Equipment and method for testing alloy crack sensitivity

Abstract

The invention belongs to the technical field of material performance detection, and particularly relates to alloy crack sensitivity testing equipment and method.The testing equipment comprises a heating casting system and a testing system which are arranged in the same sealed cabin; the heating casting system comprises a heating crucible, a stopper rod and a thermocouple; the thermocouple is arranged in the stopper rod; the testing system comprises a casting crucible and a copper plate; the casting crucible is located on the lower side of the heating crucible, and the copper plate is arranged at the bottom in the casting crucible. The thermocouple is arranged in the stopper rod, so that accurate temperature control can be realized; alloy oxidation is effectively prevented by controlling the atmosphere in the sealed cabin; the heating crucible and the casting crucible are both located in the sealed cabin, the casting process is rapid, stable and controllable, and the situation that the alloy temperature drop is too large during casting is avoided; and the alloy crack sensitivity can be accurately detected.

Description

Technical Field

[0001] The invention relates to the technical field of material performance detection, and in particular to a testing device and method for alloy crack sensitivity. Background Art

[0002] Hot cracking is the most common defect in the alloy production process, which seriously affects the smooth production of alloys and the quality and performance of alloys. With the thinning, diversified appearance and complex structure of casting designs, higher requirements are placed on the evaluation of alloy hot cracking sensitivity. There are several problems with the hot cracking sensitivity test of alloys reported in existing literature: First, the two processes of heating the alloy and casting are separate, which leads to a long casting process, a large temperature drop of the alloy melt and severe oxidation, affecting the accuracy of the test results. Second, the existing methods have high requirements on the fluidity of the alloy, and it is difficult for some alloys to complete the casting experiment. Third, although the existing alloy hot cracking sensitivity test method can evaluate the hot cracking sensitivity of the alloy, it does not conduct in-depth analysis for specific working conditions (for example, the wide surface of the slab continuous casting billet will produce cracks due to shrinkage during the solidification process). These methods are often carried out under standard experimental conditions and cannot fully reflect the actual production process. Summary of the invention

[0003] In order to solve the problems existing in the prior art, the main purpose of the present invention is to provide a testing device and method for alloy crack sensitivity.

[0004] According to one aspect of the present invention, the present invention provides the following technical solution: A testing device for alloy crack sensitivity, comprising: Heating casting system and testing system are installed in the same sealed cabin; The heating casting system includes a heating crucible, a stopper rod, and a thermocouple; the thermocouple is arranged in the stopper rod; The testing system comprises a casting crucible and a copper plate; the casting crucible is located at the lower side of the heating crucible, and the copper plate is arranged at the bottom of the casting crucible with a gap between the copper plate and the side wall of the casting crucible.

[0005] As a preferred solution of the alloy crack sensitivity testing equipment described in the present invention, a casting hole is provided at the bottom of the heating crucible to ensure that the alloy melt in the heating crucible flows out completely within 5 seconds, and the casting crucible is located at the lower side of the casting hole provided at the bottom of the heating crucible.

[0006] As a preferred embodiment of the alloy crack sensitivity testing device described in the present invention, the distance between the lower end of the casting hole arranged at the bottom of the heating crucible and the upper end of the copper plate does not exceed 300 mm.

[0007] As a preferred embodiment of the alloy crack sensitivity testing device described in the present invention, the device further comprises a stopper rod moving mechanism connected to the stopper rod and used to control the stopper rod position to realize the opening and closing control of the channel formed by the casting hole arranged at the bottom of the heating crucible by the stopper rod.

[0008] As a preferred embodiment of the alloy crack sensitivity testing device described in the present invention, the vertical central axes of the stopper rod, the heating crucible, the casting crucible and the copper plate coincide with each other.

[0009] As a preferred solution of the alloy crack sensitivity testing equipment described in the present invention, the heating crucible is heated by a circumferentially arranged heating induction coil.

[0010] As a preferred solution of the alloy crack sensitivity testing equipment described in the present invention, the equipment further comprises a vacuum machine and a gas source connected to the sealed cabin, for ensuring the vacuum atmosphere in the sealed cabin or maintaining the gas atmosphere in the sealed cabin.

