Processing method of low-loss high-temperature alloy master alloy bar material surface

Abstract

The invention relates to the technical field of alloy surface machining, in particular to a low-loss high-temperature alloy mother alloy bar surface machining method which comprises the following steps: S1, sand blasting treatment: carrying out sand blasting treatment on the bar surface by using a sand blasting machine; and S2, finish turning machining, wherein a lathe is used for directly conducting finish turning machining on the surface of the bar. Compared with traditional turning machining, the rough turning step is replaced with sand blasting treatment, machining loss and labor hour consumption are greatly reduced, and the product delivery rate is increased.

Description

Technical Field

[0001] The invention relates to the technical field of alloy surface processing, in particular to a low-loss high-temperature alloy master alloy bar surface processing method. Background Art

[0002] High-temperature alloys have become the preferred material for hot-end components of modern aircraft engines and gas turbines because of their excellent comprehensive properties such as high-temperature creep resistance, fatigue resistance, oxidation resistance and heat corrosion resistance. They are composed of a large amount of strategic or rare resource metal elements such as Ni, Co, W, Cr, Ta, Mo, Ta, Ti, Hf, Zr, Re, Ru, Ce, Y, La, etc., and are a costly key metal material.

[0003] The mainstream preparation method of high-temperature alloys is the melting and casting method. During the casting process, surface defects such as oxidation contamination layer, sand holes, and surface inclusions will be formed on the surface of the high-temperature alloy. Since the high-temperature alloy master alloy needs to be remelted in the downstream process, the master alloy bar needs to be surface treated to reduce the risk of these surface defects entering the interior of the alloy parts. At present, there are five traditional surface treatment methods for alloy bars: lathe turning, grinding wheel / sand belt grinding, shot blasting, sand blasting, and laser cleaning.

[0004] Turning processing benefits from its highest processing surface cleanliness. The surface is smooth and free of pollutants both under the naked eye and under the electron microscope. However, it has disadvantages such as high loss, low success rate, and fast tool wear, which leads to high processing costs.

[0005] Compared with turning, grinding wheel / belt grinding can reduce processing losses to a certain extent and can effectively remove surface defects such as surface oxide layer and sand holes. It has been partially applied in the industry. However, the biggest problem with grinding wheel / belt grinding is that there are grinding wheel abrasives embedded in the alloy surface. A large number of surface aluminum oxide inclusions can be observed under a microscopic electron microscope. Some high-temperature alloy products with strict quality requirements cannot be used directly.

[0006] Shot blasting, sand blasting, and laser cleaning are relatively efficient surface processing methods. Their processing loss is much lower than turning and grinding, and their processing efficiency is higher, but their processed surface cleanliness is poor. Shot blasting uses projectiles to hit the metal surface at high speed to break and remove impurities and attachments on the workpiece surface. Its processing loss is much lower than turning and its processing efficiency is higher, but it cannot completely remove the surface oxide layer. At the same time, the projectiles and sand used in shot blasting will adhere to the alloy surface, causing the alloy surface composition to change, and the alloy grade cannot be identified by the direct reading spectrometer. Sand blasting is also called sandblasting. It relies on the impact and cutting action of high-speed droplet particles on the metal surface to cause the surface oxide scale to be vibrated and destroyed and eventually detached from the metal surface. Its processing loss is much lower than turning and its processing efficiency is higher, but the alloy surface treated with sand blasting is matte, the alloy surface adsorbs more gas, and there is a situation where gravel is embedded in the alloy surface. Laser cleaning uses pulsed laser heating to form a rapidly expanding plasma on the metal surface and generate shock waves, which can break up the contaminated layer and peel it off, but it will cause secondary remelting on the alloy surface. The surface oxidation after laser cleaning is extremely serious under the electron microscope. Therefore, shot blasting, sand blasting, and laser cleaning are only used on parts to a certain extent, and are rarely used on high-temperature alloy master alloys.

