Ball joint bushing

Abstract

The utility model is a cylindrical part made of low-carbon corrosion-resistant austenitic steel with a face-centered cubic crystal lattice and a content of the following alloying components, in wt.%: nickel - 10-15; manganese - <2; molybdenum - 2-2.5; carbon - <0.07; silicon - <1.0; phosphorus - <0.045; sulfur - <0.02; chromium - 16.5-18.5; nitrogen <0.11; iron - everything else. The technical result of the claimed utility model is to increase the service life of the hinge joint bushing. 2 c.p. phyl., 2 fig.

Description

[0001] FIELD OF TECHNOLOGY

[0002] The utility model relates to the field of mechanical engineering, in particular to the designs of sleeves of articulated joints, and can be used, for example, as part of articulated joints that are used as part of loading arms, loading, handling, reloading sleeves, articulated pipelines and manipulators, loading levers for use at oil, chemical, gas terminals of sea and river ports, in installations for loading and unloading railway tanks and tank trucks, hose loading installations, bunkering installations for refueling sea and river vessels, as well as in installations for unloading food flowing products and connectors.

[0003] STATE OF THE ART

[0004] A hinged joint is known from the prior art, including an outer and an inner housing, one as a rotor, the other as a stator (see RU 2777679).

[0005] The technical problem inherent in the analogue is the low service life of the articulated joint.

[0006] This technical problem is caused by the fact that the housing does not contain a bushing, as a result of which there is no heat-insulating chamber formed by the housing and the bushing, which helps to reduce the cooling rate of the hinge in the case of transporting a low-temperature medium.

[0007] The primary interaction with the transported medium is carried out by the inner casing, which reduces the service life of the swivel joint, especially when used in cryogenic environments.

[0008] The closest analogue is the sleeve of the hinge joint, which is a cylindrical part with projections intended for installing the sleeve in the hinge joint (see RU 2776400 C1).

[0009] The technical problem inherent in the analogue is the low service life of the ball joint bushing.

[0010] This technical problem is caused by the fact that the bushing is not made of steel that is most suitable for operation at low temperatures, which reduces the service life of the articulated joint bushing.

[0011] REVEALING THE ESSENCE

[0012] The technical result of the claimed utility model is to increase the service life of the articulated joint bushing.

[0013] Also, the cold brittleness of the swivel joint bushing is further reduced, which enables the bushing to operate in cryogenic environments and increases the service life of the swivel joint bushing when working with cryogenic environments.

[0014] The stated technical result is achieved by the following design of the articulated joint sleeve.

[0015] The swivel bushing is a cylindrical part used in the swivel joint.

[0016] The bushing is made of low-carbon corrosion-resistant austenitic steel with a face-centered cubic crystal lattice and the content of the following alloying components that increase the steel's resistance to low temperatures, wt.%:

[0017] nickel - 10-15;

[0018] manganese - <2;

[0019] molybdenum - 2-2.5;

[0020] carbon - <0.07;

[0021] silicon - <1.0;

[0022] phosphorus - <0.045;

[0023] sulfur - <0.02;

[0024] chrome - 16.5-18.5;

[0025] nitrogen - <0.11;

[0026] hardware - everything else.

[0027] The stated steel composition is optimal for a bushing operating in cryogenic environments for the following reasons.

[0028] For steels used in cryogenic systems, low carbon content is most suitable.

[0029] This is due to the fact that carbon increases the upper threshold of cold brittleness, thereby expanding the temperature range of the steel's transition to a brittle state, which helps to increase the service life of the hinge joint.

[0030] Increasing the carbon content by 0.1% shifts the upper limit of this transition by approximately 20°C.

[0031] Also, face-centered cubic steel is not prone to brittle fracture at low temperatures, which increases the service life of the hinge joint.

[0032] When steel is alloyed with nickel, increasing its content to 10-15%, the brittleness temperature decreases steadily with an average rate of 20-30°C per 1% Ni. This is due to the fact that nickel weakens the interaction of dislocations with interstitial atoms and reduces the resistance of the crystal lattice to the movement of free dislocations, which increases the ductility and crack resistance of the steel, thereby increasing the service life of the hinge joint.

[0033] High nickel alloying is also done to prevent the formation of cooling martensite.

[0034] A chromium content of 16.5-18.5% or higher in steel is essential for the formation of a passive oxide film. This film, formed on the surface, provides protection against oxidation processes and corrosion, thereby increasing the overall corrosion resistance of the material, including in aggressive environments. Additionally, chromium contributes to a slight increase in the strength of the steel, which also contributes to a longer service life of the hinge joint.

[0035] The content of chromium and nickel stabilizes the austenite structure, which does not undergo phase transformations during cooling, which improves ductility and impact toughness, especially at low temperatures.