[0011] As a preferred solution of the alloy crack sensitivity testing device described in the present invention, the device further comprises an observation window arranged on the sealed cabin shell for realizing observation inside the sealed cabin.

[0012] As a preferred solution of the alloy crack sensitivity testing equipment described in the present invention, the equipment further comprises a pressure gauge arranged outside the sealed cabin for indicating the pressure inside the sealed cabin.

[0013] As a preferred solution of the alloy crack sensitivity testing equipment described in the present invention, the equipment further comprises a water circulation machine connected to the heating induction coil, for cooling the heating induction coil.

[0014] As a preferred solution of the alloy crack sensitivity testing equipment described in the present invention, the equipment further comprises a control system for realizing operation adjustment and control of the equipment.

[0015] As a preferred solution of the alloy crack sensitivity testing equipment described in the present invention, the stopper rod can be made of high-temperature resistant materials such as corundum, magnesium oxide, zirconium oxide, boron nitride, etc.; the heating crucible can be made of high-temperature resistant materials such as corundum, magnesium oxide, zirconium oxide, etc.

[0016] According to another aspect of the present invention, the present invention provides the following technical solution: A method for testing alloy crack sensitivity comprises the following steps: S1. Place the alloy to be tested in a heating crucible, plug the casting hole of the heating crucible with a stopper rod, and place the casting crucible and the copper plate to ensure that the vertical axes of the stopper rod, the heating crucible, the casting crucible and the copper plate coincide with each other; S2, close the sealed cabin door, control the atmosphere in the sealed cabin, heat and melt the alloy to be tested and keep it warm, then move the stopper rod to make the alloy to be tested flow from the heating crucible into the casting crucible to complete the casting; S3. After the casting is completed, the alloy in the casting crucible is naturally cooled and then the casting is taken out. The cracks on the contact surface between the casting and the copper plate are counted, including the crack length and area. The crack sensitivity of the alloy is evaluated based on the crack length and area.

[0017] As a preferred embodiment of the method for testing crack sensitivity of an alloy described in the present invention, in which: in the step S3, under the same conditions of superheat, casting speed, copper plate and crucible size, the crack sensitivity of the casting process of the test material is judged according to the total length and area of ​​the cracks. The longer the total length of the cracks or the larger the total area, the higher the crack sensitivity of the casting process of the material.

[0018] The beneficial effects of the present invention are as follows: The present invention proposes a testing device and method for alloy crack sensitivity, the testing device includes a heating casting system and a testing system arranged in the same sealed cabin; the heating casting system includes a heating crucible, a stopper rod, and a thermocouple; the thermocouple is arranged in the stopper rod; the testing system includes a casting crucible and a copper plate; the casting crucible is located on the lower side of the heating crucible, and the copper plate is arranged at the bottom of the casting crucible. The stopper rod of the present invention has a built-in thermocouple, which can achieve precise temperature control; by controlling the atmosphere in the sealed cabin, the alloy oxidation can be effectively prevented; the heating crucible and the casting crucible are both in the sealed cabin, and the casting process is rapid, avoiding excessive temperature drop of the alloy during casting; the crack sensitivity of the alloy can be accurately detected, and the phenomenon of cracks generated by shrinkage on the wide surface of the ingot during solidification can be simulated. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0020] Figure 1 It is an analysis diagram of the stress conditions at the center of the wide surface and the center of the narrow surface of the ingot.

[0021] Figure 2 It is an analysis diagram of the stress conditions after casting the alloy melt in the test system.

[0022] Figure 3 It is a structural schematic diagram of the device of the present invention.

[0023] Figure 4 This is a picture of the casting obtained in Example 1.

[0024] Figure 5 This is a picture of the contact surface between the casting obtained in Example 1 and the copper plate.

[0025] Figure 6 This is a picture of the contact surface between the casting obtained in Example 2 and the copper plate.

[0026] Among them, 1-sealed cabin; 2-heating induction coil; 3-observation window; 4-heating crucible; 5-stopper rod; 6-stopper rod moving mechanism; 7-thermocouple; 8-pressure gauge; 9-control system; 10-casting platform; 11-casting crucible; 12-copper plate; 13-water circulation machine; 14-vacuum machine; 15-gas source.

