SU1754246A1 - Bearing assembly of roll of hot rolling mill - Google Patents

Description

The presence in the base composition of a surfactant and metal powder made of copper or copper alloy makes it possible to remove corrosion products from the surface of the roll neck and also to apply a protective copper coating to the neck surface by mechanical and chemical transfer. In addition, the surfactant forms an adsorbed protective layer on the surface of the cervix that prevents the hydration and corrosion of the metal. At the same time, the water on the surface of the cervix, along with the mineral salts dissolved in it, plays the role of a surfactant contribute to protecting the metal from corrosion.

The drawing shows the device, a longitudinal section.

The device comprises a bearing housing 1 for a roller neck 2, a non-metallic liner 3, an additional liner 4 with abrasive Grinding powder 5, previously deposited on the substrate b, with a lubricating lubricant component and a surfactant (surfactant).

The roll neck is cooled by means of a cooling water supply pipe 7 and a collector 8. To improve the working conditions, a lubricant layer 9 is applied to the contact surface of the additional liner 4, and the additional liner is fixed on the surface of the non-metallic liner to the bonding base.

An abrasive powder with a particle size of 3–1250 µm, a microhardness of 2060–10,000 N, and a density of (2.48–4.28) х103 к / mm2 serves as an abrasive grinding powder. The base contains a metal powder made of copper or a copper alloy with a particle size of not more than 200 microns. The powder may be copper powder of the type PMS-B, brass powders of the type L80, L70, bronze powders of the type Brü, Br. OC10-2, or other powders based on copper.

Table 1 shows the compositions of powders based on copper and copper alloys.

The particle size of these powders is 50-200 µm, the bulk density is 2.6-4 g / cm3.

Epoxy resorcinol resin AREM-2, epoxy resin Dianova ED-5, ED-6, ED-20 or another polymer can serve as bases. Ionogenic or nonionic surfactants, metallic soaps and others can be used as surfactants. Lubricant can be solid lubricant

based on graphite, molybdenum disulfide, etc.

Aspect Ratio: Metallic Powder1-25

Surfactant 0.2-10 Lubricant component 3-20 Binder Rest For experiments to select the proposed quantitative ratios, the results were compared with similar prototype data. The results are presented in table 2. In experiment 1, the concentrations of the components of the base of the additional liner were at medium levels. Compared to the prototype (experiment 18), the support life increased by 22% and the productivity increased from 68 to 70 t / h

In experiment 1, the concentrations of the components of the base of the additional insert were at medium levels. Compared with the prototype (experiment 18), an increase in the support resistance by 22% and an increase in productivity from 68 to 70 t / h was obtained.

In experiments 2–4, the concentrations of metal powder, surfactant, lubricant component, and binder were found on the lower acceptable limits. Achieved a positive effect. Maintaining the concentrations of these components at the level of the upper limits (experiments 5-7) also ensured the achievement of a positive effect.

Simultaneous maintenance of the concentrations of the base components at the lower (or upper level (experiments 8 and 9) allowed us to obtain a positive effect.

A decrease in the concentration of the metal powder below the lower permissible limit (test 10) did not achieve a positive effect, since this amount of powder is not enough to effectively polish the shaft journal and protect it against corrosion.

The surfactant content in the base is less than 0.2% (test 11) does not ensure the formation of a protective layer of copper on the surface of the cervix and thus does not allow to increase the support life and increase the mill productivity,

A decrease in the concentration of the lubricant component to 2.8% (experiment 12) results in an increase in frictional forces on the contact surfaces and rapid wear of the additional liner, as a result of which the support efficiency decreases significantly. The strength of friction also increases with increasing metallic concentrations.

powder to 25% (experiment 13), which leads to wear of the liner and reduce the effectiveness of the support.

An increase in the surfactant concentration (test 14) and the lubricant component (test 15) above the upper allowable limits leads to a decrease in the strength of the additional liner and its destruction under the action of rolling loads. The expected effect is not achieved.

Maintaining the concentrations of the base components at levels below the lower limits (experiment 16) and above the upper limits (experiment 17) also does not lead to a positive effect.

The device works as follows.

The supports are installed in a rolling stand cushion (not shown) whereupon the rolls are driven into rotation. During the rolling process, under the action of metal pressure on the roll, the neck 2 is applied to liner A, compressing a layer of grease 9 and abrasive grinding powder 5 to lubricate and polish the neck 2 The wear products are removed from the surface of the neck by cooling water supplied from the collector 8 After producing layers 9 and 5, layer 6 begins to work, ensuring lubrication of the surface of the neck In addition, due to the presence of metal powder in the base made of copper or copper alloy and surfactant, is carried out by depositing a layer of copper on the surface of the neck of the roll, protecting it from hydrogenation and corrosion.

