JP6552111B2 - Method for producing extruded shape of flame retardant magnesium alloy - Google Patents

Description

  The present invention relates to an extruded form of a flame-retardant magnesium alloy containing calcium, an assembly of a railway vehicle, and an assembly of transportation means.

  The conventional aluminum alloy profile is a hollow profile connecting a plurality of parallel flat plate-like face plates by a plurality of webs, and the hollow profile is integrally formed of an aluminum alloy (see, for example, reference 1). ). In such a conventional aluminum alloy shaped material, an equipment suspension holder for suspending the equipment is fixed to a notch of one face plate portion by a bolt.

Japanese Patent Laid-Open No. 2000-108899

  The conventional aluminum alloy profile has a double skin structure which is a composite structure in which the outer plate and columns of the vehicle body structure and the inner keying frame are integrated by connecting the two plate members by the core material. . For this reason, in the conventional aluminum alloy shaped material, when applied to a high-speed vehicle structure such as a Shinkansen vehicle, the weight of the truss-like core material portion increases, and there is a problem that weight reduction of the vehicle can not be achieved.

An object of the present invention is to provide a method for producing an extruded material of flame-retardant magnesium alloy whose weight can be reduced by using the flame-retardant magnesium alloy.

The present invention solves the above problems by means of solutions as described below.
In addition, although the code | symbol corresponding to embodiment of this invention is attached | subjected and demonstrated, it is not limited to this embodiment.
The invention of claim 1 is a method for producing an extruded shape of a flame retardant magnesium alloy containing calcium as shown in FIGS. 1 to 6 , wherein the flame retardant magnesium alloy is heated to a homogeneous heating temperature of 300 ° C. or higher. A homogenization treatment step (# 130) for homogenization treatment at 400 ° C. or less and a homogenization heating time of 5 hours or more and 10 hours or less, and the flame retardant magnesium alloy billet (B) after the homogenization treatment step An extruding step (# 140) of extruding into a ribbed shape while maintaining a temperature higher than the temperature at which the heat-resistant magnesium alloy is recrystallized at 350 ° C. or higher and 450 ° C. or lower , wherein the flame retardant magnesium alloy contains calcium. 0.5 mass% to 2.5 mass%, aluminum 2.0 mass% to 10.0 mass%, zinc 0.1 mass% to 1.5 mass%, manganese 0.1 mass% to 1.5 mass%, silicon 0.01 mass% to 0.1 mass% Hereinafter, iron and copper are each less than 0.002 mass%, The nickel containing less than 0.002%, a method for producing extruded shapes of flame-retardant magnesium alloy and the balance being magnesium (3) (# 100).

The invention of claim 2 is the method for producing extruded shapes of flame-retardant magnesium alloy according to claim 1, wherein the extrusion step is a step of extruding said flame retardant magnesium alloy in T rib profile It is a manufacturing method of the extrusion section of a flame-retardant magnesium alloy characterized by the above.

  According to the invention, the weight can be reduced by using a flame retardant magnesium alloy.

BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view which fractures | ruptures and shows one part of the structure of a traffic transportation means provided with the extrusion-shaped material of the flame-retardant magnesium alloy which concerns on embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is an external view of the extrusion-shaped material of the flame-retardant magnesium alloy which concerns on embodiment of this invention, (A) is a longitudinal cross-sectional view, (B) is sectional drawing which expands and shows the IIB part of (A). is there. It is a longitudinal cross-sectional view which shows the state which joined the extrusion shape of the flame-retardant magnesium alloy which concerns on embodiment of this invention by the junction part. It is an external view which shows the state which combined the extrusion-shaped material of the flame-retardant magnesium alloy which concerns on embodiment of this invention with frame, (A) is a top view, (B) is a front view, (C) Is a side view, and (D) is a cross-sectional view showing a state of being cut along the IV-IVD line of (A). It is process drawing of the manufacturing method of the extrusion-shaped material of the flame-retardant magnesium alloy which concerns on embodiment of this invention. It is a block diagram which shows typically the extrusion processing apparatus used for manufacture of the extrusion-shaped material of the flame-retardant magnesium alloy which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The transportation means 1 shown in FIG. 1 is a railway vehicle such as a train or a train. The structure 2 is the main structure of the traffic transportation means 1. As shown in FIG. 1, the structure 2 supports a weight of a passenger or a cargo and constitutes a floor portion or a frame of the vehicle body, and a floor structure 2a fixed to both edges of the floor structure 2a and a side surface portion of the vehicle body. A pair of side stands 2b, 2c to be constructed, a roof stand 2d which is fixed to the upper edges of the pair of side stands 2b, 2c and constitutes a roof portion of the vehicle body, and a wife stance not shown which constitutes both ends of the vehicle, etc. I have. The structure 2 includes an outer plate 3 shown in FIGS. 1 to 4 and a skeleton 4 shown in FIGS. 1 and 4. The structure 2 is a single skin structure in which a part of the frame 4 is integrated with the outer plate 3 to simplify the frame 4 and the manufacturing process, and realize a lightweight and low-cost structure.

  The outer plate 3 shown in FIGS. 1 to 4 is a member constituting a plate portion on the vehicle outer side of the structure 2. The outer plate 3 mainly constitutes the side mounts 2b and 2c of the structure 2 shown in FIG. The outer plate 3 shown in FIGS. 1 to 4 is an extruded shape of a calcium-containing flame-retardant magnesium alloy. In the outer plate 3, calcium is added to magnesium at the time of manufacture in order to ensure flame retardancy as a material property. The outer plate 3 is formed into a ribbed shape by an extrusion method. As shown in FIGS. 2 to 4, the outer plate 3 is formed into a T-shaped rib having a T-shaped cross section. The outer plate 3 includes a plate-like portion 3a shown in FIGS. 2 to 4, a rib portion 3b, a groove portion 3c shown in FIGS. 2 and 3, a joint portion 3d, and the like. As shown in FIGS. 2 and 3, the outer plate 3 is integrally formed with a plate-like portion 3a, a rib 3b and a groove 3c.

  The plate-like portion 3 a shown in FIGS. 2 to 4 is a portion that constitutes the main body of the outer plate 3. The plate-like portion 3a has flat surfaces parallel to each other. The rib part 3b is a part which provides rigidity to the plate-like part 3a. The rib 3b protrudes from one surface of the plate 3a and is integrally formed with the plate 3a. The rib portion 3 b is formed on the surface of the plate-like portion 3 a on the side to be the inner surface of the outer plate 3. The groove 3c shown in FIGS. 2 and 3 is a groove formed on the welding surface of the plate-like portion 3a in order to weld the plate-like portions 3a to each other. The groove 3c is a V-shaped groove formed at both ends in the longitudinal direction of the plate 3a at a predetermined inclination angle, and is integrally formed with the plate 3a. The joint portion 3d is a portion where the plate-like portions 3a are joined together. The joint portion 3d is a joint portion (welded joint) formed by butting end portions of the plate-like portion 3a with each other at the groove portion 3c and welding them. The joint portions 3d are formed at intervals in a direction orthogonal to the longitudinal direction of the plate-like portion 3a.

  The outer plate 3 shown in FIGS. 1 to 4 can not be reduced in weight when the thickness exceeds 10 mm, and is insufficient in strength when the thickness is less than 2 mm, so the thickness is preferably 2 mm or more and 10 mm or less . The outer plate 3 is assembled into the structure 2 by joining ends (joint surfaces) by, for example, friction stir welding (FSW), laser welding, TIG welding, or MIG welding. Be

  The flame retardant magnesium alloy is, for example, preferably a Mg-Al-Zn-Ca alloy or a Mg-Al-Mn-Ca alloy, and particularly preferably a Mg-Al-Zn-Ca alloy. Such flame retardant magnesium alloys include AZX 311 (Mg-3Al-Zn-Ca), AMX602 (Mg-6Al-Mn-2Ca), AZX611 (Mg-6Al-Zn-Ca), AZX612 (Mg-6Al-). Zn-2Ca) or AZX 911 (Mg-9Al-Zn-Ca) is preferred. If the content of calcium is less than 0.5 mass%, the flame retardant magnesium alloy can not exhibit sufficient flame retardancy effects, and if it exceeds 2.5 mass%, the flame retardancy is saturated and processing such as rolling is performed. It is preferable to contain calcium in an amount of 0.5 mass% or more and 2.5 mass% or less.

