JPH048140B2 - - Google Patents

Description

[Detailed description of the invention]

A. Object of the invention (1) Industrial application field The present invention relates to a mold casting method. (2) Conventional technology Conventionally, it is known that a mold casting method is used in which a temperature gradient is applied to the mold, thereby aiming at directional solidification, but no consideration has been given to the timing of releasing the casting. No (see Utility Model Application Publication No. 61-82746). (3) Problems to be solved by the invention When casting a casting using a mold to improve its productivity, due to the high thermal conductivity of the mold, the shape of the casting, etc. The solidification shrinkage rate is rapidly accelerated in some parts, and a part of the casting is restrained by the mold, resulting in hot cracking of the casting.
There is a problem that damage such as deformation and wear occurs in the mold. In view of the above, the present invention provides a highly productive method capable of releasing a casting before hot cracking occurs, thereby obtaining a sound casting and avoiding damage to a mold due to solidification shrinkage of the casting. The purpose is to provide a mold casting method. B. Structure of the Invention (1) Means for Solving the Problems The present invention provides a method in which a cavity forming part that forms a casting cavity of a mold and a molten metal path forming part that forms a molten metal path such as a sprue and a runner are preheated. In response to the pouring operation, cooling of the cavity forming part is started to change the surface layer of the casting formed by the cavity into a shell-like solidified layer, and upon completion of the pouring operation, the molten metal is After starting the cooling of the channel forming part and solidifying the unnecessary part formed by the molten metal channel, a mold release operation is performed, and then when the temperature of the cavity forming part and the molten metal channel forming part falls to near the preheating temperature. stop cooling them,
After that, the temperature of the cavity forming part and the molten metal channel forming part is restored to the preheating temperature. (2) Effects As described above, if the cavity forming part and the molten metal path forming part are preheated and pouring work is performed, and the cooling of the molten metal path forming part is started upon completion of the pouring work,
It is possible to avoid occurrence of casting defects such as poor hot water circulation. In addition, when cooling of the cavity forming part is started in accordance with the pouring operation, the surface layer of the casting is rapidly cooled and turned into a shell-like solidified layer, and unnecessary parts are solidified due to the cooling operation of the molten metal channel forming part. As a result, the casting can be reliably released from the mold together with unnecessary parts within a short time after pouring is started. The casting thus obtained did not suffer from hot cracking, nor did it cause any damage to the mold. Furthermore, since the casting is covered with a shell-like solidified layer, it will not deform during demolding. Thereafter, when the temperatures of the cavity forming section and the molten metal path forming section drop to near the preheating temperature, cooling of both forming sections is stopped, and the temperature of both forming sections can be recovered to the preheating temperature within a short time. When the cavity forming part and the molten metal path forming part are cooled in this way and the surface layer of the casting changes to a solidified layer, the mold is released, and after the mold release, the preheating temperature recovery operation of both forming parts is performed as described above. The time required for one casting operation can be significantly shortened compared to the conventional die casting method, which requires waiting for complete solidification of the casting, thereby improving the productivity of the casting. (3) Embodiment Casting of cast iron castings FIGS. 1 to 3 show a mold casting apparatus M1 equipped with a mold 1, and the apparatus M1 is configured to cast a plurality of cam parts 2a as cast iron castings shown in FIG. The camshaft 2 is used to cast a camshaft 2 having a plurality of shaft portions (including a journal) 2b. Mold 1 is made of Cu containing 0.8 to 4% by weight of Cr.
-Constructed from Cr alloy, its thermal conductivity is 0.4 ~
It is 0.8 cal/cm/s/℃. The mold 1 is divided into two parts, _a first mold 1 ₁ and a second mold _{1 2} . A molding cavity 6 and a gas vent hole 7 are each defined. First to third preheating mechanisms _H1 to H3 and first to third cooling mechanisms C1 to C for the first and second molds 1 1 and 1 ₂
3 and knockout means 8, which are substantially the same for both molds 1 ₁ and 1 ₂ , so the first mold 1 ₁ will be described. The first preheating mechanism H1 includes a heater ₁₀ 1 disposed in each first area 9 1 forming each cam part forming area 6 a in the cavity forming part ₉ of the first mold ₁ 1 .
and a first preheating temperature controller Ch1 connected to each heater ₁₀₁ . The second preheating mechanism H2 includes heaters 10 ₂ disposed in each second area 9 ₂ forming each shaft molding region 6b in the cavity forming section 9, and each heater 1
0 ₂ and a second preheating temperature controller Ch2 connected to the temperature controller Ch2. The third preheating mechanism H3 includes a sprue 3 of the first mold ₁₁ ,
It includes a plurality of heaters ₁₀₃ disposed in a molten metal path forming section 11 forming a molten metal path _P1 consisting of a runner 4 and a gate 5, and a third preheating temperature controller Ch3 connected to each heater ₁₀₃ . There is. The first cooling mechanism C1 includes a cooling water channel 12 ₁ extending to each first section 9 ₁ in the cavity forming part 9 of the first mold 1 ₁ and a first cooling temperature controller connected to each cooling water channel 12 ₁ . It is equipped with Cc1. The second cooling mechanism C2 includes a cooling water channel 1 extending to each second area ₉₂ in the cavity forming part 9.
2 ₂ and a second cooling temperature controller Cc2 connected to each cooling water channel 12 ₂ . The third cooling mechanism C3 includes a plurality of cooling channels 12 ₃ extending to the molten metal channel forming section 11 of the first mold 1 ₁ ,
A third cooling temperature controller Cc3 connected to each cooling water channel 12 ₃ is provided. The knockout means 8 includes a plurality of pins 13, a support plate 14 supporting one end of the pins 13, and an actuating member 15 connected to the support plate 14, each pin 13 being formed in the first mold _{11 and} connected to the sprue. 3. It is slidably fitted into each insertion hole 16 that opens into the runner 4 and the cavity 6. In the cavity 6, the opening of each insertion hole 16 is arranged in the shaft molding region 6b. Next, the camshaft 2 by the mold casting device M1 is
The casting process will be explained. First, a molten metal having a cast iron component equivalent to JIS FC20 to FC30 shown in the table is prepared.

