RU2357831C2 - Foundry-forging machine coolant - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention refers to foundry engineering. Said coolant contains, wt %: gear oil 25-35, polymethylsiloxane 0.2-0.5, semi-synthetic unsulphonated liquid "Caraidel 2" 25-44 and water - the rest.

EFFECT: improved separative power of coolant ensured.

2 tbl, 1 ex

Description

The invention relates to foundry, and in particular to cutting fluids used in the hot processing (forging) of brass castings.

It is known to use various cutting fluids (coolant) when casting mainly non-ferrous metals and alloys into metal molds. Most of these coolants, consisting of a significant number of components, are designed to produce blanks by injection molding of aluminum alloys having a low casting temperature (about 750 ° C). For example, multicomponent coolant compositions according to copyright certificates (a / c) No. 1183277 (1985), 466064 (1975), 522893 (1976), 557861 (1977) include solvents, stabilizers, fillers and water. A significant drawback of all of these coolants is the use of solid fine powders as fillers, such as graphite, soot, cryolite, clay, distensillimanite, blast furnace dust, petroleum coke and a number of other products insoluble in water and organic solvents that disable automatic snap-in lubrication systems . The listed coolants also have insufficient heat resistance; therefore, their use for hot pressure treatment of more refractory alloys than aluminum is difficult.

The manufacturing process for preparing billets on a casting and forging machine (LMC) combines the operations of free casting an alloy into a metal mold, its primary crystallization, followed by pressure treatment in forging dies, crystallized from the surface and having a viscous core of brass castings. Castings in forging dies experience significantly higher loads than melts during injection molding, therefore, strong adhesion arises between the working surface of the dies and the workpiece, often leading to the latter being welded to the dies. Due to the narrow crystallization interval of LC40C brass, from which the castings are obtained, the temperature range of the hot pressure molding of the castings must also be narrow, within 910–915 ° С. At a lower or higher temperature outside the specified range, processing is not possible due to the low ductility of the alloy or weld. It increases the ductility of the alloy and prevents the weld of workpieces to the surface of the dies using special coolants based on mineral oils. However, most coolant compositions intended for hot and cold metal forming (a / c No. 1097648, 1097649, 1097653, 1984), tested in production upon receipt of blanks from brass on paintwork materials, have insufficient heat resistance, due to which the weld of the castings to the surface of the dies is not warned, and sometimes amplified. Due to the presence of solid finely divided fillers in the aforementioned coolant, their use for automatic lubrication systems on coatings is difficult.

Some enterprises that have implemented the process for producing blanks on paintwork materials (KAMAZ, GAZ) use liquids of the “Graphitol E” type [6] as a lubricant, which are water-oil emulsions with surface-active additives and solid filler (fine graphite). “Graphitol E” liquid has satisfactory separating properties, facilitates the removal of blanks from forging dies, prevents welding, however, the presence of solid, although fine particles of graphite in it, not only quickly clogs the pipelines and destroys the automatic LKM lubrication system, but also worsens sanitary -hygienic working conditions and production culture, although it is generally believed that graphite plays the role of a solid lubricant [1].

Of all the known coolant compositions recommended for coating the working surfaces of metal molds and dies, the closest to the proposed in essence and the achieved results is the liquid "Elitol E" [5], produced by the domestic industry in accordance with a / c No. 1542034 (1988 g.). The composition of the liquid includes the following components: water, mineral (cylinder) oil, antifoam agents (polymethylsiloxane and silicon dioxide), organic fatty acid (polyoxyethylated stearic), organic solvent (kerosene), colloidal sulfur and urea. The technology for preparing the liquid is quite complicated: the components are repeatedly heated - mineral oil first to 70-80, then to 125-130 ° C, stearic acid is first dissolved in hot water, mixed with urea, which decomposes into ammonia and carbon dioxide at 130 ° C , and with intensive and thorough mixing and emulsification in high-speed mixers or colloidal mills at elevated temperatures, the gases escape into the atmosphere during the preparation of the liquid. The recommended field of application of the known coolant selected as a prototype is the lubrication of the working surfaces of molds and plunger pairs of die casting machines of aluminum alloys. Substances additionally introduced into the coolant — colloidal sulfur and silicon dioxide — are toxic and insoluble in water or in organic solvents with finely divided solid products, the use of which in the composition of the coolant is undesirable. During production tests, an insufficient separating ability of the known liquid was revealed, although it is technologically advanced if it is used in automatic lubrication systems due to the absence of solid fillers.