  If the content of aluminum is less than 2.0 mass%, the strength of the flame retardant magnesium alloy decreases, and if it exceeds 10.0 mass%, the amount of intermetallic compounds increases and the workability decreases, so 2.0 mass of aluminum is used. Preferably, it is contained in an amount of not less than% and not more than 10.0 mass%. Flame retardant magnesium alloy has low corrosion resistance, castability and plastic workability when the zinc content is less than 0.1 mass%, while arc weldability deteriorates when the zinc content exceeds 1.5 mass%. In order to reduce the effect, it is preferable to contain zinc in an amount of 0.1 mass% or more and 1.5 mass% or less. Flame retardant magnesium alloy, if the manganese content is less than 0.1 mass%, the corrosion resistance and castability will deteriorate, and if it exceeds 1.5 mass%, the workability will deteriorate, so manganese is 0.1 mass% or more and 1.5 mass% or less It is preferable to contain.

  The flame-retardant magnesium alloy preferably has a silicon content of 0.01 mass% or more and 0.1 mass% or less because the content of silicon exceeds 0.1 mass% to affect the strength as an impurity. The flame-retardant magnesium alloy has a problem of corrosion resistance when the content of each of iron and copper is 0.002 mass% or more, and therefore, it is preferable that each of iron and copper be less than 0.002 mass%. The flame retardant magnesium alloy has problems of corrosion resistance and weldability when the content of nickel is 0.002 mass% or more, and therefore, the content of nickel is preferably less than 0.002 mass%.

  The framework 4 shown in FIGS. 1 and 4 is a main member that constitutes the assembly 2 in combination with the outer plate 3. The frame 4 is disposed on the inner side (inside of the vehicle) of the outer plate 3 so as to be orthogonal to the outer plate 3 as shown in FIG. 1, and the length direction of the outer plate 3 as shown in FIGS. Are arranged at predetermined intervals. As shown in FIG. 4, the framework 4 is provided with a notch 4a in which both edges of the framework 4 are cut out so that the rib 3b of the outer plate 3 penetrates. The framework 4 has a substantially U-shaped cross section. The frame 4 is joined to the outer plate 3 by fillet welding the frame 4 and the outer plate 3 in a state where the rib 3b of the outer plate 3 penetrates the notch 4a. The framework 4 is, for example, an extruded shape obtained by forming a flame retardant magnesium alloy similar to the outer plate 3 by an extrusion method, or a shape obtained by forming a flame retardant magnesium alloy by a press forming method. An interior material or the like is attached to the frame 4 on the upper end surface of the frame 4.

Next, a method for producing an extruded shape of a flame retardant magnesium alloy according to an embodiment of the present invention will be described.
Manufacturing method # 100 shown in FIG. 5 is a method for manufacturing an extruded shape of the flame retardant magnesium alloy shown in FIGS. 1 and 2, and includes a heating and melting step # 110, a casting step # 120, and a homogenization treatment step. # 130, extrusion process # 140, and the like.

  The heating and melting step # 110 shown in FIG. 5 is a step of heating and melting a magnesium alloy and calcium. In the heating and melting step # 110, the Mg—Al—Zn-based magnesium alloy and calcium are heated and melted in a range of 600 to 750 ° C. in a vacuum or argon gas atmosphere.

  The casting step # 120 is a step of casting the molten metal of the magnesium alloy after the heating and melting step # 110. In the casting step # 120, in order to extrude the molten metal of the magnesium alloy after the heating and melting step # 110, the magnesium alloy is cast into a magnesium alloy ingot (metal lump) having a predetermined shape and size, and then the magnesium alloy is cast. The mass is rolled into small size magnesium alloy billets (cast billets) of square or round cross section.