[Table] The cast iron is in the diagonally shaded component range _A1 in the Fe-C system equilibrium diagram in Figure 5, and the eutectic line Le
1 intersects the component range _A1 at approximately 1150°C. 0.15% by weight of Fe--Si is added to the molten metal so that the camshaft 2 has the composition shown in the table.

[Table] As shown in FIG. 6, the mold 1 is preheated by each preheating mechanism H1 to H3 prior to pouring, and each first area ₉₁ forming each cam part forming area 6a is aligned with the line _X1. As shown by point _a1 , the temperature is approximately 70°C, and each second area ₉₂ forming each shaft molding area 6b is a line.
The temperature _is about 120 _° C as shown by _point b ₁ on line
Each is maintained at ℃. The molten metal after inoculation is poured into the mold 1 at a temperature of 1380 to 1420°C, and the camshaft 2 is cast. The casting weight at this time was 5 kg. Preheating the mold 1 as described above improves the flowability of the molten metal during pouring and prevents poor running of the molten metal.
Furthermore, cracks in the camshaft 2 caused by rapid cooling of the molten metal can be avoided. As shown by _{point a1 on} line Each cam part 2
Achieve chilling of a. Also, as shown by point _c2 on line _X3 in Figure 6, the third cooling mechanism C3 is activated at the same time as the pouring operation is completed
Start cooling the molten metal path forming part 11 and form the molten metal path P ₁
The rapid solidification of the molten metal existing in the process is started and the solidified state is achieved at an early stage. Furthermore, as shown by point b _{2 on} line X ₂ in FIG.
When the second cooling mechanism C2 is reached, the second cooling mechanism C2 is activated to start cooling each second zone ₉₂ and rapidly cool the molten metal existing in each shaft forming region 6b. In FIG. 7, the surface layer of the camshaft 2 is rapidly cooled by the cooling effect, and when the surface layer temperature drops to about 1150°C (eutectic line Le1) shown at point _d1 ,
The camshaft 2 enters a solidified state, and its surface layer turns into a shell-like solidified layer. In this case, if the surface temperature falls below 700°C as indicated by point _d5 , there is a risk that hot cracking will occur in the camshaft 2. Furthermore, if the surface temperature falls below 800°C as indicated by point _d4 , the camshaft 2 may come into close contact with the mold 1 due to solidification and contraction of the camshaft 2, causing damage such as deformation and wear to the mold 1. There is a risk that this may occur. Therefore, when the surface temperature of the camshaft 2 reaches 850°C as shown at point _d3 from 950°C as indicated by point _d2 about 3 to 8 seconds after pouring, and as shown in FIG. The temperatures of 9 ₁ , 9 ₂ , 11 are points a ₂ −a ₃ and points
b ₃ - b ₄ and points c ₃ - _{c 4} , the mold is opened and the knockout means 8 is operated to remove the camshaft 2.
Then, the unnecessary parts formed by the molten metal path _P1 are released from the mold. Thereafter, in FIG _. 6, the temperature in _the first zone ₉₁ reaches approximately 75°C, as shown by _{point a4} on _the line omitted
125℃, and the temperature of the molten metal path forming part 11 is
When the temperature drops to approximately 115°C as _{indicated by point c5} of
stop cooling. Even after the start of pouring work, the first to third preheating mechanisms H1 to
H3 is in the operating state and the first and second zones 9 ₁ ,
9 ₂ and the molten metal path forming section 11 are temperature controlled as indicated by lines X ₁ to X ₃ . Therefore, after the cooling is stopped, the temperature of the first and second areas 9 ₁ , 9 ₂ and the molten metal path forming section 11 is controlled as shown by lines X 1 to X 3 . The temperature immediately returns to the preheat temperature, which allows the next casting operation to begin. The camshaft 2 obtained by the above method did not suffer from hot cracking, and the mold 1 did not suffer any damage. Moreover, since the camshaft 2 is covered with a shell-like solidified layer, it will not be deformed during demolding. Furthermore, since each first area ₉₁ is cooled at the same time as the pouring operation starts, each cam part forming area 6
