CN113249561A

CN113249561A - Heat treatment method for ship stem casting

Info

Publication number: CN113249561A
Application number: CN202110597508.4A
Authority: CN
Inventors: 祝建楠; 蒋让文; 朱雨; 俞正江; 钱春俊
Original assignee: Shanghai Electric Shmp Casting & Forging Co ltd; Jiangnan Shipyard Group Co Ltd
Current assignee: Shanghai Electric Shmp Casting & Forging Co ltd; Jiangnan Shipyard Group Co Ltd
Priority date: 2021-05-31
Filing date: 2021-05-31
Publication date: 2021-08-13
Anticipated expiration: 2041-05-31
Also published as: CN113249561B

Abstract

The invention discloses a heat treatment method for a ship stem casting, which comprises the following steps: s1, attaching to the outer surface of the stem and arranging a reinforcing structure close to the opening side of the stem; s2, placing a plurality of auxiliary tools in the heat treatment furnace, matching the support end surfaces of the auxiliary tools with the surfaces of the corresponding stem side walls, and horizontally placing the stem on the auxiliary tools with one side wall facing downwards, the other side wall facing upwards and the opening side facing downwards; s3 placing appropriate weights above the stem for compaction. According to the invention, the reinforcing ribs and the T-shaped lacing bars are arranged on the side, close to the opening, of the stem casting, so that the structural strength of the casting is improved, the heat treatment deformation risk is reduced, effective support is provided for the stem by means of an auxiliary tool manufactured according to the surface of the stem, the heat treatment deformation of the stem is further avoided, and the manufacturing problem of size deformation in the heat treatment process of the stem is solved.

Description

Heat treatment method for ship stem casting

Technical Field

The invention relates to the field of ship manufacturing, in particular to a heat treatment method for a ship stem casting.

Background

The stem is the most front component of the hull head and is one of the most important components of the hull, the outer plate, the deck, the platform and the side longitudinal girders of the ship head are all finished at the stem, and the stem has the important functions of keeping the shape of the bow, gathering the outer plate and ensuring the strength of the bow. As shown in fig. 1 and 6, the stem has an overall structure of a long and thin rod shape similar to a C shape, and the cross section of the stem is generally V-shaped, that is, the stem includes two side walls and a rib structure located inside the two side walls, one side of the two side walls is connected to form a stem closed side, and the other side is not connected to form a stem opening side. Most of the stem has thin wall, complex shape and structure, poor integral rigidity and easy deformation in the heat treatment process. Therefore, it is necessary to provide a further solution to the above problems.

Disclosure of Invention

The invention aims to provide a heat treatment method for a ship stem casting, which overcomes the defects in the prior art.

In order to solve the technical problems, the technical scheme of the invention is as follows:

a heat treatment method for a ship stem casting comprises the following steps:

s1, attaching to the outer surface of the stem and arranging a reinforcing structure close to the opening side of the stem;

s2, placing a plurality of auxiliary tools in the heat treatment furnace, wherein the supporting end surfaces of the auxiliary tools are matched with the surfaces of the stem side walls corresponding to the auxiliary tools, and the stem is horizontally placed on the auxiliary tools with one side wall facing downwards, the other side wall facing upwards and the opening side facing downwards;

s3 placing appropriate weights above the stem for compaction.

In a preferred embodiment of the present invention, the S1 is attached to the outer surface of the stem and is provided with a reinforcing structure near the opening side thereof, specifically:

and reinforcing ribs are arranged on the outer surfaces of the middle sections respectively attached to the two side walls of the stem along the length direction of the stem, and T-shaped lacing wires are arranged on the two side walls of the stem respectively.

In a preferred embodiment of the invention, the total length of the supports of the auxiliary tools is not less than 1/10 of the stem length.

In a preferred embodiment of the invention, the distance between adjacent auxiliary tools is not more than 1.3 m.

In a preferred embodiment of the invention, at least two auxiliary tools are respectively arranged near the front end and the rear end of the stem.