[0027] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0028] The following will be described clearly and completely in conjunction with the technical solutions in the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] During slab continuous casting, the alloy melt enters the crystallizer and contacts the copper plate of the crystallizer, triggering heat exchange and starting the solidification process. As solidification and cooling proceed, the solidified shell gradually shrinks inward. However, due to the static pressure (F P ) effect, the wide face (WF) and narrow face (NF) of the ingot cannot shrink inwards, but can only shrink towards the center of each face, thus generating the wide face shrinkage stress (σ WF,s ) and narrow surface shrinkage stress (σ NF,s ). When the force in the direction of gravity is ignored, taking a quarter slice of the horizontal plane (XY plane) of the ingot as an example, during the process of the wide surface of the ingot shrinking toward the center of the surface, the shell of the narrow surface cannot move inward due to the static pressure of the alloy melt, which hinders the shrinkage of the wide surface. This hindering stress (σ NF,t,x ) and the contraction stress of the wide surface in the x direction (σ WF,s,x ) are equal, limiting the overall shrinkage of the wide surface. When the narrow surface shrinks inward, it is also subject to the obstruction stress (σ NF,s,y ), and the contraction stress of the narrow surface in the y direction (σ WF,t,y ) are the same. The stress conditions at the center of the wide face and the center of the narrow face of the ingot are as follows Figure 1 As shown ( Figure 1 The upper middle picture is a stereoscopic picture, and the lower picture is a wide cross-sectional view of the ingot). Figure 1 Medium, F P,yis the static pressure generated by the alloy melt in the Y direction; σ NF,t,x is the hindering stress generated by the narrow surface of the billet in the X direction; WF,s,x is the shrinkage stress generated on the wide surface of the billet in the X direction; WF,s,y is the shrinkage stress generated on the wide surface of the ingot in the Y direction; NF,s,y F is the shrinkage stress generated by the narrow surface of the billet in the Y direction; P,x is the static pressure generated by the alloy melt in the X direction; σ NF,s,x is the shrinkage stress generated on the narrow surface of the billet in the X direction; WF,t,y It is the hindering stress generated by the wide surface of the ingot in the Y direction. During the solidification process of the ingot, the shrinkage stress of the wide and narrow surfaces of the ingot is closely related to its horizontal length. Since the length of the wide surface is significantly greater than that of the narrow surface, its shrinkage stress and hindering stress also increase accordingly. Therefore, during the solidification process, the comprehensive stress experienced by the wide surface is significantly greater than that of the narrow surface. When the stress experienced by the wide surface exceeds the tensile strength of the ingot, cracks will occur on the wide surface.

[0030] In order to simulate the formation of surface cracks on the wide surface of the ingot during solidification and cooling in the crystallizer, the present invention designs a new test system, which consists of a casting crucible and a copper plate. Figure 2 The observation surface of the casting is the contact surface with the copper plate, as shown in Figure 2 The copper plate provides support at both ends of the casting in the test system. When the observation surface solidifies and shrinks inward, it is difficult to move due to the obstruction of the copper plate, resulting in shrinkage stress (σ s ) the same barrier stress (σ t ). When the combined stress of the observation surface exceeds the tensile strength of the alloy, cracks will form on the observation surface. This test system can effectively simulate the crack phenomenon caused by shrinkage on the wide surface of the ingot during solidification. By comparing the surface crack areas of the observation surface of different alloys under the same experimental conditions, the thermal crack sensitivity of the alloy can be evaluated, and the phenomenon of cracks caused by shrinkage on the wide surface of the ingot during solidification can be simulated.

[0031] like Figure 3 As shown, the present invention provides a testing device for alloy crack sensitivity, comprising: A heating casting system and a testing system are arranged in the same sealed cabin 1; The heating casting system includes a heating crucible 4, a stopper rod 5, and a thermocouple 7; the thermocouple 7 is arranged in the stopper rod 5; The test system is arranged on a casting platform 10 , and includes a casting crucible 11 and a copper plate 12 . The casting crucible 11 is located at the lower side of the heating crucible 4 , and the copper plate 12 is arranged at the bottom of the casting crucible 11 , with a gap between the copper plate 12 and the side wall of the casting crucible 11 .