The molten metal present in a is rapidly cooled, and thereby each cam portion 2a can be reliably chilled. FIG. 8a is a micrograph (100 times magnified) showing the metal structure of the cam portion 2a, and FIG. 8b is a micrograph (100 times magnified) showing the metal structure of the shaft portion 2b. From FIG. 8a, white elongated crystals of cementite are observed in the structure of the cam portion 2a, and it is clear that the structure is chilled. As described above, when the cavity forming part 9 and the molten metal channel forming part 11 are cooled and the surface layer of the camshaft 2 becomes a solidified layer, the mold is released, and after the mold release, the preheating temperature recovery operation of both the molding parts 9 and 11 is performed. If this method is used, one casting operation can be carried out in an extremely short time of about 28 seconds, as is clear from FIG. 6, thereby making it possible to improve productivity. The optimum release range for cast iron castings made of cast iron equivalent to JIS FC to FC30 is when the surface temperature is approximately 1150°C.
~800℃, therefore 350℃ directly below the eutectic line Le1
However, as a result of experiments, it has been found that the same can be said for cast iron castings using other cast irons such as spheroidal graphite cast iron. Note that the cooling operation is performed according to lines X ₂ and X ₃ in the case of a casting that does not have a chill section. Casting of Steel Castings FIGS. 9 to 11 show a mold casting device M2 equipped with a mold 101, and the device M2 has a camshaft having the same shape as the camshaft 2 shown in FIG. 4 as a steel casting. Used for casting. The mold 101 is made of the same Cu-Cr alloy as described above. The mold 101 is a first mold 101 ₁
and the second type 101 ₂ , which is divided into two parts,
The mating surfaces of the first and second molds 101 ₁ and 101 ₂ form a sprue 103, a runner 104, and a gate
5. A camshaft molding cavity 106 and a gas vent hole 107 are defined respectively. The first and second molds 101 ₁ and 101 ₂ have first and second preheating mechanisms H1 and H2;
Cooling mechanisms C1, C2 and knockout means 108 are provided, which are connected to both molds 101.
Since it is the same for ₁ , 101 ₂ , the first type 10
1 I will explain about ₁ . The first preheating mechanism H1 includes a plurality of heaters 110 ₁ arranged in the cavity forming part 109 of the first mold 101 ₁ and a first preheating mechanism H1 connected to each heater 110 ₁ .
It is equipped with a preheating temperature controller Ch1. The second preheating mechanism H2 includes a molten metal channel forming section 11 of the first mold ₁₀₁₁ that forms a molten metal channel _P2 consisting of a sprue 103, a runner 104, and a gate 105.
a plurality of heaters 110 ₂ arranged in 1, and a second preheating temperature controller connected to each heater 110 ₂
It is equipped with Ch2. The first cooling mechanism C1 includes a plurality of cooling channels 112 ₁ extending to the cavity forming part 109 of the first mold 101 ₁ and a first cooling temperature controller Cc1 connected to each cooling channel 112 ₁ . There is. The second cooling mechanism C2 includes a plurality of cooling channels 1 extending in the molten metal channel forming section ₁₁₁ of the first mold 1011.
12 ₂ and a second connected to each cooling water channel 112 ₂
It is equipped with a cooling temperature controller Cc2. The knockout means 108 includes a plurality of pins 11.
3. A support plate 118 supporting one end of the pins 113 and an actuating member 115 connected to the support plate 114, each pin 113 having a first type 1
01 ₁ formed with sprue 103 and runner 104
and each insertion hole 1 opening into the cavity 106
16 so as to be slidable. Next, the camshaft 2 by the mold casting device M2 is
The casting process will be explained. As the main charging raw materials, 50 to 70% by weight of scrap material (steel) and 50 to 60% by weight of return material are charged into a high frequency melting furnace and melted, and C,
Alloy tool steel (JIS SKD-11) shown in the table with the addition of auxiliary materials such as Fe-Cr, Fe-Mo, Fe-V, etc.
Prepare molten steel with a corresponding alloy cast steel composition.

