A flame cutting process for making large frame castings based on wide-thick continuous casting billets

Abstract

The application belongs to the technical field of metal casting processing, and particularly provides a flame cutting process for manufacturing large frame castings based on wide-thick continuous casting billets, S1, pretreatment; S2, selecting cutting gas, adjusting the selected gas to form stable cutting flame; S3, determining the optimal cutting path and cutting speed; S4, cutting the pretreated wide-thick continuous casting billets to obtain casting billets; S5, cooling the casting billets; S6, deburring and surface treatment of the cooled casting billets; S7, detecting the casting blank. The application solves the problems of unstable cutting, excessively large heat-affected zone and poor cutting surface quality in the conventional gas flame cutting process of wide-thick continuous casting billets due to the large thickness of the billets. The application reduces the excessive oxidation and overheating phenomenon in the cutting process, improves the cutting precision and the quality of the cutting surface, and meets the requirements of large frame structure castings in precision, strength and surface quality.

Description

Technical Field

[0001] This invention belongs to the field of metal casting processing technology, specifically relating to a flame cutting process for manufacturing large frame castings based on thick continuous casting billets. Background Technology

[0002] With the development of modern industry, especially the increasing demand from sectors such as heavy machinery, transportation, energy, and aerospace, large frame structure castings have become crucial in equipment manufacturing. Thick and wide continuously cast billets, due to their large cross-sections and good consistency, have gradually become the raw material for large castings. However, during the processing of thick and wide continuously cast billets, their large size, heavy weight, high surface quality requirements, and difficulty in controlling the heat-affected zone easily lead to low cutting efficiency, severe tool wear, rough cut surfaces, cracks, and other defects on the billet surface, affecting the subsequent processing and performance of the casting blank. Gas flame cutting technology, with its simple operation, low cost, and good cutting effect, has been widely used in the steel industry. However, in the cutting of thick and wide continuously cast billets, due to the large billet thickness, conventional gas flame cutting methods often suffer from unstable cutting, excessively large heat-affected zones, and poor cut surface quality. Therefore, how to improve cutting accuracy and efficiency and reduce the heat-affected zone has become a pressing technical challenge in this field.

[0003] Chinese patent CN117773053A discloses a method for manufacturing defect-free high-Ni steel continuous casting billets. The steps include: selecting a slab continuous casting machine → casting in a tundish → water-cooled crystallizer → billet pulling → strong cooling with gas mist → weak cooling with gas mist in the bending section → weak cooling with gas mist in the arc section → weak cooling in the straightening section → the continuously cast billet after flame cutting enters the cooling bed. Beneficial effects: It solves the problems of surface cracks and internal quality issues that are prone to occur in high-Ni steel billets. The basic feature of this patent is the analysis of the plastic temperature zone and phase transformation temperature characteristics during the cooling process of Ni-containing steel. By controlling the cooling water volume in the crystallizer and the secondary cooling section, the temperature at the crystallizer outlet and the surface of the bent billet during continuous casting is further reduced, the reheating rate in the arc section is controlled, stress is reduced, and the surface and internal quality of the billet are improved. However, this patent also fails to address the problems that conventional gas flame cutting methods often suffer from instability, excessive heat-affected zones, and poor cut surface quality during the cutting of thick continuously cast billets due to their large thickness. Summary of the Invention

[0004] The present invention provides a flame cutting process for manufacturing large frame castings based on thick continuous casting billets. The purpose is to overcome the problems of unstable cutting, excessive heat-affected zone, and poor cutting surface quality that often occur in conventional gas flame cutting methods during the cutting of thick continuous casting billets due to the large billet thickness.

[0005] Therefore, the present invention provides a flame cutting process for manufacturing large frame castings based on thick continuous casting billets, comprising the following steps: S1. Pre-treat the surface of the thick continuous casting billet to make the surface of the thick continuous casting billet meet the required standards; S2. Select the cutting gas and adjust the selected gas to form a stable cutting flame; S3. Determine the optimal cutting path and cutting speed; S4. Use a stable cutting flame and cut the pretreated wide and thick continuous casting billet according to the optimal cutting path and cutting speed. S5. Cool the cut, thick continuous casting billet. S6. Deburr and surface treatment are performed on the thick continuous casting billet after cooling. S7. Inspect the thick continuous casting billet after deburring and surface treatment. The thick continuous casting billet that passes the inspection is the finished casting.