  The homogenization treatment step # 130 heats the metal material to a predetermined temperature and holds it for a certain period of time so that the alloying elements of the metal material of the magnesium alloy after forging step # 120 are homogeneously distributed in the metal material. It is a process. In the homogenization treatment step # 130, the billet of the magnesium alloy after the forging step # 120 is heat-treated by homogeneous heating (homogenization treatment). In homogenization processing step # 130, there is a problem of insufficient homogenization if the temperature for homogeneous heating of magnesium alloy billets is below 300 ° C, and there is a problem of coarsening if it exceeds 400 ° C, so the temperature for homogeneous heating is Is preferably homogenized at 300 ° C. to 400 ° C. In addition, in homogenization process # 130, there is a problem of insufficient homogenization and segregation of alloying elements if the homogeneous heating time of magnesium alloy billet is less than 5 hours, and if it exceeds 10 hours, the problem of coarsening of crystal grains Because of this, it is preferable to homogenize the heating temperature for 5 hours or more and 10 hours or less.

  The extrusion processing apparatus 5 shown in FIG. 6 is an apparatus which extrudes a raw material to the metal mold | die of predetermined shape, and shape | molds the continuous body of predetermined cross-sectional shape. The extrusion apparatus 5 is a heat-resistant container 5a that heats and stores a billet (material) B of a flame-retardant magnesium alloy, and an extrusion having a predetermined cross-sectional shape while being attached to the outlet of the container 5a and passing the billet B. A die (die) 5b to be molded into the profile E, a ram (stem) 5c that pushes billet B in the container 5a toward the die 5b, and the container 5a is sandwiched between the billet B and the ram 5c. It has a dummy block 5d etc. which moves closely with the circumferential surface and moves with the ram 5c.

  The extrusion step # 140 shown in FIG. 5 is a step of extruding a calcium-containing flame-retardant magnesium alloy. The extrusion process # 140 is performed by applying pressure to the billet B of the flame retardant magnesium alloy after the homogenization process # 130 by the extrusion processing apparatus 5 shown in FIG. Process to In the extrusion step # 140, for example, the extruded shape E is obtained by direct extrusion (forward extrusion) in which the billet B of the flame retardant magnesium alloy after the homogenization step # 130 is placed in the container 5a and extruded toward the die 5b by the ram 5c. Is manufactured. In the extrusion step # 140, for example, in the case of hot extrusion, the flame retardancy after the homogenization treatment step # 130 so that work hardening is prevented and the billet B of the flame-retardant magnesium alloy passes easily through the die 5b. The billet B is maintained at a temperature (eg, 350 to 450 ° C.) higher than the temperature at which the magnesium alloy recrystallizes.

The extruded shape of the flame retardant magnesium alloy according to the embodiment of the present invention has the following effects.
(1) In this embodiment, the outer plate 3 is formed into a ribbed shape by an extrusion method of a flame retardant magnesium alloy. Therefore, by applying a ribbed shape of a flame-retardant magnesium alloy that is lighter than an aluminum alloy, it is possible to ensure flame retardancy while reducing the weight compared to the conventional hollow shape of an aluminum alloy. it can. Moreover, when applying to the transportation means 1, the weight of the structure 2 can be reduced by utilizing specific gravity of a flame-retardant magnesium alloy. For example, the weight can be reduced by up to about 20% compared to a conventional aluminum alloy structure.

(2) In this embodiment, the outer plate 3 is formed of a T-shaped rib of a flame retardant magnesium alloy. For this reason, it is possible to maintain the same strength and rigidity as the hollow section of the conventional aluminum alloy.

(3) In this embodiment, the flame retardant magnesium alloy is a Mg-Al-Zn-Ca alloy or a Mg-Al-Mn-Ca alloy. For this reason, a flame retardance can be improved compared with the conventional aluminum alloy.