[0036] The addition of molybdenum increases the stability of supercooled austenite, which in turn reduces the cooling rate, eliminating the formation of ferrite.

[0037] An increase in the concentration of manganese in steel correlates with a decrease in the onset temperature of martensitic transformation and a decrease in tensile strength.

[0038] When complete stability of austenite is achieved, a further increase in the manganese content (more than 2%) does not lead to a change in strength characteristics.

[0039] In a preferred embodiment of the design, the steel has the following mechanical characteristics:

[0040] yield strength, MPa: 200;

[0041] tensile strength, MPa: 500-710;

[0042] KCV impact strength at 20°C, J / cm 2 : 100;

[0043] KCV impact strength at -196°C, J / cm 2 : 60.

[0044] The test results showed that steel with the specified mechanical characteristics increases the service life of the hinge joint.

[0045] The sleeve is installed in a hinge joint, which in one embodiment of the design includes a lower housing, which acts as a rotor, and an upper housing, which acts as a stator, wherein the sleeve in a preferred embodiment of the design includes projections with which the sleeve rests against the inner housing and is then pressed by flanges, which are attached to the housings using fasteners and press the projections of the sleeve.

[0046] The bushing can be secured in the hinge joint in various ways, for example, using a screw that passes through the inner housing of the hinge joint and is screwed into one of the protrusions of the bushing, which allows the bushing to be securely fixed in the hinge joint.

[0047] Using a bushing with the specified design features in a hinge joint can increase the service life of the hinge joint, especially when used in low-temperature environments.

[0048] BRIEF DESCRIPTION OF DRAWINGS

[0049] The claimed utility model is explained with illustrative material, where: Fig. 1 shows a general view illustrating a sleeve of a hinge joint; Fig. 2 shows a view illustrating a sleeve installed in a hinge joint.

[0050] The positions on the figures indicated are:

[0051] pos. 1 - bushing;

[0052] pos. 1.1 - bushing projection;

[0053] pos. 1.2 - screw;

[0054] pos. 2 - lower body;

[0055] pos. 3 - upper body;

[0056] pos. 4 - flange;

[0057] pos. 6 - fastening element.

[0058] IMPLEMENTATION OF A UTILITY MODEL

[0059] The claimed utility model is implemented as follows.

[0060] The sleeve 1 of the articulated joint is a cylindrical part that is installed in the articulated joint.

[0061] Sleeve 1 is made of low-carbon corrosion-resistant austenitic steel with a face-centered cubic crystal lattice and the content of the following alloying components that increase the steel's resistance to low temperatures, wt.%:

[0062] nickel - 10-15;

[0063] manganese - <2;

[0064] molybdenum - 2-2.5;

[0065] carbon - <0.07;

[0066] silicon - <1.0;

[0067] phosphorus - <0.045;

[0068] sulfur - <0.02;

[0069] chrome - 16.5-18.5;

[0070] nitrogen - <0.11;

[0071] hardware - everything else.

[0072] Bushing 1, made of steel with the specified chemical composition, is installed in the hinge joint during its assembly.

[0073] The sleeve is installed in a hinged joint, which in one embodiment of the design includes a lower housing 2, which acts as a rotor, and an upper housing 3, which acts as a stator, while the sleeve 1 in a preferred embodiment of the design includes projections 1.1, with which the sleeve rests against the inner housing 2 and is then pressed by flanges 4, which are attached to the housings with the help of fastening elements 5 and press the projections 1.1 of the sleeve 1.

[0074] The sleeve can be secured in the hinge joint in various ways, for example, using a screw 1.2, which passes through the inner housing of the hinge joint and is screwed into one of the protrusions 1.1 of the sleeve 1, which allows the sleeve to be securely fixed in the hinge joint.

[0075] The claimed utility model can be used in articulated joints operating at low temperatures.

Claims

1. A sleeve of a hinge joint, which is a cylindrical part, characterized in that it is made of low-carbon corrosion-resistant austenitic steel with a face-centered cubic crystal lattice and containing the following alloying components, wt.%: nickel 10-15 manganese <2 molybdenum 2-2,5 carbon <0,07 silicon <1,0 phosphorus <0,045 sulfur <0,02 chromium 16,5-18,5 nitrogen <0,11 iron everything else 2. The sleeve of the articulated joint according to paragraph 1, characterized in that the steel from which the sleeve is made has the following mechanical characteristics: yield strength, MPa: 200; tensile strength, MPa: 500-710; impact strength KCV at 20°C, J / cm 2 : 100; impact strength KCV at -196°C, J / cm 2 :

60.

3. The sleeve of the hinge joint according to item 1, characterized in that it is made with projections for installing the sleeve in the hinge joint.

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