Inner cavity sand core for heat-resistant steel turbine shell

Abstract

The utility model relates to an inner cavity sand core for a heat-resistant steel turbine shell, which comprises an inner cavity sand core body, a chilling sand core is pre-buried on the inner cavity sand core body, and the position of the chilling sand core in the inner cavity sand core body corresponds to the tongue area of an upper runner of a turbine shell casting. In the process that the inner cavity sand core is used for pouring a heat-resistant steel turbine shell, a chilling sand core is pre-buried on the inner cavity sand core body corresponding to a runner tongue area on a turbine shell casting, the cooling speed of the casting can be remarkably increased through the chilling sand core, the tail end area of a volute casting hot spot is improved, and the casting quality is improved. Therefore, the problem of poor shrinkage of the tongue area of the runner on the inner cavity of the casting is solved.

Description

Technical Field

[0001] The utility model relates to the field of casting, in particular to an inner cavity sand core for a heat-resistant steel turbine shell. Background Art

[0002] like Figure 1 The heat-resistant steel turbine casing casting shown in the figure has a flow channel depression of about 30% during the inspection of the inner cavity of the turbine casing casting. There is no shrinkage compensation channel or shrinkage compensation source at the shrinkage area, and the casting forms shrinkage during the solidification process. Specifically, the shrinkage area of ​​this turbine casing casting is in the tongue area of ​​the flow channel on the volute. The main reason for the shrinkage is that the tongue area of ​​the flow channel on the volute is an isolated hot node area with no shrinkage compensation source. Summary of the invention

[0003] The technical problem to be solved by the utility model is: to overcome the deficiencies of the prior art, to provide an inner cavity sand core for a heat-resistant steel turbine shell, and to solve the technical problem that shrinkage depressions are formed in the tongue area of ​​the upper flow channel of the turbine shell casting during the casting process of the turbine shell casting caused by the inner cavity sand core in the past.

[0004] The technical solution adopted by the utility model to solve its technical problem is: to provide an inner cavity sand core for a heat-resistant steel turbine shell, which is characterized in that it includes an inner cavity sand core body, on which a quenching sand core is pre-embedded, and the position of the quenching sand core in the inner cavity sand core body corresponds to the upper flow channel tongue area of ​​the turbine shell casting.

[0005] Furthermore, the chilled sand core includes two molding surfaces, located at a first molding surface and a second molding surface respectively; the first molding surface faces the side where the turbine shell and the intermediate shell are assembled and installed; and the second molding surface faces the middle hole of the turbine shell.

[0006] Furthermore, the chilled sand core comprises three assembly surfaces, and the chilled sand core cooperates with the inner cavity sand core body via the three assembly surfaces.

[0007] The beneficial effect of the utility model is as follows: the utility model provides an inner cavity sand core for a heat-resistant steel turbine shell. When the inner cavity sand core is used to cast a heat-resistant steel turbine shell, a quenching sand core is pre-embedded on the inner cavity sand core body corresponding to the tongue area of ​​the upper flow channel of the turbine shell casting. The quenching sand core can significantly increase the cooling rate of the casting, improve the end area of ​​the hot node of the volute casting, and thus improve the poor shrinkage problem of the tongue area of ​​the upper flow channel of the inner cavity of the casting. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The utility model is further described below in conjunction with the accompanying drawings.

[0009] Figure 1 It is a schematic diagram of turbine casing casting; Figure 2 This is a schematic diagram of the inner cavity sand core for the heat-resistant steel turbine shell of the utility model; Figure 3This is a schematic diagram of the inner cavity sand core (without the chilled sand core) for the heat-resistant steel turbine shell of the utility model;

[0010] Figure 4 It is a schematic diagram of a chilled sand core; wherein, 1, turbine casing casting; 2, inner cavity sand core body; 21, give way groove; 3, chilled sand core; 31, first molding surface; 32, second molding surface; 33, assembly surface. DETAILED DESCRIPTION

[0011] In order to make the purpose, technical solution and advantages of the embodiments of the utility model clearer, the technical solution of the utility model will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0012] The present application provides an inner cavity sand core for a heat-resistant steel turbine shell, which is described in detail below. It should be noted that the description order of the following embodiments does not limit the preferred order of the embodiments of the present application. In the following embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0013] In order to solve the technical problem that the inner cavity sand core in the prior art forms a shrinkage depression in the tongue area of ​​the upper flow channel of the turbine casing casting 1 during the casting of the turbine casing casting 1, an embodiment of the present application provides an inner cavity sand core for a heat-resistant steel turbine casing, which is described in detail below.