  Next, an embodiment of the present invention will be described.

As the test material, an extruded shape of a flame retardant magnesium alloy according to the examples shown in Table 1 was used. The unit shown in Table 1 is mass percent.
Examples shown in Table 1 are plate materials obtained by molding a Mg-Al-Zn-Ca-based flame-retardant magnesium alloy (AZX611 (Mg-6Al-Zn-Ca)) to which calcium is added into a T-rib shape. In the embodiment, a magnesium alloy is heated by an electric furnace, and after the magnesium alloy is melted, 1.01 mass% of calcium is added and cast to produce a billet, and heated at a heating temperature of 300 to 400 ° C. for 5 to 10 hours to be homogeneous. After the crystallization treatment, it was produced by extruding with an extruder at a billet temperature of 430 ° C., an extrusion die temperature of 480 ° C., a container temperature of 425 ° C., and an extrusion product speed of 0.5 m / min.

(mechanical nature)

  The mechanical properties were confirmed for the examples. The proof stress, tensile strength and elongation shown in Table 2 are measured values when the test material of the example is measured according to JIS Z 2241 by a tensile test apparatus (Instron universal tester Model 4206). As a result, as shown in Table 2, it was confirmed that the examples were excellent in various properties of proof stress, tensile strength and elongation as in the conventional aluminum alloy profile.

The present invention is not limited to the embodiments described above, and various modifications or changes may be made as described below, which are also within the scope of the present invention.
(1) In this embodiment, the case where an extruded shape of a flame retardant magnesium alloy is applied to a railway vehicle is described as an example, but other transportation means such as an automobile, a ship, an aircraft, or a flying object are also described. The present invention can be applied. Moreover, in this embodiment, the case where the extruded shape of the flame retardant magnesium alloy is applied to the structure 2 of the railway vehicle has been described as an example. However, the floor material of the railway vehicle, the pantograph cover, the carriage closing plate, etc. The present invention can be applied.

(2) In this embodiment, although the case where a flame-retardant magnesium alloy was shape | molded to T rib shape was mentioned as an example and demonstrated, it can also be shape | molded to I shape material. In this embodiment, the case where the extruded shape E is manufactured by direct extrusion (forward extrusion) has been described as an example. However, the extruded shape is formed by indirect extrusion in which the billet is moved together with the container and extruded from a stationary mold. Can also be manufactured.

1 Transportation means (railcar)
2 Structure 3 Outer plate (extrusion profile)
3a Plate-shaped part 3b Rib part 3c Groove part 3d Joint part 4 Frame 4a Notch part 5 Extrusion apparatus 5a Container 5b Die 5c Ram 5d Dummy block B Billet E Extrusion shape

Claims (2)

What is claimed is: 1. A method for producing an extruded form of flame-retardant magnesium alloy containing calcium, comprising:
A homogenization treatment step of homogenizing the flame retardant magnesium alloy at a homogeneous heating temperature of 300 ° C. to 400 ° C. and a homogeneous heating time of 5 hours to 10 hours;
Extrusion in which the billet of the flame retardant magnesium alloy after the homogenization treatment process is extruded into a ribbed shape while maintaining a temperature higher than 350 ° C. and lower than 450 ° C. above the temperature at which the flame retardant magnesium alloy recrystallizes. Process,
The flame-retardant magnesium alloy is 0.5 mass% to 2.5 mass% calcium, 2.0 mass% to 10.0 mass% aluminum, 0.1 mass% to 1.5 mass% zinc, 0.1 mass% to 1.5 mass% manganese , 0.01mass% or more and 0.1mass% or less of silicon, less than 0.002mass% iron and copper respectively, less than 0.002mass% nickel, the balance being magnesium,
A method for producing an extruded material of flame-retardant magnesium alloy characterized by In the method for producing an extruded material of a flame retardant magnesium alloy according to claim 1,
Said extruding step is a step of extruding said flame retardant magnesium alloy in T rib profile,
A method for producing an extruded material of flame-retardant magnesium alloy characterized by

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