[0007] In summary, developing a surface processing method that can take into account both low processing loss and high surface quality is of great significance to improving product delivery rate and reducing costs and increasing efficiency of enterprises. Summary of the invention

[0008] The present invention provides a low-loss high-temperature alloy master alloy bar surface processing method, which innovatively replaces the rough turning step in the traditional turning process with sand blasting treatment, combines the sand blasting treatment with the fine turning step, and provides a cost-reducing and efficiency-enhancing "sand blasting + fine turning" surface processing route, which specifically includes the following steps:

[0009] S1. Sand blasting: Use a sand blasting machine to blast the surface of the rod;

[0010] S2. Finishing machining: Use a lathe to perform finishing machining directly on the surface of the bar.

[0011] In some embodiments, the abrasive used in the sand blasting treatment in S1 includes at least one of steel sand, corundum sand, mullite sand, calcite sand, zircon sand, quartz sand, corundum, and glass sand.

[0012] Furthermore, the abrasive concentration of the sandblasting treatment is in the range of 0.18 to 2.7 g / m 3 .

[0013] Furthermore, the particle size of the abrasive in the sandblasting treatment is 68-178 μm (80-220 mesh).

[0014] Furthermore, the angle range of the sand blasting treatment is 40-80°.

[0015] Furthermore, the sand blasting time of the sand blasting process is 2-5 min / rod.

[0016] Furthermore, the pressure of the sand blasting treatment is 0.1-1.0 MPa.

[0017] Furthermore, the types of the sand blasting treatment include dry sand blasting or wet sand blasting.

[0018] In some embodiments, the finishing feed amount in S2 is 0.05-0.5 mm.

[0019] Furthermore, the finishing speed is 200-400r / min.

[0020] Furthermore, the finishing feed rate is 200-400r / min.

[0021] In some embodiments, the processing method further includes a pre-processing before S1, and the pre-processing includes cutting the bar.

[0022] In some embodiments, the processing method further includes post-processing after S2, and the post-processing includes grinding and / or cleaning.

[0023] Furthermore, the grinding process includes identifying and marking the local residual defects on the surface of the bar material, and locally grinding the defects with a handheld or automatic grinder.

[0024] Furthermore, the identification may be carried out manually or automatically.

[0025] Furthermore, the cleaning process includes cleaning dirt, oil and other stains on the surface of the rod.

[0026] Furthermore, the cleaning treatment method includes at least one of high-pressure air / water flushing, alcohol wiping, ultrasonic cleaning and laser cleaning.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) Compared with traditional turning, the present invention replaces the rough turning step with sand blasting, which greatly reduces processing loss and labor time consumption and improves the product delivery rate.

[0029] (2) Compared with grinding wheel / belt grinding, shot blasting, sand blasting, and laser cleaning, the surface cleanliness of the processing of the present invention is better. The subsequent finishing step effectively removes the contamination of the alloy bar surface caused by the sand blasting. The final alloy surface quality is as clean as that of the traditional turning processing, and the purity level evaluated by the HB 5406-2016 slag test is high.

[0030] (3) The present invention takes into account the advantages of both low processing loss and high surface quality, and is a surface processing method for high-temperature alloy master alloy bars that reduces costs and increases efficiency.

[0031] (4) Compared with the prior art, the present invention can reduce processing losses and lower processing costs while ensuring good surface quality and high cleanliness of the alloy obtained by processing by limiting multiple parameters of the two steps of sand blasting and fine turning, such as the pressure of sand blasting and the feed amount of fine turning. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. Among them:

[0033] Figure 1 This is a macroscopic image of the surface of the alloy bar after surface processing in Example 1;

[0034] Figure 2 , 3 4 is a microscopic electron microscope image of the surface of the alloy bar after surface processing in Example 1;

[0035] Figure 5 This is a macroscopic image of the surface of the alloy bar after surface processing in Comparative Example 1;

[0036] Figure 6 , 7 8 is a microscopic electron microscope image of the surface of the alloy bar after surface processing in Comparative Example 1;

[0037] Fig. 9 This is a macroscopic image of the surface of the alloy bar after surface processing in Comparative Example 2;

