Manufacturing process of friction disc and control disc of vacuum filter

Abstract

The invention relates to the technical field of metal part casting, in particular to a manufacturing process of a friction disc and a control disc of a vacuum filter. Preparing the following metal materials in percentage by weight: 4%-6% of Z16 pig iron, 8%-10% of carbon steel, 6%-8% of 75 ferrosilicon, 2%-4% of carbon ferromanganese, 0.8%-1.5% of ferrophosphorus, 0.5%-1% of ferroboron, 20%-25% of metal furnace charge and 20%-25% of iron alloy; a 2t / h furnace pipe hot air acid cupola furnace is adopted as smelting equipment, firstly, Z16 pig iron, carbon steel, carbon ferromanganese, ferrophosphorus, metal furnace charge and iron alloy are smelted, and the tapping temperature of molten iron is larger than 1420 DEG C; 75 ferrosilicon is crushed to be 2-8 mm thick, inoculation treatment is carried out, ferroboron is crushed to be 2-8 mm thick, the ferroboron is baked to be dark red, and after tapping, the ferroboron is placed in a ladle. Molten iron with the temperature of 1320-1340 DEG C is poured into an iron tapping groove, inoculated silicon iron is poured into the iron tapping groove, the molten iron with the temperature of 1320-1340 DEG C is mixed with the inoculated silicon iron, and then the molten iron with the temperature of 1320-1340 DEG C is poured into a ladle to be mixed with ferroboron.

Description

Technical Field

[0001] The invention relates to the technical field of metal parts casting, in particular to a manufacturing process of a friction disc and a control disc of a vacuum filter. Background Art

[0002] The friction disc and control disc are the main parts of the disc vacuum filter, and are also the castings with the greatest technical difficulty in manufacturing. The friction disc and control disc are a pair of friction pairs working under lubricated conditions. They not only require less wear during work, but also have a smaller friction coefficient to reduce power consumption. Wear under lubricated conditions is the most common and important form of wear, and it is also a more complex wear process. Because there is a lubricant between the friction surfaces, it can isolate the friction surfaces, bear pressure, reduce friction coefficients and reduce wear to a certain extent; therefore, the nature and existence of the lubricant have a direct relationship with other wear, but due to the influence of factors such as different specific pressures on the friction surface and processing accuracy, it is impossible to be completely in a liquid friction state. Therefore, the matrix structure of this material is required to be a multiphase structure, including a flexible base in which hard components are firmly embedded. Summary of the invention

[0003] To achieve the above object, the present invention provides the following technical solutions:

[0004] A manufacturing process for a friction disc and a control disc of a vacuum filter. The control disc and the friction disc are made of the same material. The manufacturing steps of the friction disc and the control disc are as follows:

[0005] S1. Prepare the following metal materials: Z16 pig iron, carbon steel, 75 ferrosilicon, carbon ferromanganese, ferrophosphorus, ferroboron, metal charge, ferroalloy;

[0006] S2. The smelting equipment uses a 2t / h furnace core hot air acid cupola, first smelting Z16 pig iron, carbon steel, carbon ferromanganese, ferrophosphorus, metal charge and ferroalloy, and the temperature of the molten iron out of the furnace is greater than 1420℃;

[0007] S3. Crush 75% ferrosilicon into 2-8mm thick and carry out inoculation treatment. Crush ferroboron into 2-8mm thick and bake until dark red. After tapping, place in the ladle.

[0008] S4. Pour molten iron at 1320℃-1340℃ into the iron trough, pour the inoculant ferrosilicon into the iron trough, mix with the molten iron at 1320℃-1340℃, and then pour into the iron ladle to mix with the ferroboron.

[0009] S5. Pour the mixed molten iron at 1320℃-1340℃ and keep it warm for 20h. After cooling, the friction disc and control disc are formed.

[0010] Preferred: Metal materials by weight percentage: Z16 pig iron 4%-6%, carbon steel 8%-10%, 75 ferrosilicon 6%-8%, carbon ferromanganese 2%-4%, ferrophosphorus 0.8%-1.5%, ferroboron 0.5%-1%, metal charge 18%-20%, ferroalloy 50%-60%.

[0011] Preferably, the metal charge includes 1.8% ferroniobium, 2% ferrovanadium, 1.8% ferromolybdenum, 2.2% nickel plate, 2.5% ferrotitanium, 2.1% metal bismuth, 1.5% metal molybdenum, 1.2% metal tungsten, and 3.2% metal chromium.