[Table] The alloy cast steel is in the diagonally shaded component range _A2 in the Fe-C system equilibrium state diagram in FIG. 5, and the solidus line Ls intersects the component range _A2 at approximately 1250°C. The temperature of molten steel is raised in an inert gas atmosphere such as argon gas, and 0.2% by weight of Ca-
Primary deoxidation with addition of Si and at 1650-1670℃
Secondary deoxidation is performed by adding 0.1% by weight of Al. As shown in FIG. 12, the mold 101 is preheated by both preheating mechanisms _H1 and _H2 prior to pouring the molten metal. Path forming part 11
1 is maintained at approximately 110° C., as shown by point f ₁ on line Y ₂ . Deoxidized molten steel is poured into this mold 101 at a temperature of 1,630 to 1,670°C, and a camshaft is cast. The casting weight at this time was 5.0 kg. If the mold 101 is preheated as described above,
It is possible to improve the flowability of the molten metal during pouring, and to avoid cracks in the camshaft caused by rapid cooling of the molten steel. As shown by point f ₂ on line Y ₂ in Fig. 12, the second cooling mechanism C2 is operated at the same time as the pouring operation is completed, and cooling of the molten metal channel forming section 111 is started to rapidly cool the molten metal existing in the molten metal channel P ₂ . Initiates solid coagulation and achieves a coagulated state at an early stage. Further, as shown at point e ₂ of the line Y ₁ in FIG. Cooling is started and the molten metal existing in the cavity 106 is rapidly cooled. In FIG. 13, the surface layer of the camshaft is rapidly cooled by the cooling action, and the temperature of the surface layer is at point g ₁
When the temperature drops to about 1250℃ (solidus line Ls),
The camshaft enters a solidified state, and its surface layer turns into a shell-like solidified layer. In this case, if the surface temperature falls below 950°C as indicated by point _g5 , there is a risk of hot cracking occurring in the camshaft. Furthermore, when the surface temperature falls below 1000°C as indicated by point g ₄ , the camshaft rapidly solidifies and shrinks, causing the camshaft to adhere to the mold 101, causing deformation, wear, etc. in the mold 101. There is a risk that the condition may occur. Therefore, when the surface temperature of the camshaft reaches 1100°C as shown at point _g3 from about 3.5 to about 6.3 seconds after pouring _, and in FIG. The temperature of 109,111 is point e ₃ −
e ₄ , when the point is in the range of f ₃ − f ₄ , open the mold,
The knock-out means 108 is operated to release the unnecessary parts formed by the camshaft and the molten metal path _P2 . Thereafter, in FIG. 12, the temperature of the cavity forming part 109 is approximately 150°C as shown by point _e5 on line _Y1 .
℃, and the temperature of the molten metal path forming part 111 is the line Y ₂
When the temperature drops to approximately 140℃ as shown at point f ₅ ,
The operation of each of the cooling mechanisms C1 and C2 is stopped to stop cooling the cavity forming section 109 and the molten metal channel forming section 111. The first and second preheating mechanisms H remain active even after pouring work has started.
1, H2 is in the operating state and both forming portions 109,
111 is temperature controlled as shown by lines Y ₁ and Y ₂ ,
Therefore, after the cooling is stopped, the temperatures of both forming portions 109 and 111 immediately return to the preheating temperature, and the next casting operation can then be started. The camshaft obtained by the above method did not suffer from hot cracking, and the mold 101 did not suffer any damage. Furthermore, since the camshaft is covered with a shell-like solidified layer, it will not deform during mold release. The optimum release range for a steel casting made of the above-mentioned alloy cast steel is when its surface temperature is approximately 1250 to 1000°C, therefore between the solidus line Ls and 250°C directly below it, but as a result of experiments, It has been found that the same holds true for ordinary cast steel. The charged raw materials are not limited to those equivalent to the alloy tool steel, but include scrap materials and return materials as the main raw materials, and C, Ni,
Those prepared by adding alloying elements such as Cr, Mo, V, Co, T, Si, Al, etc. singly or in combination so as to contain 0.4 to 1.8% by weight of C are used. Casting of Aluminum Alloy Casting The above-mentioned steel casting mold casting apparatus M2 is used to cast a camshaft as an aluminum alloy casting. For casting work, first of all, as shown in the table,
Prepare a molten metal with an aluminum alloy component equivalent to JIS ADC12.