Thus, as a result of industrial tests, it has been established that while maintaining the concentrations of the components of the base of the additional liner within the specified limits, the application of the proposed roll support for a hot rolling mill provides an increase in the support life and an increase in the mill

EXAMPLE 1 (Test 1) Roller bearings were used in cages x 9 and 10 of the rolling mill 300, each of which contained a cast iron bearing housing, a textolite insert, an additional insert consisting of a base coated with 150 abrasive powder. micron, microhardness 3000 N density of 2.48 g / cm. The base contained copper powder type PMS-8 with a particle size of 50-150 μm, lithium stearate (surfactant), graphite (lubricant component) and hardened epoxy resin of the type ED-6 (binder) with the following component content kg (wt%)

Copper powder0 12 (12)

Lithium stearate 0 04 (4)

Graphite0.1 (10)

Epoxy resin (0.74) (74)

In the mill, round steel (St 3) with a diameter of 32 mm was rolled from a square section billet measuring 98x98x4400 mm. Industrial cooling water under pressure of 0.05 MPa in the amount of 60 grams per stand was applied to gauges and roll necks.

After rolling 1000 tons of metal, the rolls were transshipped. Ojes transshipments replaced the GG liners from 8 times (the prototype has only 6). In addition, the mill capacity compared with the prototype increased from 68 to 70 t / h.

EXAMPLE 2 (Experiment No. 8) In cages x 9 and 10 of the rolling mill 300, roll bearings were used, each of which contained a cast iron bearing housing, a textolite insert, and an additional liner consisting of a base with a size of abrasive powder applied on it. 300 mm, microhardness 5000 N, density 3.0 kg / cm- The base contained bronze powder of type BR 10 with a particle size of not more than 160 mgm sodium palmitate (surfactant), molybdenum disulfide (lubricant component) and hardened epoxy resin of type ED-20 ( binder) with the following content of components g (weight%).

Bronze powder 0.01 (1) sodium palmitate 0.002 (0.2)

Molybdenum Disulfide 0.03 (3) Epoxy resin0.958 (95.8)

Angular steel No. 5 was rolled on the mill from a billet measuring 98x98x4400 mm. The material of the workpiece is steel 5. Industrial cooling water under pressure of 0.06 MPa in the amount of 62 m ° / h per stand was applied to calibers and roll necks.

After rolling 1000 tons of metal, the rolls were transshipped. Transshipments without replacing liners were made 10 times, which is significantly higher than the number of transshipments compared with the prototype. Productivity also increased from 68 to 71.4 t / h. .

PrimerZ (experiment Ns 9) Roller bearings were used in the cages x 9 and 10 of the rolling mill 300, each of which contained a cast iron bearing housing, a textolite insert, an additional insert consisting of a base with a 1000 µm abrasive powder coated on it, with a microhardness of 7000 H, with a density of 3.8 g / cm3. The base contained a powder of L80 type brass with a particle size of not more than 200 μm PEG-300 polyethylene glycol (surfactant), graphite (lubricant component) and hardened AREM-20 epoxy resin (binder) at the following content components, kg (wt.%) 1

Brass Powder0.25 (25)

Polyethylene glycol 0,10 (10)

Graphite, 0.20 (20)

Epoxy resin0.45 (45)

Angular steel No. 5 was rolled on the mill from a billet measuring 98x98x4400 mm. The material of the workpiece is steel 5. Industrial gauge water under pressure of 0.06 MPa in the amount of 65 m3 / h per stand was applied to calibers and roll necks.

After rolling 1000 tons of metal, the rolls were transshipped. Transshipments without replacing liners were made 8 times, which is 23-33% higher than the number of transshipments compared to the prototype. Capacity increased from 68 to 71.1 t / h.

The use of the proposed roll support allows an increase in mill productivity by 3%.

Claims (1)

Claims of the Invention A roll support for a hot rolling mill comprising an open bearing housing with a non-metallic liner and a stationary additional liner made in the form of a substrate containing a lubricant component and an abrasive grinding powder applied to the substrate from the side of the roller neck, differing in that, in order to increase the support resource, the lubricant component of the base contains a binding and surface-active substance and metallic copper-containing powder in the following ratio, wt.%: Metal matic cupriferous powder 1-25 Surfactant veschestvo0,2-10 Lubricating component 3-20 Binder rest The chemical composition of copper and alloys based on it, the number of alloy ingredients, weight,% Table 1 table 2