioned graphite, molybdenum disulfide as a welding inhibitor,
Various materials were investigated, including zirconium oxide, but the best results were obtained with boron nitride. This is because boron nitride is stable up to 1,000 to 1,050°C and has excellent heat resistance, and also has a low wetting property with metals, and has a specific gravity of 2.23, which is higher than molybdenum disulfide, zirconium oxide, and aluminum oxide. It is known as a solid lubricant because it is extremely small, stable at high temperatures, difficult to weld to metals, and easily dispersed evenly in oils and coatings. This is thought to be due to the fact that it has lubricity, which is advantageous for removing attached spatter.

As a result of our research, the present inventors discovered for the first time that boron nitride has unique properties not found in other anti-welding agents and is extremely suitable as an anti-welding agent. This is the basis of the invention.

Therefore, the present invention provides a welding spatter adhesion inhibitor that is applied to a welding nozzle to prevent welding spatter from adhering to the base oil.
78.9% by weight, wax 0.1-10% by weight, boron nitride powder 1-30% by weight, surfactant 20-30% by weight
This is a welding spatter adhesion inhibitor characterized by containing the following: At the time of use, it is diluted with water and applied to a nozzle as an emulsion of 10 to 60% by weight.

(Function) The base oil is a synthetic oil and mineral oil, which is the main component of the film after the water in the oil emulsion applied to the nozzle evaporates, and has the effect of uniformly covering the film. Synthetic oils include ester-based synthetic oils such as n-butyl stearate and 2-ethylhexyl palmitate, diester-based synthetic oils such as di-2-ethylhexyl sebacate, and diisooctyl adipate, and polypropylene glycol monomethyl ether. Synthetic polyalkylene glycol oils such as polyalkylene glycol synthetic oils and silicone synthetic oils such as polymethylphenylsiloxane can be used, but ester synthetic oils have excellent oxidation resistance, so they are used alone or as a mixture with mineral oil. It is necessary to.

The mixing ratio of synthetic oil and mineral oil is preferably 10:90 (weight ratio) with more synthetic oil.

The wax increases the heat resistance and mechanical strength of the coating,
It also acts to disperse boron nitride into the base oil, including petroleum waxes such as paraffin wax and microcrystalline wax, natural waxes such as carnauba wax, beeswax, and montan wax, stearic acid amide, N
, N'-ethylene bisstearamide, polyethylene wax, polyurethane wax, tocosyl behenate, tetracosyl lignocerate, and other synthetic waxes can be used, but high-melting waxes with a melting point of 70°C or higher, especially high melting point of 100°C or higher can be used. is preferred.

Boron nitride powder has the ability to protect spatter from base oil and wax due to its heat resistance, and it must be in powder form and easily dispersed in base oil and wax.
Preferably, the average particle size is in the range of 0.1 to 10 μm.

The surfactant has the function of dispersing and emulsifying the base oil, wax, and boron nitride mixture in water, and also has the function of promoting uniform adhesion of the oil agent to the nozzle surface.

Nonionic activators such as polyoxyethylene nonylphenyl ether and polyoxyethylene sorbitan oleate,
Anionic activators such as sodium petroleum sulfonate, sodium sulfosuccinate, triethanolamine oleate, potassium oleate, etc. are used.

The significance of limiting the content of each component above is that if the other components are below their respective lower limits relative to the base oil, they will not be effective, and if the wax exceeds the upper limit, the fluidity of the coating will be poor and it will be difficult to form a uniform coating, and boron nitride will If the upper limit is exceeded, the coating becomes brittle. If the amount of surfactant exceeds the upper limit, the adhesion of the oil film to the emulsion nozzle surface will be poor (this is why it becomes difficult to form a uniform film). You can also add.

(Example) Each Example and Comparative Example having the composition shown in Table 1 was prepared by blending each component and mixing them uniformly, and each 50% by weight emulsion was regenerated and used as a sample.

Each sample was tested using the following test method, and the effects were compared and confirmed.

Test method A, small AC arc welding test (laboratory test) Ceramic welding nozzles are used in welding the arm joints of rear axle housings at automobile factories, so the test was conducted under the same conditions.

50 x 50 of ceramic material (aluminum oxide)
Each of the above samples was coated on one side of an X5 (Tsuru) plate and dried for 1 hour in a constant temperature bath at 105°C to obtain a test piece.

Next, the four test pieces were arranged in a 300 x 300 x 50 (1
It was placed in a square shape with sides of 50 mm on a cast iron plate (Kasumi) and stood upright with the coated surface facing inward.

Next, each test piece was placed on a cast iron plate using a small AC arc welding machine (Toyo Arc TK-150, secondary current 90/130 A, no-load voltage 50 V, usage rate 20%). Arc welding was performed at the center point for 1 minute.

After that, each test piece was cooled and washed with a 1:1 mixed solvent of ethyl alcohol and ethyl ether using an ultrasonic cleaner.After drying, the weight of each piece was measured, and the weight difference before and after the test was calculated. The amount of spatter attached (shown in Table 1) was determined, and the quality was determined based on the amount.

B. Automotive factory field test A total of two types of welding spatter adhesion prevention agents, the present invention (Example 2) and commercial product A, and conventionally used 90 turbine oil in the welding line of 75 Dragon rear axle pans at an automobile factory. Three types of wipes were applied to a ceramic welding nozzle, and the amount of spatter deposited on the nozzle and the period from application until the anti-adhesion effect disappeared and re-application was determined were 2 to 2 for each wipe. Obtained. Therefore, the usage period until re-testing is 6 for 90 turbine oil.
It has been found that a significantly longer effect can be obtained, which is 3 to 4 times that of commercially available product A.

This means that the operating rate of the welding line will be significantly improved by using the product of this invention, and in particular, recent welding lines have adopted arc robots and are fully automated, and in the case of re-application, the entire line is stopped. Considering the necessary circumstances, the fact that we were able to significantly extend the usable period and drastically reduce the number of re-applications in this way helps us achieve our goal of increasing welding efficiency.
This was an extremely significant result.

(Effects of the Invention) When the anti-adhesion agent of the present invention, which is characterized by containing base oil, wax, boron nitride powder, and surfactant in a specific ratio, is applied to a welding nozzle, experimental results were observed as shown in the test results column above. It was confirmed that the effect of preventing spatter adhesion was extremely excellent both in the room and in the field, and that the object of the invention could be achieved.

Claims (1)

[Claims] 1. Welding spatter adhesion prevention agent applied to welding nozzles to prevent welding spatter adhesion, base oil 30 to 78.9
A welding spatter adhesion inhibitor characterized by containing 0.1 to 10% by weight of wax, 1 to 30% by weight of boron nitride powder, and 20 to 30% by weight of a surfactant.