[0006] Preferably, the selected gas is a mixture of oxygen and a combustible gas, wherein the combustible gas is acetylene or propane.

[0007] Preferably, the volume ratio of acetylene to oxygen is 1:1.1-1.3, and the volume ratio of propyne to oxygen is 1:1.2-1.4.

[0008] Preferably, step S3 uses an intelligent algorithm to determine the optimal cutting path and cutting speed.

[0009] Preferably, the intelligent algorithm includes ant colony optimization, genetic algorithm, and particle swarm optimization algorithm.

[0010] Preferably, the cutting speed is 0.5-2 mm / s.

[0011] Preferably, the cutting of the pretreated thick continuous casting billet includes a preheating stage and a cutting stage; the preheating stage involves heating the pretreated thick continuous casting billet to the target temperature; the cutting stage involves cutting the heated thick continuous casting billet until the cutting is completed.

[0012] Preferably, the target temperature range is 500-800℃.

[0013] Preferably, during the cutting process in step S4, a real-time feedback flame focus adjustment device is used to monitor and adjust the flame focus.

[0014] Preferably, the cooling process employs spray cooling.

[0015] The beneficial effects of this invention are: 1. The flame cutting process for manufacturing large frame castings based on thick continuous casting billets provided by this invention includes the following steps: S1. Pre-treating the surface of the thick continuous casting billet to achieve the required standard; S2. Selecting a cutting gas and adjusting it to form a stable cutting flame; S3. Determining the optimal cutting path and cutting speed; S4. Using a stable cutting flame, cutting the pre-treated thick continuous casting billet according to the optimal cutting path and cutting speed; S5. Cooling the cut thick continuous casting billet; S6. Deburring and surface treating the cooled thick continuous casting billet; S7. Inspecting the deburred and surface-treated thick continuous casting billet, and the qualified thick continuous casting billet is the finished casting. This invention solves the problems of traditional cutting methods when processing thick blanks by selecting cutting gas, adjusting the selected gas to form a stable cutting flame, determining the optimal cutting path and cutting speed, and cooling, deburring, and surface treating the casting blank. It reduces excessive oxidation and overheating during the cutting process, significantly improves cutting accuracy and the quality of the cut surface, reduces the number of reworks caused by uneven cutting, increases production efficiency, and reduces production costs. It can meet the requirements of large frame structure castings in terms of accuracy, strength, and surface quality.

[0016] 2. The flame cutting process for making large frame castings based on thick continuous casting billets provided by this invention uses a mixture of oxygen and combustible gas, wherein the combustible gas is acetylene or propane. Oxygen provides high temperature, and acetylene or propane provides combustion energy, so that the flame can reach a sufficient temperature and can quickly melt and blow away the metal in the cutting area.

[0017] 3. The flame cutting process for producing large frame castings based on thick continuous casting billets provided by this invention uses intelligent algorithms to determine the optimal cutting path and cutting speed. It can plan the shortest path and avoid irregular cutting in complex workpiece shapes and irregular contours, thereby improving the overall cutting efficiency.

[0018] 4. The flame cutting process for producing large frame castings based on thick continuous casting billets provided by this invention uses spray cooling to quickly reduce the temperature and ensure the quality of the casting billet. Attached Figure Description

[0019] The present invention will now be described in further detail with reference to the accompanying drawings.

[0020] Figure 1 This is a schematic diagram of the flame cutting process for manufacturing large frame castings based on thick continuous casting billets. Detailed Implementation

[0021] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are for illustrative purposes only and are not intended to limit the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer should be followed. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0022] Example 1: A flame cutting process for fabricating large frame castings from thick continuous casting billets includes the following steps: S1. Pre-treat the surface of the thick continuous casting billet to make the surface of the thick continuous casting billet meet the required standards; Specifically, before gas flame cutting, the surface of the thick continuous casting billet needs to be pretreated to ensure that there are no serious defects such as oxides, impurities, or cracks. Pretreatment of the thick continuous casting billet can improve the cutting quality.