[0038] Fig.10 , 11 12 is a microscopic electron microscope image of the surface of the alloy bar after surface processing in Comparative Example 2;

[0039] Fig.13 This is a macroscopic image of the surface of the alloy bar after surface processing in Comparative Example 3;

[0040] Fig.14 , 1516 is a microscopic electron microscope image of the surface of the alloy bar after surface processing in Comparative Example 3;

[0041] Fig.17 This is a macroscopic image of the surface of the alloy bar after surface processing in Comparative Example 4;

[0042] Fig.18 , 19 20 is a microscopic electron microscope image of the surface of the alloy bar after surface processing in Comparative Example 4;

[0043] Fig.21 This is the liquid surface scum distribution diagram of Example 1;

[0044] Fig. 22 This is the liquid surface scum distribution diagram of Comparative Example 1;

[0045] Fig.23 This is the liquid surface scum distribution diagram of Comparative Example 2;

[0046] Fig.24 This is the liquid surface scum distribution diagram of Comparative Example 3;

[0047] Fig.25 This is the liquid surface scum distribution diagram of Comparative Example 4; DETAILED DESCRIPTION

[0048] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present invention. The process parameters of the following embodiments that do not specify specific conditions are usually based on conventional conditions.

[0049] According to a first aspect of the present invention, there is provided a surface processing method for a high temperature alloy master alloy bar, comprising the following steps:

[0050] S1. Sand blasting: Use a sand blasting machine to blast the surface of the rod;

[0051] S2. Finishing machining: Use a lathe to perform finishing machining directly on the surface of the bar.

[0052] Generally speaking, traditional turning processing is mainly divided into two steps: rough turning and fine turning: rough turning is a rough processing process, using a large-sized turning tool, the purpose of which is to remove the oxide contamination layer on the surface of the alloy, which can effectively reduce the wear of the oxide contamination layer on the fine turning tool during the fine turning process and avoid the occurrence of tool hitting, tool vibration and other phenomena. Since the surface of the cast alloy bar material often has undulations and is not a standard cylindrical shape, in order to remove all the oxide layers, a larger cutting depth (>1mm) must be used, and the cutting speed is correspondingly reduced, which is the bulk of the processing loss; while fine turning is a fine processing process, the purpose of which is to improve the surface quality of the alloy and make the alloy surface bright, only a small-sized turning tool is needed, the cutting depth is shallow (<0.5mm), and the processing speed is fast. The present invention innovatively replaces the rough turning step in the traditional turning process with sand blasting surface treatment, combines sand blasting with fine turning steps, and provides a low-loss "sand blasting + fine turning" surface processing route. On the one hand, the present invention removes most of the oxide layer on the surface of the alloy bar through sand blasting cleaning, reducing the damage of the oxide layer to the subsequent fine turning tool, not only replacing the role of the rough turning step, but also greatly reducing processing losses and labor time consumption; on the other hand, the present invention effectively removes the residual thin oxide film through the subsequent fine turning step, so that the surface cleanliness and brightness of the final alloy product are consistent with the traditional "rough turning + fine turning" turning process.

[0053] Therefore, the present invention innovatively replaces the rough turning step in the traditional turning process with sand blasting, combines the sand blasting with the fine turning step, and provides a "sand blasting + fine turning" surface processing route that reduces costs and increases efficiency. On the one hand, the present invention effectively removes the oxide layer on the surface of the alloy bar through sand blasting, avoiding damage to the subsequent fine turning tool by the oxide layer. While fully achieving the purpose of the rough turning step, it also greatly reduces the original huge processing loss and labor time consumption of this step in the traditional turning process; on the other hand, the present invention effectively removes the contamination of the alloy bar surface caused by sand blasting through the subsequent fine turning step, and also makes the surface cleanliness and brightness of the final alloy product consistent with the traditional "rough turning + fine turning" turning process.