[Table] The aluminum alloy shown in Fig. 14 is Al-
In the Si system equilibrium phase diagram, it is in the diagonally shaded component range _A3 , and the eutectic line Le2 intersects the component range _A3 at 580°C. As shown in FIG. 15, the mold 101 is preheated by both preheating mechanisms _H1 and _H2 prior to pouring the molten metal. Path forming part 11
1 is maintained at approximately 110° C., as shown by point n ₁ on line Z ₂ . Molten aluminum alloy is poured into the mold 101 at a temperature of 700 to 740°C to cast a camshaft. The casting weight at this time was 2.0Kg. If the mold 101 is preheated as described above,
It is possible to improve the flowability of the molten metal during pouring, and to avoid cracking of the camshaft caused by rapid cooling of the molten metal. As shown by point _n2 on line _Z2 in Fig. 15, the second cooling mechanism C2 is activated at the same time as the pouring operation is completed, and cooling of the molten metal channel forming section 111 is started to rapidly cool the molten metal existing in the molten metal channel _P2 . This causes solid coagulation to begin and achieve a coagulated state at an early stage. Further, as shown by point _m2 on line _Z1 in FIG. The molten metal existing in the cavity 106 is rapidly cooled. In FIG. 16, the surface layer of the camshaft is rapidly cooled by the cooling effect, and when the surface temperature drops to approximately 580°C (eutectic line Le2) shown at point _p1 ,
The camshaft enters a solidified state, and its surface layer turns into a shell-like solidified layer. In this case, if the surface temperature falls below 280°C as indicated by point _p4 , there is a risk that hot cracking will occur in the camshaft. Furthermore, if the surface temperature falls below 350°C as indicated by point _p3 , the camshaft will adhere tightly to the mold 101 due to rapid and large solidification contraction of the camshaft, causing melting damage to the mold 101. may cause damage. Therefore, approximately 3.0 to 10.8 seconds after pouring,
When the surface temperature of the camshaft reaches 500°C as indicated by point _p2 , and in FIG.
When the temperature of 9,111 is in the range of points m ₃ -m ₄ and points n ₃ -n ₄ , the mold is opened and the knock-out means 108 is activated to remove the unnecessary part formed by the camshaft and the molten metal path P ₂ . Release from the mold. In FIG. 15, the cavity forming part 109
to approximately 125 °C, as shown by point m ₅ on line Z ₁ ,
Further, when the temperature of the molten metal channel forming section 111 drops to approximately 115° C. as indicated by point _n5 of the line _Z2 , the operation of each cooling mechanism C1, C2 is stopped, and the cavity forming section 109 and the molten metal channel forming section 111 are stopped. stop cooling. The first and second preheating mechanisms H remain active even after the start of molten metal work.
1, H2 is in the operating state and both forming portions 109,
111 is temperature controlled as shown by lines Z ₁ and Z ₂ ,
Therefore, after the cooling is stopped, both forming portions 1
The temperature at 09,111 immediately returns to the preheating temperature, allowing the next casting operation to begin. The camshaft obtained by the above method did not suffer from hot cracking, and the mold 101 did not suffer any damage. Furthermore, since the camshaft is covered with a shell-like solidified layer, it will not deform during mold release. The optimum mold release range for castings made of the above alloy is that the surface temperature is approximately 580 to 350°C, and therefore the eutectic line
This is when the temperature is between Le2 and 230°C directly below Le2, but experiments have shown that the same holds true for aluminum alloys such as Al-Cu and Al-Zn. Note that cooling of the cavity forming portions 9, 109 may be started before the pouring operation is finished, and cooling of the molten metal channel forming portions 11, 111 may be started immediately after the pouring operation is finished. The present invention is applicable not only to camshafts but also to the casting of various mechanical parts such as crankshafts, brake calipers, and knuckle arms. C. Effects of the Invention According to the present invention, by performing the cooling operation as described above, the surface layer of the casting is made into a shell-like solidified layer, and the unnecessary parts formed by the molten metal channel are rapidly solidified, and in this state, they are separated. Since molding is performed, the work can be performed reliably during mold release, and the shape-retaining ability of the solidified layer can be obtained to obtain sound castings, as well as to prevent damage to the mold and extend its life. In addition, by performing the mold release operation and preheating temperature recovery operation as described above, the time required for one casting operation is reduced.
Compared to the conventional die casting method, which requires waiting for complete solidification of the casting, the time required for casting can be significantly reduced, thereby improving the productivity of the casting.