[0023] S2. Select the cutting gas and adjust the selected gas to form a stable cutting flame; S3. Determine the optimal cutting path and cutting speed; S4. Use a stable cutting flame and cut the pretreated wide and thick continuous casting billet according to the optimal cutting path and cutting speed. S5. Cool the cut, thick continuous casting billet. S6. Deburr and surface treatment are performed on the thick continuous casting billet after cooling. S7. Inspect the thick continuous casting billet after deburring and surface treatment. The thick continuous casting billet that passes the inspection is the finished casting.

[0024] This invention solves the problems of traditional cutting methods when processing thick billets by selecting cutting gas, adjusting the selected gas to form a stable cutting flame, determining the optimal cutting path and cutting speed, cooling the cut thick continuous casting billet, deburring and surface treating it. It reduces excessive oxidation and overheating during the cutting process, significantly improves cutting accuracy and the quality of the cut surface, reduces the number of reworks caused by uneven cutting, increases production efficiency, and reduces production costs. It can meet the requirements of large frame structure castings in terms of accuracy, strength and surface quality.

[0025] Example 2: Based on Example 1, the selected gas is a mixture of oxygen and a combustible gas, wherein the combustible gas is acetylene or propane.

[0026] Specifically, oxygen provides the high temperature, while acetylene or propane provides the combustion energy. By adjusting the gas flow and pressure, a stable and high-temperature flame is formed, ensuring the efficiency of the cutting process and the quality of the cut surface.

[0027] Preferably, the volume ratio of acetylene to oxygen is 1:1.1-1.3, and the volume ratio of propyne to oxygen is 1:1.2-1.4.

[0028] Specifically, the mixed gas with this ratio can easily form a stable cutting flame, with a cutting temperature of over 3000°C, and can quickly melt and blow away the metal in the cutting area.

[0029] Preferably, the selected gas flow rate is regulated by a gas flow control valve to adjust the flow rates of oxygen and combustible gas. This facilitates the formation of the desired cutting flame.

[0030] Example 3: Based on Example 2, step S3 uses an intelligent algorithm to determine the optimal cutting path and cutting speed.

[0031] Specifically, by employing intelligent algorithms to determine the optimal cutting path and speed, the system can plan the shortest path and avoid irregular cutting in complex workpiece shapes and irregular contours, thus preventing deformation caused by continuous large-area cutting. Based on the thickness and shape of the casting blank, the cutting feed angle is adjusted to optimize the cutting trajectory, ensuring the straightness and precision of the cut surface and improving overall cutting efficiency.

[0032] Preferably, the intelligent algorithm includes ant colony optimization, genetic algorithm, and particle swarm optimization algorithm.

[0033] Specifically, ant colony optimization (ACO), genetic algorithm, and particle swarm optimization (PSO) can quickly and accurately calculate the optimal cutting path. These algorithms are all existing technologies. Based on the actual shape and size of the wide and thick continuously cast billet, the cutting feed angle and path are optimized, making the cutting process smoother and more precise. This avoids irregular cutting and multiple adjustments required by traditional methods, thus improving overall cutting efficiency.

[0034] Preferably, the cutting speed is 0.5-2 mm / s.

[0035] Specifically, a cutting speed of 0.5-2 mm / s ensures stable cutting and good cutting quality.

[0036] Example 4: Based on Example 3, the cutting of the pretreated thick continuous casting billet includes a preheating stage and a cutting stage; the preheating stage involves heating the pretreated thick continuous casting billet to the target temperature; the cutting stage involves cutting the heated thick continuous casting billet until the cutting is completed.

[0037] Specifically, by heating the pretreated, thick continuously cast billet to the target temperature, thermal stress and cracks that may occur during the cutting process are reduced. Once the surface of the thick continuously cast billet reaches the target temperature, oxygen is introduced into the selected gas flame to react with the metal, generating iron oxide which carries away the metal, thus completing the cutting.