[0054] The present invention performs rod cutting before sand blasting treatment, cuts off defective parts at the head and tail of the rod, fixes the rod with the head and tail cut off on a platform or a fixture frame for sand blasting surface treatment, mounts the sand blasted rod on a lathe, and performs fine processing on the alloy surface with a small feed amount, so that the alloy surface presents a metallic luster before entering the next process.

[0055] In the above-mentioned surface processing method, as a preferred implementation mode, in step S1, the abrasive for the sand blasting treatment in S1 includes at least one of steel sand, corundum sand, mullite sand, calcite sand, zircon sand, quartz sand, corundum, and glass sand. Iron sand and lead sand are too soft and easily adhere to the alloy surface to cause pollution, so they are not suitable for use.

[0056] The types of sandblasting treatment include dry sandblasting or wet sandblasting.

[0057] Too high abrasive concentration will cause the surface of the alloy ingot to overheat and cause serious surface damage, while too low abrasive concentration will lead to low processing efficiency. Preferably, the abrasive concentration of the sandblasting treatment ranges from 0.18 to 2.7 g / m 3 .

[0058] Too large abrasive particle size will lead to uneven surface treatment and easily cause mechanical damage to the surface, while too small abrasive particle size will reduce processing efficiency and fail to completely remove the contamination layer on the surface of the alloy ingot. Preferably, the particle size of the abrasive for sandblasting treatment is 68-178 μm (80-220 mesh).

[0059] If the angle between the sandblasting direction and the surface of the alloy ingot is too large, a large amount of abrasive will be embedded in the surface of the alloy ingot to form pollution, while if the sandblasting angle is too small, the processing efficiency will be reduced and the pollution layer on the surface of the alloy ingot cannot be completely removed. Preferably, the angle range of the sandblasting treatment is 40-80°.

[0060] Too short a sand blasting time cannot completely remove the contamination layer on the surface of the alloy ingot; while too long a sand blasting time will cause unnecessary waste of time; according to the conventional Φ50-100mm high-temperature alloy master alloy bar specifications, preferably, the cleaning time is 2-5min / bar.

[0061] Too high a sandblasting pressure will cause a large amount of abrasive to be embedded in the surface of the alloy ingot, causing contamination, and will also cause overheating and damage to the surface of the alloy ingot, while too low a sandblasting pressure will result in low processing efficiency and failure to completely remove the contamination layer on the surface of the alloy ingot. Preferably, the pressure of the sandblasting treatment is 0.1-1.0 MPa.

[0062] In the above-mentioned surface processing method, as a preferred embodiment, in step S2, the finishing turning is a high-speed turning process. The high-temperature alloy master alloy bar material itself has high strength. Excessive feed rate will cause destructive damage to the turning tool head, resulting in frequent maintenance and replacement of the tool head. At the same time, since most of the oxide scale on the surface of the bar material has been effectively removed in step S1, the finishing turning feed rate does not need to be set too large. A small feed rate is used during the finishing process. Preferably, the small feed rate is 0.05 to 0.5 mm.

[0063] Since most of the oxide scale on the surface of the bar has been effectively removed in step S1, the finishing speed can be set higher to improve the processing efficiency. Preferably, the speed is 200-400r / min.

[0064] In order to obtain a better flatness of the master alloy bar, the finishing feed rate should be set to be smaller, but too small a feed rate will also reduce the processing efficiency. Preferably, the feed rate is 0.05-0.2 mm / r.

[0065] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. 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.

[0066] Example 1

[0067] This embodiment adopts the present invention to perform surface processing on a K418 alloy round bar with a diameter of 80 mm, and the specific operations are as follows:

[0068] (1) Before surface processing, the bar is cut to remove the defective parts at the head and tail of the bar.

[0069] (2) Sand blasting: Place the rod after cutting the head and tail on the platform and use a sand blasting machine to blast its surface. Use 150 mesh quartz sand abrasive for dry blasting. The abrasive concentration is 1.0g / m 3 The angle of the sand blasting treatment is about 60°, the sand blasting time is 2.5 min / rod, and the pressure of the sand blasting treatment is set to 0.6 MPa.