[0012] Preferably: before adding the boron cast iron batch material, two batches of coke separators must be added to prevent the mixing of molten iron of different grades. The molten iron at the junction must be completely cleared. Two triangular test pieces are cast for each bag of boron cast iron molten iron for quality inspection. The width of the white mouth of the triangular test piece section is controlled at 2-4mm.

[0013] Preferred: sand casting is adopted, the molding sand is baking sand, the plane parting is adopted, the mold processing allowance is 10mm for the upper plane, 8mm for the lower plane, and 6mm for the side; the pouring system is semi-closed, the molten iron is injected into the casting from the inner circle tangent through 8 pressure cap openings, 10 pressure cap air outlets are arranged along the circumference of the upper plane, and the casting line shrinkage rate is 1.1%.

[0014] Preferably, the friction disc and the control disc are both annular, the control disc is divided into a driving control disc and a driven control disc, the two control discs have the same diameter as the friction disc, a plurality of fan-shaped holes are arranged on the two driving control discs, and a plurality of circular holes are arranged on the friction disc.

[0015] Compared with the prior art, the invention has the following beneficial effects:

[0016] It significantly improves the mechanical strength, wear resistance and cutting performance of the friction disc and the control disc; it improves the fluidity of molten iron during casting, which is beneficial to shrinkage compensation, reduces internal shrinkage of cast iron, and better exerts the wear resistance of boron. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the working wear of the parts of the present invention;

[0018] Figure 2 This is a schematic diagram of the method for adding ferroboron and inoculated ferrosilicon of the present invention;

[0019] Figure 3 This is a front view of the control panel of the present invention;

[0020] Figure 4 It is the front view of the friction disc of the present invention.

[0021] Notes on figure numbers: 1. boron-carbon compound and phosphorus eutectic complex; 2. pearlite; 3. second sliding surface; 4. first sliding surface; 5. inoculated ferrosilicon; 6. iron tapping trough; 7. molten iron; 8. molten iron ladle; 9. ferroboron; 10. control plate; 11. fan-shaped hole; 12. friction plate; 13. circular hole. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the invention to clearly and completely describe the technical solutions in the embodiments of the invention. Obviously, the described embodiments are only part of the embodiments of the invention, not all of the embodiments. Based on the embodiments in the invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the invention.

[0023] A manufacturing process for a friction disc and a control disc of a vacuum filter. The control disc and the friction disc are made of the same material. The manufacturing steps of the friction disc and the control disc are as follows:

[0024] Implementation Benefit 1:

[0025] S1. Add metal materials by weight percentage: Z16 pig iron 4%, carbon steel 9%, 75 ferrosilicon 8%, carbon ferromanganese 2%, ferrophosphorus 1.2%, ferroboron 0.7%, metal charge 18.3%, ferroalloy 56.8%;

[0026] S2. The smelting equipment uses a 2t / h furnace core hot air acid cupola, first smelting Z16 pig iron, carbon steel, carbon ferromanganese, ferrophosphorus, metal charge and ferroalloy, and the temperature of the molten iron out of the furnace is greater than 1420℃;

[0027] S3. Crush 75% ferrosilicon into 5±3mm thick and carry out inoculation treatment. Crush ferroboron into 5±3mm thick and bake until dark red. After tapping, place in the ladle.

[0028] S4. Pour molten iron at 1330℃±10℃ into the iron trough, pour the inoculant ferrosilicon into the iron trough, mix with the molten iron at 1330℃±10℃, then pour into the iron ladle and mix with the ferroboron.

[0029] S5. Pour the mixed molten iron at 1330℃±10℃ and keep it warm for 20h. After cooling, the friction disc and control disc are formed.

[0030] Embodiment 2:

[0031] S1. Add metal materials by weight percentage: Z16 pig iron 5%, carbon steel 10%, 75 ferrosilicon 6%, carbon ferromanganese 4%, ferrophosphorus 0.8%, ferroboron 1%, metal charge 18.3%, ferroalloy 54.9%;

[0032] S2. The smelting equipment uses a 2t / h furnace core hot air acid cupola, first smelting Z16 pig iron, carbon steel, carbon ferromanganese, ferrophosphorus, metal charge and ferroalloy, and the temperature of the molten iron out of the furnace is greater than 1420℃;

[0033] S3. Crush 75% ferrosilicon into 5±3mm thick and carry out inoculation treatment. Crush ferroboron into 5±3mm thick and bake until dark red. After tapping, place in the ladle.