[0032] Preferably, a casting hole is provided at the bottom of the heating crucible 4 to ensure that the alloy melt in the heating crucible 4 flows out completely within 5 seconds, and the casting crucible 11 is located at the lower side of the casting hole provided at the bottom of the heating crucible 4. Specifically, the diameter of the casting hole can be controlled at 8-28 mm, for example; Preferably, the distance between the lower end of the casting hole provided at the bottom of the heating crucible 4 and the upper end of the copper plate 12 does not exceed 300 mm.

[0033] Preferably, the device further comprises: a stopper rod moving mechanism 6, connected to the stopper rod 5, for controlling the position of the stopper rod 5, so as to realize the opening and closing control of the channel formed by the casting hole provided at the bottom of the heating crucible 4 by the stopper rod 5. Specifically, the diameter of the stopper rod can be controlled to be 10-30 mm and 2 mm larger than the casting hole, and the bottom end is chamfered to facilitate plugging the casting hole.

[0034] Preferably, the middle axes of the stopper rod 5, the heating crucible 4, the casting crucible 11 and the copper plate 12 in the vertical direction coincide with each other. Specifically, the inner dimensions of the casting crucible can be controlled, for example, to be 60-150 mm long, 40-100 mm wide, and 40-60 mm high, and the material can be high temperature impact resistant materials such as corundum, magnesium oxide, zirconium oxide, and steel. The dimensions of the copper plate can be controlled, for example, to be 50-140 mm long, 40-100 mm wide, and 5-20 mm high. By adjusting the heating system of the alloy to be tested, the dimensions of the casting crucible 11 and the copper plate 12, the crack sensitivity experiment of the alloy under different conditions can be completed. The copper plate 12 in the test system supports both ends of the casting. When the contact surface between the casting and the copper plate solidifies and shrinks inward, the two ends of the casting are difficult to move due to the obstruction of the copper plate 12, and an obstruction stress equal to the shrinkage stress is generated. When the stress generated at the contact surface between the casting and the copper plate is greater than its tensile strength, cracks will be generated on the contact surface between the casting and the copper plate, which can effectively simulate the phenomenon of cracks generated on the wide surface of the ingot due to shrinkage during the solidification process.

[0035] Preferably, the heating crucible 4 is heated by a circumferentially arranged heating induction coil 2 .

[0036] Preferably, the device further comprises: a vacuum machine 14 and a gas source 15 connected to the sealed cabin 1, for ensuring the vacuum atmosphere in the sealed cabin 1 or maintaining the gas atmosphere (such as argon atmosphere) in the sealed cabin.

[0037] Preferably, the device further comprises: an observation window 3 arranged on the shell of the sealed cabin 1 for realizing observation inside the sealed cabin 1 .

[0038] Preferably, the device further comprises: a pressure gauge 8 arranged outside the sealed cabin 1 for indicating the pressure inside the sealed cabin 1 .

[0039] Preferably, the device further comprises: a water circulation machine 13 connected to the heating induction coil 2 , for cooling the heating induction coil 2 .

[0040] Preferably, the device further comprises: a control system 9 connected to the heating induction coil 2, the stopper rod moving mechanism 6, the thermocouple 7, the pressure gauge 8, the water circulation machine 13, the vacuum machine 14, the gas source 15 (such as a gas cylinder), etc., for realizing operation adjustment and control of the device.

[0041] Preferably, the stopper rod 5 can be made of high temperature resistant materials such as corundum, magnesium oxide, zirconium oxide, boron nitride, etc.; the heating crucible 4 can be made of high temperature resistant materials such as corundum, magnesium oxide, zirconium oxide, etc.

[0042] The present invention also provides a method for testing alloy crack sensitivity, comprising the following steps: S1. Place the alloy to be tested in the heating crucible 4, plug the casting hole of the heating crucible 4 with the stopper rod 5, and place the casting crucible 11 and the copper plate 12, ensuring that the vertical central axes of the stopper rod 5, the heating crucible 4, the casting crucible 11 and the copper plate 12 coincide with each other; S2, close the door of the sealed cabin 1, control the atmosphere in the sealed cabin 1, heat and melt the alloy to be tested and keep it warm, then move the stopper rod 5 to make the alloy to be tested flow from the heating crucible 4 into the casting crucible 11 to complete the casting; S3. After the casting is completed, the alloy in the casting crucible 11 is naturally cooled and then the casting is taken out. The cracks on the contact surface between the casting and the copper plate 12 are counted, including the crack length and area. The crack sensitivity of the alloy is evaluated based on the crack length and area.