[0038] Preferably, the preheating stage involves uniformly heating the pretreated wide and thick continuous casting billet to the target temperature.

[0039] Specifically, the surface of the thick continuous casting billet is heated evenly during the preheating process to prevent excessive temperature differences. By heating the billet surface evenly, the cutting instability caused by temperature differences is reduced, and the risk of cracks caused by temperature differences is lowered.

[0040] Preferably, the target temperature range is 500-800℃.

[0041] Specifically, before cutting, the surface of the thick continuous casting billet is preheated, with the temperature controlled between 500-800℃. By uniformly heating the billet surface, the cutting instability caused by temperature difference is reduced, and the risk of cracks caused by temperature difference is lowered.

[0042] Preferably, the heating is performed using a gas combustion heater or a resistance heating furnace. This method is easy to operate and has low cost.

[0043] Example 5: Based on Example 4, during the cutting process in step S4, a real-time feedback flame focus adjustment device is used to monitor and adjust the flame focus.

[0044] Specifically, during the cutting process, an existing real-time feedback flame focus adjustment device is used. High-precision sensors monitor the temperature distribution and material condition of the cutting area in real time, automatically adjusting the position of the flame focus and gas flow rate to keep the flame in optimal cutting condition, greatly improving the stability and accuracy of the cutting process. Simultaneously, precise adjustment of gas flow rate and cutting speed ensures uniformity and stability in the cutting process, preventing overheating or material damage in the cutting area.

[0045] Preferably, during the cutting process, a dynamic thermal monitoring device is also used to monitor the surface temperature and thermal gradient of the wide and thick continuous casting billet in real time, and combined with an adaptive algorithm, to intelligently adjust the gas flow rate and cutting speed.

[0046] Specifically, the dynamic thermal monitoring device is an existing device that incorporates dynamic thermal monitoring technology to monitor the surface temperature and thermal gradient of the wide and thick continuously cast billet in real time. Combined with an adaptive algorithm, it intelligently adjusts the gas flow rate and cutting speed to ensure uniform heat input distribution. This effectively prevents localized overheating and defects such as cracks and deformation caused by excessive temperature differences.

[0047] Example 6: Based on Example 5, the cooling process employs spray cooling.

[0048] Specifically, after cutting, a high-temperature zone will appear in the heat-affected zone of the casting blank, which can easily lead to stress concentration and surface hardening. The temperature can be quickly reduced by means of spray cooling or water cooling to ensure the quality of the casting blank.

[0049] After cutting, the surface of the casting blank may have some oxide scale and irregularities. To improve surface quality and dimensional accuracy, further processing is carried out through subsequent machining (such as grinding, deburring, etc.) to ensure that the blank meets the requirements of subsequent processing. After cutting, necessary post-processing is performed, including removing oxides and impurities from the cutting area to ensure that the cut surface is smooth and flat.

[0050] Preferably, the spray cooling is performed using a water spray device.

[0051] Specifically, cooling is achieved through a water spray device, and the spray water flow rate and cooling speed are controlled to reduce thermal stress.

[0052] Preferably, the deburring is performed using mechanical polishing or electrolytic polishing. This method provides excellent deburring results, ensuring a smooth, burr-free cut surface and further improving its flatness and smoothness, thus laying the foundation for subsequent processing and use.

[0053] Preferably, when inspecting the casting blank, the inspection methods include ultrasonic testing, laser measurement, and visual inspection.

[0054] Specifically, cutting accuracy is checked using ultrasonic testing, laser measurement, and visual inspection to ensure that the quality of the casting blanks meets standard requirements. Surface roughness is measured using a surface roughness meter.

[0055] Example 7: Based on Example 6, a flame cutting device for producing large frame structure casting blanks from thick continuous casting billets includes: Temperature-controlled heating equipment is used to preheat the surface of wide and thick continuously cast billets before cutting; Flame cutting machine, used for flame cutting of wide and thick continuously cast billets; An adjustable gas supply device is used to supply the required gas to the flame cutting machine; Cooling device, used to cool the cut wide and thick continuous casting billet; The quality inspection device is used to inspect the thick continuous casting billets after deburring and surface treatment.