[0070] (3) Finishing machining: The sandblasted bar is mounted on a lathe and the bar surface is directly finished with a feed rate of 0.3 mm, a rotation speed of 200 r / min and a feed rate of 0.1 mm / r.

[0071] (4) After surface processing, visually inspect the surface of the bar, use a handheld grinder to grind away any residual defects, and finally wipe the surface of the bar with alcohol, weigh and record it, and package it for storage.

[0072] Comparative Example 1

[0073] Comparative Example 1 The K418 alloy round bars of the same batch as Example 1 were surface processed by conventional turning, and the specific operation was as follows:

[0074] (1) Before surface processing, the bar is cut to remove the defective parts at the head and tail of the bar.

[0075] (2) Rough turning: After cutting the head and tail, install the bar on the lathe, use a large-size turning tool to rough-machine the bar surface, set the feed amount to 1mm, the speed to 80r / min, and the feed rate to 0.5mm / r to remove most of the black skin on the surface.

[0076] (3) Finishing machining: After rough turning, replace the small-sized turning tool and use a feed amount of 0.3 mm, a rotation speed of 200 r / min and a feed rate of 0.1 mm / r to finish the surface of the bar.

[0077] (4) After surface processing, visually inspect the surface of the bar, use a handheld grinder to grind away any residual defects, and finally wipe the surface of the bar with alcohol, weigh and record it, and package it for storage.

[0078] Comparative Example 2

[0079] Comparative Example 2: The K418 alloy round bars of the same batch as Example 1 were surface processed by sand blasting. The specific operation is as follows:

[0080] (1) Before surface processing, the bar is cut to remove the defective parts at the head and tail of the bar.

[0081] (2) Sand blasting: Fix the rod after cutting the head and tail on the sand blasting table, and use 150 mesh quartz sand abrasive for dry sand blasting. The abrasive concentration is 1.0g / m 3 The angle of the sand blasting treatment is about 60°, the sand blasting time is 2.5 min / rod, and the pressure of the sand blasting treatment is set to 0.6 MPa.

[0082] (3) After surface processing, visually inspect the surface of the bar, use a handheld grinder to grind away any residual defects, and finally wipe the surface of the bar with alcohol, weigh and record it, and package it for storage.

[0083] Comparative Example 3

[0084] Comparative Example 3: The K418 alloy round bars of the same batch as Example 1 were surface processed by laser cleaning. The specific operation is as follows:

[0085] (1) Before surface processing, the bar is cut to remove the defective parts at the head and tail of the bar.

[0086] (2) Laser cleaning: Place the bar material after cutting on the ground and use a handheld laser to clean its surface. The cleaning mode is dry method, the light source type is set to Gaussian light, the pulse frequency is set to 3000kHz, and the laser power is set to 800W.

[0087] (3) After surface processing, visually inspect the surface of the bar, use a handheld grinder to grind away any residual defects, and finally wipe the surface of the bar with alcohol, weigh and record it, and package it for storage.

[0088] Comparative Example 4

[0089] Comparative Example 4: The K418 alloy round bars of the same batch as Example 1 were surface processed by shot blasting. The specific operation is as follows:

[0090] (1) Before surface processing, the bar is cut to remove the defective parts at the head and tail of the bar.

[0091] (2) Shot blasting: Place the cut rods into a drum shot blasting machine for shot blasting. Use No. 45 steel shot as the shot. The rod loading capacity for each shot blasting is 250 kg. The shot blasting time is 30 min. The shot blasting amount is 160 kg / min. The shot blasting speed is 60 m / s.

[0092] (3) After surface processing, visually inspect the surface of the bar, use a handheld grinder to grind away any residual defects, and finally wipe the surface of the bar with alcohol, weigh and record it, and package it for storage.

[0093] The surface cleanliness of the rods after surface processing in Example 1 and Comparative Examples 1-4, the purity grade evaluated by the scum test according to HB 5406-2016, the statistical processing loss, and the working time consumption are compared respectively. The specific data are shown in Table 1 and Table 2.