[0043] Preferably, in step S3, under the same conditions of superheat, casting speed, size of the copper plate 12 and the casting crucible 11, the crack sensitivity of the casting process of the test material is judged according to the total length and area of ​​the cracks. The longer the total length of the cracks or the larger the total area, the higher the crack sensitivity of the casting process of the material.

[0044] Preferably, in step S1, the amount of the alloy to be tested needs to be determined according to the specific sizes of the casting crucible 11 and the copper plate 12 to ensure that after the alloy flows into the casting crucible 11, a casting with a thickness of not less than 8 mm can be formed above the copper plate 12.

[0045] Preferably, in step S2, the door of the sealed cabin 1 is closed, the vacuum machine 14 is turned on, and the heating casting cabin is ensured to be in a vacuum environment. Then, it is decided whether to turn on the gas source 15 according to the experimental needs, and the heating system of the heating crucible 4 is set in the control system and the temperature is increased to heat, melt and keep the alloy to be tested warm.

[0046] Preferably, in step S2, the superheat of the alloy is controlled within a range of 30-200° C. according to the different alloys to be tested and the test requirements.

[0047] Preferably, in step S2, the control system 9 controls the power of the heating induction coil 2 in real time according to the data sent back by the thermocouple 7 to ensure accurate temperature control. After reaching the specified temperature, the stopper rod moving mechanism 6 is controlled by the control system 9 to lift the stopper rod 5, so that the alloy melt flows into the casting crucible 11 to complete the casting.

[0048] The technical solution of the present invention is further described below in conjunction with specific embodiments.

[0049] Example 1 A 2.005Cu-A1 alloy with a mass of 328g was placed in a heating crucible, and the stopper rod with a thermocouple was adjusted by the stopper rod moving mechanism to block the casting port of the heating crucible; the test system was arranged, and the internal dimensions of the casting crucible were: 110mm long, 60mm wide, and 50mm high; the dimensions of the copper plate were: 100mm long, 60mm wide, and 10mm high. The diameter of the stopper rod is 22mm, and the diameter of the casting port at the bottom of the heating crucible is 20mm. Ensure that the vertical central axes of the stopper rod, heating crucible, casting crucible and copper plate coincide, and the distance between the lower end of the casting hole set at the bottom of the heating crucible and the upper end of the copper plate is 200mm; turn on the vacuum machine, and after the heating and casting system is in vacuum, operate the control system to set the heating crucible heating rate to 50℃ / min, and enter the insulation stage after the temperature reaches 150℃; when the heating crucible completes the melting and insulation stage, the stopper rod moving mechanism is controlled by the control system to lift the stopper rod with a thermocouple, so that the alloy to be tested flows from the heating crucible into the casting crucible to complete the casting; after the casting is completed, the insulation is stopped by the control system, and the 2.005Cu-A1 alloy casting (such as Figure 4 As shown in the figure), the casting height is 25 mm, and the contact surface between the casting and the copper plate forms an observation surface as shown in the figure. Figure 5 According to statistics, the total length of the cracks in the casting is 91.29 mm and the area is 13.33 mm. 2 .