[0034] S4. Pour molten iron at 1330℃±10℃ into the iron trough, pour the inoculant ferrosilicon into the iron trough, mix with the molten iron at 1330℃±10℃, then pour into the iron ladle and mix with the ferroboron.

[0035] S5. Pour the mixed molten iron at 1330℃±10℃ and keep it warm for 20h. After cooling, the friction disc and control disc are formed.

[0036] Embodiment three:

[0037] S1. Add metal materials by weight percentage: Z16 pig iron 6%, carbon steel 8%, 75 ferrosilicon 7%, carbon ferromanganese 4%, ferrophosphorus 1.5%, ferroboron 0.8%, metal charge 18.3%, ferroalloy 54.4%;

[0038] S2. The smelting equipment uses a 2t / h furnace core hot air acid cupola, first smelting Z16 pig iron, carbon steel, carbon ferromanganese, ferrophosphorus, metal charge and ferroalloy, and the temperature of the molten iron out of the furnace is greater than 1420℃;

[0039] S3. Crush 75% ferrosilicon into 5±3mm thick and carry out inoculation treatment. Crush ferroboron into 5±3mm thick and bake until dark red. After tapping, place in the ladle.

[0040] S4. Pour molten iron at 1330℃±10℃ into the iron trough, pour the inoculant ferrosilicon into the iron trough, mix with the molten iron at 1330℃±10℃, then pour into the iron ladle and mix with the ferroboron.

[0041] S5. Pour the mixed molten iron at 1330℃±10℃ and keep it warm for 20h. After cooling, the friction disc and control disc are formed.

[0042] Chemical analysis results: (%)

[0043] C: 3.25, Si: 1.93, Mn: 0.94, P: 0.435, S: 0.045, B: 0.043.

[0044] Metallographic analysis: Graphite is evenly distributed in a chrysanthemum shape, and the length of graphite is 5-10mm at ×100 times; the matrix structure is 90% pearlite; binary phosphorus eutectics are distributed discontinuously, with a quantity of about 8%; about 2% of boron-carbon compounds are dispersed on the grain boundaries of the eutectic.

[0045] The driving end distribution head control disc and the driven end distribution head control disc have the same dimensions as the friction disc, except that the through hole on the end face of the annular ring is changed from a round hole to a fan-shaped hole. The driving control disc and the driven control disc have several fan-shaped holes. All surfaces are fully processed, and the net weight of the parts is about 100kg. The material design of these three parts is wear-resistant cast iron-boron cast iron;

[0046] The flexible base forms grooves to protect the lubricant after friction, and the two hard protruding components serve as a supporting skeleton to bear the pressure. In terms of material design, the engineering and technical personnel of the design unit and the manufacturing unit consulted a large amount of information to select several materials, and repeatedly compared and demonstrated in terms of mechanical strength, wear resistance, cutting performance, manufacturing difficulty, cost, etc., and finally selected boron cast iron as the material for manufacturing this part.

[0047] Boron cast iron has high wear resistance. The reason is that during the wear process, the high-hardness boron-carbon compound (microhardness can reach about HV1100) in the form of hard particles bears the wear under pressure conditions and becomes the first sliding surface, while the matrix structure - pearlite has a large hardness difference with the boron-carbon compound, resulting in wear difference and becomes the second sliding surface (see Figure 1 ). The concave part after pearlite wear is often filled with lubricating oil to supplement the first sliding surface, so that the tendency of the oil film on the first sliding surface to be cut off is reduced, which not only reduces the wear itself, but also makes the matching material less prone to wear.

[0048] In order to give full play to the wear-resistant effect of boron in cast iron, we also add 0.25-0.45% phosphorus to boron cast iron in the design of chemical composition to form a certain amount of binary phosphorus eutectic instead of ternary phosphorus eutectic. Because ternary phosphorus eutectic is relatively brittle and easy to peel off, it cannot be firmly embedded in pearlite, and its appearance will reduce the wear resistance of castings. The hardness of binary phosphorus eutectic is also quite high, and its microhardness can reach about HV750. In the matrix structure, it forms hard particles together with boron carbon compounds, which are evenly dispersed and embedded in pearlite, thus giving full play to the wear-resistant effect of boron in parts.