In a preferred embodiment of the present invention, the supporting end surface of the auxiliary tool includes a limiting surface and a stopping surface, the limiting surface is matched with the surface of the non-opening side corresponding to the stem sidewall, and the stopping surface is matched with the surface of the opening side corresponding to the stem sidewall.

In a preferred embodiment of the present invention, the reinforcing rib and the T-shaped tie bar are integrally cast with the stem.

In a preferred embodiment of the present invention, the thickness of the reinforcing rib is 40% to 60% of the corresponding stem sidewall thickness.

In a preferred embodiment of the present invention, the thickness of the T-shaped tie bar is not less than 100 mm.

In a preferred embodiment of the present invention, the limiting surface extends from the center of the stem closed side to the stem opening side edge, and the stopping surface extends from the stem opening side edge close to the limiting surface to the stem opening side edge far from the limiting surface and protrudes a distance.

Compared with the prior art, the invention has the beneficial effects that:

according to the invention, the reinforcing ribs and the T-shaped lacing bars are arranged on the side, close to the opening, of the stem casting, so that the structural strength of the casting is improved, the heat treatment deformation risk is reduced, effective support is provided for the stem by means of an auxiliary tool manufactured according to the outer surface of the stem, the heat treatment deformation of the stem is further avoided, and the manufacturing problem of size deformation in the heat treatment process of the stem is solved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic structural view of a stem of a ship, in which (a) is a front view and (b) is a top view;

fig. 2 is a schematic structural view of an auxiliary tool, wherein (b) is a front view, and (a) and (c) are respectively two side sectional views;

FIG. 3 is a schematic front view of a stem with reinforcing ribs and T-shaped tie bars;

FIG. 4 is a schematic top view of a stem with T-shaped tie bars;

FIG. 5 is a schematic view of a stem viewed from above with an auxiliary tool;

fig. 6 is an enlarged partial cross-sectional view of the stem after installation.

Specifically, 10, stem; 11. a closed side; 12. an opening side; 13. side wall

20. Reinforcing ribs; 21. t-shaped lacing wires; 30. auxiliary tools; 31. a support end face; 311 a limiting surface; 312. a stop surface.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways than those specifically described herein, and therefore the scope of the present invention is not limited by the specific embodiments disclosed below.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on those shown in the drawings, and are used merely for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be taken as limiting the scope of the present invention. Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature. In the description of the invention, the meaning of "a plurality" is two or more unless otherwise specified.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art through specific situations.

As shown in fig. 1 and 6, the stem 10 has an overall structure of a slender rod shape like a C, and the cross section of the stem is overall V-shaped, that is, the stem 10 comprises two side walls 13 and a rib structure positioned inside the two side walls, one side of each side wall 13 is connected to form a closed side 11 of the stem 10, and the other side of each side wall is not connected to form an open side 12 of the stem 10.

As shown in fig. 2 to 6, a heat treatment method for a ship stem 10 casting comprises the following steps:

s1 conforms to the outer surface of the stem 10 and provides reinforcement near the open side 12 thereof.

The stem 10 has large cross sections at two end faces and small middle part, and the rest part is in smooth transition, namely the middle part is a thin neck part, so the stem is easy to deform.

The method specifically comprises the following steps: as shown in FIGS. 3 and 4, a reinforcing structure is provided adjacent to the open side 12 of the stem 10 to conform to the outer surface of the stem 10, and preferably, reinforcing ribs 20 are provided along the length of the stem 10 on the middle sides of the stem 10, i.e., on the sides of the narrow neck, i.e., on the outer surfaces of the middle sections of the side walls 13, to prevent the narrow neck from being deformed during the heat treatment process.

The reinforcing structure further includes two T-shaped tie bars 21 respectively disposed at the two side walls 13 to increase the overall structural strength of the stem 10 and prevent deformation. Specifically, two ends of the cross rod of the T-shaped tie bar 21 are respectively close to two ends of the stem 10, and the vertical rod is close to the center of the stem 10, so as to form a good shaping function and prevent the two ends from shrinking to the middle.