[0050] Example 2 A 4.1Cu-A1 alloy with a mass of 333g was placed in a heating crucible, and the stopper rod with a thermocouple was adjusted by the stopper rod moving mechanism to block the casting port of the heating crucible; the test system was arranged, and the internal dimensions of the casting crucible were: 110mm long, 60mm wide, and 50mm high; the dimensions of the copper plate were: 100mm long, 60mm wide, and 10mm high. The diameter of the stopper rod is 22mm, and the diameter of the casting port at the bottom of the heating crucible is 20mm. Ensure that the vertical central axes of the stopper rod, heating crucible, casting crucible and copper plate coincide, and the distance between the lower end of the casting hole set at the bottom of the heating crucible and the upper end of the copper plate is 200mm; turn on the vacuum machine, and after the heating and casting system is in vacuum, operate the control system to set the heating crucible heating rate to 50℃ / min, and enter the insulation stage after the temperature reaches 150℃; when the heating crucible completes the melting and insulation stage, the stopper rod moving mechanism is controlled by the control system to lift the stopper rod with a thermocouple, so that the alloy to be tested flows from the heating crucible into the casting crucible to complete the casting; after the casting is completed, the insulation is stopped by the control system, and the cast 4.1Cu-A1 alloy casting is taken out after natural cooling. The height of the casting is 25mm, and the observation surface formed by the contact surface between the casting and the copper plate is as shown in Figure 6 According to statistics, the total length of the cracks in the casting is 1.83mm and the area is 0.21mm. 2 .

[0051] It can be seen from Example 1 and Example 2 that increasing the copper content of the aluminum-copper alloy from 2.005wt% to 4.1wt% can significantly reduce the crack sensitivity of the aluminum-copper alloy.

[0052] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A testing device for alloy crack sensitivity, characterized in that: include: Heating casting system and testing system are installed in the same sealed cabin; The heating casting system includes a heating crucible, a stopper rod, and a thermocouple; the thermocouple is arranged in the stopper rod; The testing system comprises a casting crucible and a copper plate; the casting crucible is located at the lower side of the heating crucible, and the copper plate is arranged at the bottom of the casting crucible with a gap between the copper plate and the side wall of the casting crucible.

2. The alloy crack sensitivity testing equipment according to claim 1, characterized in that: A casting hole is arranged at the bottom of the heating crucible to ensure that the alloy melt in the heating crucible flows out completely within 5 seconds. The casting crucible is located at the lower side of the casting hole arranged at the bottom of the heating crucible.

3. The alloy crack sensitivity testing equipment according to claim 1, characterized in that: The device also includes a stopper rod moving mechanism connected to the stopper rod and used to control the position of the stopper rod to achieve the opening and closing control of the channel formed by the casting hole arranged at the bottom of the heating crucible by the stopper rod.

4. The alloy crack sensitivity testing equipment according to claim 1, characterized in that: The vertical central axes of the stopper rod, heating crucible, casting crucible and copper plate coincide with each other.

5. The alloy crack sensitivity testing equipment according to claim 1, characterized in that: The heating crucible is heated by a circumferentially arranged heating induction coil.

6. The alloy crack sensitivity testing equipment according to claim 1, characterized in that: The equipment also includes: a vacuum machine and a gas source connected to the sealed cabin, which are used to ensure the vacuum atmosphere in the sealed cabin or maintain the gas atmosphere in the sealed cabin.

7. The alloy crack sensitivity testing equipment according to claim 1, characterized in that: The device also includes: a pressure gauge arranged outside the sealed cabin, which is used to indicate the pressure inside the sealed cabin.

8. The alloy crack sensitivity testing equipment according to claim 1, characterized in that: The device also includes: a control system, which is used to implement operation adjustment control of the device.

9. The alloy crack sensitivity testing equipment according to claim 1, characterized in that: The stopper rod is made of high-temperature resistant materials including corundum, magnesium oxide, zirconium oxide and boron nitride; the heating crucible is made of high-temperature resistant materials including corundum, magnesium oxide and zirconium oxide.

10. A method for testing alloy crack sensitivity, using the alloy crack sensitivity testing device according to any one of claims 1 to 9, characterized in that: The steps include: S1. Place the alloy to be tested in a heating crucible, plug the casting hole of the heating crucible with a stopper rod, and place the casting crucible and the copper plate to ensure that the vertical axes of the stopper rod, the heating crucible, the casting crucible and the copper plate coincide with each other; S2, close the sealed cabin door, control the atmosphere in the sealed cabin, heat and melt the alloy to be tested and keep it warm, then move the stopper rod to make the alloy to be tested flow from the heating crucible into the casting crucible to complete the casting; S3. After the casting is completed, the alloy in the casting crucible is naturally cooled and then the casting is taken out. The cracks on the contact surface between the casting and the copper plate are counted, including the crack length and area. The crack sensitivity of the alloy is evaluated based on the crack length and area.

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