[0049] After adding boron and phosphorus to cast iron, the matrix structure hardly changes and is still pearlite. Only a part of boron-carbon compounds or a composite of boron-carbon compounds and phosphorus eutectic appears in steadite, which improves the macroscopic hardness of the casting, but does not cause great difficulties in cutting performance. Time proves that this has brought great convenience to the manufacturing and production of friction discs and control discs. It not only solves the problems of fan-shaped hole cracks and processing motion that are inevitable in the process of quenching 45 steel or quenching after carburizing the surface of 20 steel, but also solves the expensive cost and extremely difficult processing required when manufacturing the parts with high chromium cast iron. At the same time, it also meets the basic requirement that the lubricating oil film is not cut off when the friction disc and the control disc are working under lubricated conditions, thereby effectively improving its service life.

[0050] Although embodiments of the invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the invention, and the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A manufacturing process for a friction disk and a control disk of a vacuum filter, characterized in that: The control disc and the friction disc are made of the same material. The manufacturing steps of the friction disc and the control disc are as follows: S1. Prepare the following metal materials: Z16 pig iron, carbon steel, 75 ferrosilicon, carbon ferromanganese, ferrophosphorus, ferroboron, metal charge, ferroalloy; S2. The smelting equipment uses a 2t / h furnace core hot air acid cupola, first smelting Z16 pig iron, carbon steel, carbon ferromanganese, ferrophosphorus, metal charge and ferroalloy, and the temperature of the molten iron out of the furnace is greater than 1420℃; S3. Crush 75% ferrosilicon into 2-8mm thick and carry out inoculation treatment. Crush ferroboron into 2-8mm thick and bake until dark red. After tapping, place in the ladle. S4. Pour molten iron at 1320℃-1340℃ into the iron trough, pour the inoculant ferrosilicon into the iron trough, mix with the molten iron at 1320℃-1340℃, and then pour into the iron ladle to mix with the ferroboron. S5. Pour the mixed molten iron at 1320℃-1340℃ and keep it warm for 20h. After cooling, the friction disc and control disc are formed.

2. A manufacturing process for a vacuum filter friction disk and a control disk according to claim 1, characterized in that: Metal materials by weight percentage: Z16 pig iron 4%-6%, carbon steel 8%-10%, 75 ferrosilicon 6%-8%, carbon ferromanganese 2%-4%, ferrophosphorus 0.8%-1.5%, ferroboron 0.5%-1%, metal charge 18%-20%, ferroalloy 50%-60%.

3. The manufacturing process of the friction disk and control disk of a vacuum filter according to claim 1, characterized in that: The metal charge includes 1.8% ferroniobium, 2% ferrovanadium, 1.8% ferromolybdenum, 2.2% nickel plate, 2.5% ferrotitanium, 2.1% metallic bismuth, 1.5% metallic molybdenum, 1.2% metallic tungsten, and 3.2% metallic chromium.

4. The manufacturing process of a vacuum filter friction disk and a control disk according to claim 1, characterized in that: Before adding the boron cast iron batch material, two batches of coke separators must be added to prevent the mixing of molten iron of different grades. The molten iron at the junction must be completely cleared out. Two triangular test pieces are cast for each bag of boron cast iron for quality inspection. The width of the white part of the triangular test piece is controlled at 2-4mm.

5. The manufacturing process of the friction disk and control disk of a vacuum filter according to claim 1, characterized in that: Sand casting is adopted, the molding sand is baking sand, the plane parting, the mold processing allowance is 10mm for the upper plane, 8mm for the lower plane, and 6mm for the side; the pouring system is semi-closed, the molten iron is injected into the casting from the inner circle tangent through 8 pressure cap openings, 10 pressure cap air outlets are set along the circumference of the upper plane, and the casting line shrinkage rate is 1.1%.

6. The manufacturing process of the friction disk and control disk of a vacuum filter according to claim 1, characterized in that: The friction disc and the control disc are both annular, and the control disc is divided into a driving control disc and a driven control disc. The two control discs have the same diameter as the friction disc. A plurality of fan-shaped holes are arranged on the two driving control discs, and a plurality of circular holes are arranged on the friction disc.

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