[0014] like Figures 2 to 4 As shown, an inner cavity sand core for a heat-resistant steel turbine shell includes an inner cavity sand core body 2, on which a quenching sand core 3 is pre-embedded, and the position of the quenching sand core 3 in the inner cavity sand core body 2 corresponds to the upper flow channel tongue area of ​​the turbine shell casting 1.

[0015] Specifically, as an optional implementation in this embodiment, Figure 4 As shown, the chilled sand core 3 includes two molding surfaces, respectively located at a first molding surface 31 and a second molding surface 32; the first molding surface 31 faces the side where the turbine shell and the middle shell are assembled and installed; the second molding surface 32 faces the middle hole of the turbine shell.

[0016] In this embodiment, the second molding surface 32 is located on the concave arc surface.

[0017] Specifically, as an optional implementation in this embodiment, Figure 4As shown, the chilled sand core 3 includes three assembly surfaces 33 , and the chilled sand core 3 is matched with the inner cavity sand core body 2 via the three assembly surfaces 33 .

[0018] like Figure 2 As shown, a clearance groove 21 is formed on the inner cavity sand core body 2 , and the chilled sand core 3 cooperates with the clearance groove 21 . The clearance groove 21 has three inner wall surfaces to cooperate with the three assembly surfaces 33 of the chilled sand core 3 .

[0019] In this embodiment, the chilled sand core 3 mainly comprises chromite sand, the main chemical component of which is chromium oxide mineral (Cr2O3), accounting for more than 80% of the total mass, and in addition, it also contains a small amount of iron, aluminum, magnesium, calcium and other elements. The higher the chromium oxide content of the chromium ore sand, the higher the thermal conductivity of the chromium ore sand is than that of silica sand, which can significantly increase the cooling speed of the casting, and thus can play the role of an external chiller in practice.

[0020] The manufacturing process of the inner cavity sand core is as follows: first, a chilled sand core 3 is made, then, a make-away groove 21 is made in the sand core at the original process shrinkage position, and finally, the chilled sand core 3 is placed at the corresponding position.

[0021] The various devices selected in this application (components whose specific structures are not described) are all universal standard parts or components known to those skilled in the art, and their structures and principles can be known to those skilled in the art through technical manuals or conventional experimental methods.

[0022] In the description of the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0024] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, and the indirect coupling or communication connection of devices or units can be electrical, mechanical or other forms.

[0025] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0026] In addition, each functional unit in each embodiment of the present utility model may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0027] Based on the above ideal embodiments of the utility model, the relevant staff can make various changes and modifications without deviating from the technical concept of the utility model through the above description. The technical scope of the utility model is not limited to the content of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. An inner cavity sand core for a heat-resistant steel turbine shell, characterized in that: It comprises an inner cavity sand core body (2), a chilled sand core (3) being pre-embedded on the inner cavity sand core body (2), and the position of the chilled sand core (3) on the inner cavity sand core body (2) corresponds to the upper flow channel tongue area of ​​the turbine casing casting (1).

2. The inner cavity sand core for a heat-resistant steel turbine shell according to claim 1 is characterized in that: The chilled sand core (3) comprises two molding surfaces, located respectively on a first molding surface (31) and a second molding surface (32); The first molding surface (31) faces the side where the turbine shell and the intermediate shell are assembled and installed; and the second molding surface (32) faces the middle hole of the turbine shell.

3. The inner cavity sand core for a heat-resistant steel turbine shell according to claim 1 is characterized in that: The chilled sand core (3) comprises three assembly surfaces (33), and the chilled sand core (3) is matched with the inner cavity sand core body (2) via the three assembly surfaces (33).

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