[0056] Preferably, the flame cutting machine can automatically adjust the feed speed and cutting path to adapt to wide and thick continuous casting billets of different shapes and thicknesses.

[0057] Preferably, the cooling device includes a water spray device; it can automatically adjust the spray water flow rate according to the size and temperature of the cut casting blank, with a water flow rate range of 10L / min to 200L / min. When the casting temperature exceeds 500°C, the water spray flow rate automatically increases, and the adjustment response time of the water spray device does not exceed 3 seconds.

[0058] The present invention has the following advantages: 1. Improved cutting accuracy: By optimizing cutting parameters and controlling gas flow, excessive oxidation and overheating during the cutting process are reduced, significantly improving cutting accuracy and the quality of the cut surface.

[0059] 2. Improved production efficiency: Optimized cutting parameters and process sequence increase cutting speed and reduce rework caused by uneven cutting, thereby improving production efficiency and reducing production costs.

[0060] 3. Suitable for wide and thick continuous casting billets: This process is particularly suitable for wide and thick continuous casting billets with large dimensions and high thickness, and can meet the requirements of large frame structure castings in terms of precision, strength and surface quality.

[0061] In the description of this invention, it should be understood that if any term indicates an orientation or positional relationship, it is based on the orientation or positional relationship shown in the drawings, and does not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are for illustrative purposes only and should not be construed as limiting the invention.

[0062] The above embodiments are merely illustrative examples of the present invention and do not constitute a limitation on the scope of protection of the present invention. Any designs that are the same as or similar to the present invention are within the scope of protection of the present invention.

Claims

1. A flame cutting process for fabricating large frame castings based on thick continuous casting billets, characterized in that: Includes the following steps: S1. Pre-treat the surface of the thick continuous casting billet to make the surface of the thick continuous casting billet meet the required standards; S2. Select the cutting gas and adjust the selected gas to form a stable cutting flame; S3. Determine the optimal cutting path and cutting speed; Step S3 uses an intelligent algorithm to determine the optimal cutting path and cutting speed, wherein the cutting speed is 0.5-2 mm / s; S4. A stable cutting flame is used to cut the pretreated thick and wide continuous casting billet according to the optimal cutting path and cutting speed. The cutting of the pretreated thick and wide continuous casting billet includes a preheating stage and a cutting stage. The preheating stage involves heating the pretreated thick and wide continuous casting billet to the target temperature. The cutting stage involves cutting the heated thick and wide continuous casting billet until the cutting is completed. The target temperature range is 500-800℃. During the cutting process, a dynamic thermal monitoring device is also used to monitor the surface temperature and thermal gradient of the thick and wide continuous casting billet in real time, and combined with an adaptive algorithm, intelligently adjust the gas flow rate and cutting speed. S5. Cool the cut, thick, continuously cast billet; the cooling process is spray cooling. S6. Deburr and surface treatment are performed on the thick continuous casting billet after cooling. S7. Inspect the thick continuous casting billet after deburring and surface treatment. The thick continuous casting billet that passes the inspection is the finished casting.

2. The flame cutting process for fabricating large frame castings based on thick continuous casting billets as described in claim 1, characterized in that: The selected gas is a mixture of oxygen and a combustible gas, wherein the combustible gas is acetylene or propane.

3. The flame cutting process for fabricating large frame castings based on thick continuous casting billets as described in claim 2, characterized in that: The volume ratio of acetylene to oxygen is 1:1.1-1.3, and the volume ratio of propyne to oxygen is 1:1.2-1.

4.

4. The flame cutting process for fabricating large frame castings based on thick continuous casting billets as described in claim 1, characterized in that: The intelligent algorithms include ant colony optimization, genetic algorithm, and particle swarm optimization algorithm.

5. The flame cutting process for fabricating large frame castings based on thick continuous casting billets as described in claim 1, characterized in that: During the cutting process in step S4, a real-time feedback flame focus adjustment device is used to monitor and adjust the flame focus.

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