The aim of the present invention is to provide such a coolant intended for coating the working surface of forging dies of paintwork materials, which, along with higher separating properties during hot pressure treatment of brass castings, would have a simple composition, simple preparation technology (without heating components and special emulsification), it did not contain solid fillers such as graphite, cryolite and other components, including toxic ones. This goal is achieved by the fact that in the known composition of the coolant based on mineral oil, antifoam - polymethylsiloxane and water, an additional sulfide-free semi-synthetic liquid "Karaidel 2" is additionally introduced in the following ratio of components (in wt.%):

Mineral oil (transmission) - 30-35 Polymethylsiloxane - 0.2-0.5 Karaidel 2 - 24-45 Water - the rest.

The use of additional additives of colloidal sulfur, urea, kerosene and fatty acids is not necessary, since all of these components in the required quantities are seated in transmission oil and Karaidel 2 fluid.

Transmission oils are a mixture of high quality distillate and residual oils with additives of phosphorous, chloride and sulfur compounds having anti-seize, anti-wear, antioxidant and anti-foam properties.

In accordance with the technical conditions [3], the semi-synthetic liquid “Karaidel 2” is a balanced composition of industrial, synthetic and vegetable oils with additives of synthetic fatty acids, glycol and amine esters of fatty acids, contains emulsifiers, corrosion inhibitors, when mixed with water, it forms finely dispersed emulsions , and therefore special emulsification is not required. In addition, the composition of the liquid "Karaidel 2" includes sinterol, neonol, triethanolamine, diethanolamine, sunflower oil, rapeseed oil and other substances that improve the technological properties of the coolant.

The proposed coolant is prepared as follows. SAE 85W-90, APIGL-5 gear oil is poured into a metal or plastic container [2], the KE10-01 organosilicon compound is introduced, which is a 70% aqueous emulsion of PMS-400 organosilicon liquid (polymethylsiloxane) according to TU 6-02-587 -75, mixed for 2 minutes with a wooden hand mixer (a mechanical mixer can also be used), semi-synthetic Karaidel 2 semi-synthetic sulfonate-free liquid is added to the mixture, mixed for 5-7 minutes, hot water is added (water temperature is about 50-60 ° C) mixing again t for 3-5 minutes, after which the liquid can be used as a release coating (paint supplies placed in the container). As can be seen from the above characteristics, the composition of the liquid and the technology for its preparation are much simpler and more affordable, coolant can be prepared at any enterprise, and special equipment is not required: high-speed mixers, mills, heaters.

Examples of specific performance.

To assess the separation ability of the proposed coolant, comparative production tests were carried out upon receipt of brass blanks LC 40C GOST 17770-80 on a casting and forging machine model 4167 of the design NIITAVTOPROM. Cutting fluids were preliminarily prepared and tested alternately on the same coatings. Before application to the forging dies, concentrated liquids were additionally diluted with water in a ratio of 1:10 and the resulting compositions were sprayed onto the working surfaces of the dies with a spray gun. After pouring brass into a copper casting chill and holding it in a chill mold for 5 seconds, the casting together with the gating system (section) was automatically placed in the forging die using transport grippers, after forging, the section was automatically moved to the cutting stamp by transport grippers where the gating system was separated from the casting . The separation ability of liquids was evaluated by the number of sections removed from the forging dies with a single application of coolant on the surface of the stamp. In the case of insufficient separation ability of the coolant, the section was welded to the surface and was not removed from the stamp, the cycle was broken, the machine automatically stopped.

The compositions of the test coolants are shown in table 1, and their separating ability in table 2.