[0094] Table 1 (Surface cleanliness)

[0095] sample Physical ingot surface Microscopic electron microscope surface Example 1 Macro surface finish (see Figure 1 ) No impurities on the microscopic surface (see Figure 2 , 3 、4) Comparative Example 1 Macro surface finish (see Figure 5 ) No impurities on the microscopic surface (see Figure 6 , 7 、8) Comparative Example 2 Macro surface matte (see Fig. 9 ) Microscopic surface embedded in quartz sand (see Fig.10 , 11 、12) Comparative Example 3 Macroscopic surface brightness (see Fig.13 ) Remelting and secondary oxidation phenomenon occurs on the microscopic surface (see Fig.14 , 15 、16) Comparative Example 4 Macroscopic surface brightness (see Fig.17 ) Iron-containing impurities attached to the microscopic surface (see Fig.18 , 19 、20)

[0096] Table 2 (Purity level, statistical processing loss, and working hours)

[0097] sample Liquid surface scum distribution Purity level Processing loss Working hours consumption Example 1 (See Fig.21 ) Level 0 22kg / ton 5 units per hour / ton Comparative Example 1 (See Fig. 22 ) Level 0 65kg / ton 8 units per hour / ton Comparative Example 2 (See Fig.23 ) Level 2 4kg / ton 1 unit per hour / ton Comparative Example 3 (See Fig.24 ) Level 3 5kg / ton 4 units per hour / ton Comparative Example 4 (See Fig.25 ) Level 2 5kg / ton 1 unit per hour / ton

[0098] It can be seen from the data in Table 1 and Table 2 that, compared with Comparative Example 1 of the conventional turning process, Example 1 of the present invention reduces 66% of processing loss and 38% of man-hour consumption while ensuring that the surface cleanliness is not reduced, thereby improving economic benefits. Compared with other surface treatment methods such as sandblasting, shot blasting, and laser cleaning, Example 1 of the present invention has significantly better surface cleanliness, and has significantly less scum after inspection according to HB 5406-2016, and has a higher purity level.

[0099] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A low-loss high-temperature alloy master alloy bar surface processing method, characterized in that: The steps include: S1. Sand blasting: Use a sand blasting machine to blast the surface of the rod; S2. Finishing machining: Use a lathe to perform finishing machining directly on the surface of the bar.

2. The processing method according to claim 1, characterized in that: The abrasive used in the sand blasting treatment in S1 includes at least one of steel sand, corundum sand, mullite sand, calcite sand, zircon sand, quartz sand, corundum sand, and glass sand.

3. The processing method according to claim 1, characterized in that: The abrasive concentration range in S1 is 0.18 to 2.7 g / m 3 , and / or, the particle size of the abrasive is 68-178 μm.

4. The processing method according to claim 1, characterized in that: The angle range of the sand blasting treatment in S1 is 40-80°, and / or the sand blasting time of the sand blasting treatment is 2-5 min / rod, and / or the pressure of the sand blasting treatment is 0.1-1.0 MPa, and / or the type of the sand blasting treatment includes dry sand blasting or wet sand blasting.

5. The processing method according to claim 1, characterized in that: The feed amount described in S2 is 0.05-0.5 mm.

6. The processing method according to claim 1, characterized in that: The finishing turning speed in S2 is 200-400 r / min, and / or the finishing turning feed rate is 200-400 r / min.

7. The processing method according to claim 1, characterized in that: The processing method further includes a pre-processing before S1, wherein the pre-processing includes cutting the bar material, and / or the processing method further includes a post-processing after S2, wherein the post-processing includes grinding and / or cleaning.

8. The processing method according to claim 7, characterized in that: The grinding process includes identifying and marking the local residual defects on the surface of the bar material, and locally grinding the defective parts with a handheld or automatic grinder.

9. The processing method according to claim 8, characterized in that: The identification is carried out by manual identification or automatic machine identification.

10. The processing method according to claim 9, characterized in that: The cleaning method includes at least one of high-pressure air / water flushing, alcohol wiping, ultrasonic cleaning and laser cleaning.

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