In general, the reinforcing rib 20 has a trapezoidal cross-sectional shape with a slope, and the thickness of the reinforcing rib is 40% to 60%, preferably 50%, of the wall thickness of the sidewall 13 of the stem 10 corresponding to the trapezoidal cross-sectional shape, so as to achieve a better strength increasing effect. In this embodiment, the thickness of the reinforcing rib 20 is 30-40 mm, wherein the upper opening is about 30mm, and the lower opening is about 40 mm. The thickness of the T-shaped lacing wire 21 is not less than 100 mm.

S2, placing a plurality of auxiliary tools 30 in the heat treatment furnace, matching the support end surface 31 of the auxiliary tool 30 with the corresponding surface of the side wall 13 of the stem 10, and horizontally placing the stem 10 on the plurality of auxiliary tools 30 with one side wall 13 facing downwards, the other side wall 13 facing upwards and the opening side 12 facing downwards.

It can be understood that when the auxiliary tool 30 is placed, the trolley of the heat treatment furnace is cleaned, the position of each auxiliary tool 30 is marked and positioned on the trolley by means of the tool position size template, the flame nozzle needs to be avoided at the tool position in the positioning process, so that deformation caused by uneven heating of the stem 10 is avoided, and the corresponding auxiliary tool 30 is placed at the designated position after the positioning is determined. The position of the cross section of the stem 10 is marked down, and the stem 10 is hung on the auxiliary tool 30 according to the mark.

As shown in fig. 5 and 6, the stem 10 is horizontally placed on the auxiliary fixtures 30 with one side wall 13 facing downward and the other side wall 13 facing upward, and the opening side 12 is horizontal, i.e. the symmetry plane of the stem 10 coincides with the horizontal plane, so that the stem 10 maintains better stability and reduces deformation during heat treatment. Meanwhile, the installation direction of the plurality of external auxiliary tools 30 is parallel to the direction of the internal reinforcing ribs 20, so that the supporting strength is further improved.

A plurality of auxiliary tools 30 are arranged according to the specific shape and size of the stem 10, and the plurality of auxiliary tools 30 are arranged below the side wall 13 of the stem 10 to evenly and stably support the stem 10 and avoid deformation in the heat treatment process. The support end surface 31 of the auxiliary tool 30 is shaped and sized according to the corresponding stem 10 section.

As shown in fig. 2 and 6, the support end surface 31 of the auxiliary fixture 30 includes a stopper surface 311 and a stopper surface 312, and the stopper surface 311 is used for cooperating with the non-open side 12 surface of the sidewall 13 of the stem 10 to support the stem 10, and preferably extends from the center of the closed side 11 of the stem 10 to the edge of the open side 12 of the stem 10. The stop surface 312 is adapted to cooperate with the surface of the open side 12 of the sidewall 13 of the stem 10, i.e. extends in the thickness direction of the stem 10, preferably extends from the edge of the open side 12 of the stem 10 close to the stop surface 311 to the edge of the open side 12 of the stem 10 away from the stop surface 311 and protrudes a distance, in this embodiment 100 mm. The stop surface 312 is used as an installation reference, i.e., the stop surface 312 is adjacent to the stem 10 when the stem 10 is placed, so as to prevent the stem 10 from sliding and dislocating when the stem is placed, and meanwhile, the limiting surface 311 and the stop surface 312 cooperate to limit the outward deformation of the closed side 11 to the open side 12 of the stem 10.

The auxiliary tool 30 is specifically made of a steel plate with the thickness of 80mm, a shaping sample plate is made according to the shape and the size of the cross section of the stem 10 at the position of the auxiliary tool 30, the support end surfaces 31 with the shape of the profiling line of the stem 10 with different positions and cross sections are made on two side surfaces of the steel plate with the thickness of 80mm by means of the shaping sample plate, as shown in A1, A1, A2 and A2 in the figure 4, the shapes of the support end surfaces 31 on two sides of the steel plate are polished, trimmed and smoothly transited, and then a plurality of steel plates with specific line shapes are spliced and welded into the auxiliary tool 30 to increase the area of the support end surfaces 31, so that the stem 10 is placed stably, and the structural strength of the auxiliary tool 30 is ensured.