Table 1
The composition of the test coolant Components The content in the compositions, wt.% one 2 3 four 5 6 7 8 Gear oil 24 25 thirty 34 35 36 - - Cylinder oil " - - - - - 35 - Stearox - - - - - - fifteen - Kerosene - - - - - - 12 - Urea - - - - - - 13 - KE 10-01 (PMS-400) 0.1 0.2 0.3 0.4 0.5 0.6 0.5 - Colloidal sulfur - - - - - - 0.4 - Silica - - - - - - 0.01 Karaidel 2 24 25 thirty 34 44 45 - - "Graphitol E" - - - - - - one hundred Water 51.9 49.8 39.7 35.6 20.5 18,4 24.09 - Total one hundred one hundred one hundred one hundred one hundred one hundred one hundred one hundred Note: before applying to the working surfaces of the dies, the concentrates were diluted with water in a ratio of 1:10, respectively.

table 2
Liquid Separation Composition No. from table 1 one 2 3 four 5 6 7 8 Dividing the ability (quantity fifteen 19 28 38 39 24 eighteen fifteen removals at one-time coating)

The analysis of table 2 shows that the compositions of the coolant with the liquid "Karaidel 2" (No. 2, 3, 4, 5, 6) have a higher separation capacity compared to the closest analogues previously used in the production (compositions No. 7 and 8). Compounds No. 3, 4, 5, 6 have the highest separation ability. The use of composition No. 2 is also possible, since it is not inferior to the prototype in terms of separation ability, but is more economical and simple in composition. In addition, practice has shown that composition No. 6, despite the relatively high separation ability, is not technologically advanced, because due to the large number of oils in the coolant, as well as the high temperature, soot forms on the working surfaces of forging dies due to thermal destruction of the Karaidel 2 fluid. Therefore, during the operation of foundry forging machines, periodic removal of soot is necessary, leading to a decrease in productivity and worsening working conditions. The consumption of components also increases, which increases the cost of the process. Therefore, increasing the flow rate of the Karaidel 2 liquid to more than 44 wt.% Is technically and economically impractical. A decrease in the concentration of Karaidel 2 liquid of less than 25% is also impractical due to the insufficient dividing ability of the coolant. Thus, the proposed coolant, additionally containing the liquid "Karaidel 2" in an amount of 25-44 wt.%, Provides high technical and economic indicators: increases labor productivity and quality of castings due to the stabilization of the paintwork.

The proposed technical solution has the following common features with the prototype:

- mineral oil as a base;

- multicomponent composition, including wetting agents, emulsifiers, extreme pressure, antiwear, antifriction and other additives;

- the absence of solid fillers in the coolant;

- satisfactory dividing ability.

The salient features of the proposed composition and prototype:

- a simpler composition and cooking technology;

- the absence of toxic components, such as colloidal sulfur and silicon dioxide;

- the use of high quality gear oil;

- additional inclusion of “Karaidel 2” fluid in the coolant composition — a balanced composition of synthetic and vegetable oils with additives of synthetic fatty acids, their esters and amines, synterol, neonol, organic solvents and other components.

Mineral-based lubricating coolant with the addition of semi-synthetic non-sulfonate Karaidel 2 fluid was tested under the production conditions of Ural Automobile Plant OJSC and a decision was made to introduce it.

The following composition of the coolant (wt.%):

Mineral oil - 25-35 Polymethylsiloxane - 0.2-0.5 Liquid "Caraidel 2" - 25-44 Water - the rest.

LITERATURE

1. Shebatinov M.P. and others. High-strength cast iron in mechanical engineering. - M.: Mechanical Engineering, 1988, - p. 87.

2. Oils for engines and transmissions - Za Rulem magazine 2/93, p.14-15.

3. TU 0258-003-12783932-93.

4. TU 6-02-135487 - Lubricating and cooling fluid of the "Elitol E" type.

5. TU 6-02-1121-77 - Lubricating and cooling fluid of the “Graphitol E” type.

Claims (1)

Cutting lubricant for dies of foundry-forging machines in the production of brass cast billets, subjected to hot processing, containing water, mineral oil, polymethylsiloxane, characterized in that it additionally contains semi-synthetic non-sulfonate liquid "Karaidel 2", and as a mineral oil - gear oil in the following ratio of ingredients, wt.%:
Transmission oil 25-35 Polymethylsiloxane 0.2-0.5 Liquid "Caraidel 2" 25-44 Water Rest