[Brief explanation of drawings]

1 to 3 show a camshaft mold casting device for cast iron castings, FIG. 1 is an overall perspective view, FIG. 2 is a view taken from FIG. - Line sectional view, Figure 4 is a front view of the camshaft, Figure 5 is a Fe-C system equilibrium state diagram, and Figure 6 is a camshaft as a cast iron casting, elapsed time from the start of pouring and mold temperature. Figure 7 is a graph showing the relationship between the elapsed time after pouring and the surface temperature of the camshaft for a camshaft as a cast iron casting, and Figure 8 is a graph showing the relationship between the surface temperature of the camshaft as a cast iron casting. Micrographs showing the structure, FIGS. 9 to 11 show a camshaft mold casting device as a steel casting, FIG. 9 is a perspective view of the whole, and FIG. 10 is a view taken from FIG. Figure 11 is a cross-sectional view taken along the line XI-XI in Figure 10, Figure 12 is a graph showing the relationship between the elapsed time from the start of pouring and mold temperature for a camshaft as a steel casting, and Figure 13 is a graph showing the relationship between the time elapsed from the start of pouring and the mold temperature as a steel casting. Graph showing the relationship between the elapsed time after pouring and the surface temperature of the camshaft for the camshaft.
Figure 4 is an equilibrium state diagram of the Al-Si system, Figure 15 is a graph showing the relationship between the elapsed time from the start of pouring and mold temperature for a camshaft as an aluminum alloy casting, and Figure 16 is a graph showing the relationship between the elapsed time from the start of pouring and the mold temperature as an aluminum alloy casting. 2 is a graph showing the relationship between the elapsed time after pouring and the surface temperature of the camshaft in the camshaft of FIG. C1 to C3...first to third cooling mechanisms, H1 to H
3...first to third preheating mechanisms, _P1 , _P2 ...molten metal path,
1,101... Mold, 2... Camshaft as casting, 3,103... Sprue, 4,104... Runner, 6,106... Cavity, 9,109...
Cavity forming part, 11, 111... Molten metal channel forming part.

Claims (1)

[Scope of Claims] 1. Pouring the metal in a state where the cavity forming part forming the casting cavity of the mold and the molten metal path forming part forming the molten metal path such as a sprue and runner are preheated,
In response to the pouring operation, cooling of the cavity forming section is started to change the surface layer of the casting formed by the cavity into a shell-like solidified layer, and upon completion of the pouring operation, cooling of the molten metal channel forming section is started. After solidifying the unnecessary parts formed by the molten metal channel, a mold release operation is performed, and then, when the temperature of the cavity forming part and the molten metal channel forming part drops to near the preheating temperature, cooling them is stopped, A mold casting method characterized in that the temperature of the cavity forming part and the molten metal channel forming part is then restored to the preheating temperature. 2. The casting is a cast iron casting, and the mold release is performed when the surface temperature of the cast iron casting is 350°C between and directly below the eutectic line.
Claim 1 that occurs when there is a
Mold casting method described in section. 3. The mold casting according to claim 1, wherein the casting is a steel casting, and the mold release is performed when the surface temperature of the steel casting is between a solidus line and 250° C. directly below the solidus line. Law. 4. The metal casting according to claim 1, wherein the casting is an aluminum alloy casting, and the mold release is performed when the surface temperature of the aluminum alloy casting is between a eutectic line and 230° C. directly below the eutectic line. Mold casting method.