More specifically, the support end surfaces 31 of at least two auxiliary fixtures 30 are respectively matched with the front and rear ends of the stem 10 to support the front and rear ends of the stem 10, so as to protect the front and rear ends which are easily deformed.

In this embodiment, as shown in fig. 5, four auxiliary tools 30 are provided, the four auxiliary tools 30 are provided along the length direction of the stem 10, two of the auxiliary tools 30 are respectively close to the front end and the rear end of the stem 10 to form a good support, and the rest auxiliary tools 30 are uniformly distributed in the middle of the stem 10.

The total support length of the auxiliary tools 30 is not less than 1/10 of the stem 10, and the distance between adjacent auxiliary tools 30 is not more than 1.3m, so that the stem 10 can be stably supported. The width of the single auxiliary tool 30 is not less than 300mm, and more preferably, is about 460 mm.

S3 is compacted by placing a suitable weight over stem 10 to prevent shrinkage.

Preferably, a heavy object is placed at the part of the stem 10 directly above the auxiliary tool 30 for compaction, specifically, the heavy objects with proper weight are respectively placed at the two ends and the middle part of the stem 10, the weight of the heavy objects is borne by other pressure-bearing structures, the weight of the heavy objects is prevented from being directly pressed on the stem 10, and the deformation of the stem 10 in the heat treatment process is limited by the heavy objects when the stem 10 deforms upwards, so that the heat treatment deformation of the stem 10 is reduced.

The S4 heat treatment process is carried out according to the conventional heat treatment process of the stem 10, and the temperature of the casting is uniformly raised and preserved, namely, the temperature is uniformly and continuously raised in the heat treatment process, so that all parameters are ensured to meet the process requirements.

In conclusion, the invention improves the structural strength of the casting and reduces the risk of heat treatment deformation by arranging the reinforcing ribs and the T-shaped lacing bars on the side wall 13 of the stem casting, provides effective support for the stem by means of the auxiliary tool manufactured according to the streamline type outside the stem, further avoids the heat treatment deformation of the stem, and solves the manufacturing problem of size deformation in the heat treatment process of the stem.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims

1. A heat treatment method for a ship stem casting is characterized by comprising the following steps:

s3 placing appropriate weights above the stem for compaction.

2. The heat treatment method for the ship stem casting according to claim 1, wherein the S1 is attached to the outer surface of the stem and is provided with a reinforcing structure near the opening side thereof, specifically:

3. The heat treatment method for the marine stem casting according to claim 1, wherein the total length of the supports of the auxiliary tools is not less than 1/10 of the stem length.

4. The heat treatment method for the ship stem casting according to claim 1, wherein the distance between every two adjacent auxiliary tools is not more than 1.3 m.

5. The heat treatment method for the ship stem casting according to claim 1, wherein at least two auxiliary tools are respectively arranged near the front end and the rear end of the stem.

6. The heat treatment method for the ship stem casting according to claim 1, wherein the support end surface of the auxiliary tool comprises a limiting surface and a stopping surface, the limiting surface is matched with the surface of the non-opening side corresponding to the stem sidewall, and the stopping surface is matched with the surface of the opening side corresponding to the stem sidewall.

7. The heat treatment method for the ship stem casting according to claim 2, wherein the reinforcing ribs and the T-shaped tie bars are integrally cast with the stem.

8. The heat treatment method for the ship stem casting according to claim 2, wherein the thickness of the reinforcing rib is 40% -60% of the corresponding wall thickness of the stem sidewall.

9. The heat treatment method for the ship stem casting according to claim 2, wherein the thickness of the T-shaped tie bar is not less than 100 mm.

10. The method of heat treating a marine stem casting of claim 6, wherein the stop face extends from the stem closure side center to the stem opening side edge and the stop face extends from the stem opening side edge proximate the stop face to the stem opening side edge distal from the stop face and projects a distance.