CN215845697U - Extrusion rod and extrusion system for compacting inner surface of powder metallurgy part - Google Patents
Extrusion rod and extrusion system for compacting inner surface of powder metallurgy part Download PDFInfo
- Publication number
- CN215845697U CN215845697U CN202120349050.6U CN202120349050U CN215845697U CN 215845697 U CN215845697 U CN 215845697U CN 202120349050 U CN202120349050 U CN 202120349050U CN 215845697 U CN215845697 U CN 215845697U
- Authority
- CN
- China
- Prior art keywords
- extrusion
- extruded
- rod
- rod body
- amount
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Powder Metallurgy (AREA)
Abstract
The utility model relates to an extrusion rod and an extrusion system for compacting the inner surface of a powder metallurgy part, wherein the extrusion rod for compacting the inner surface of the powder metallurgy part comprises a core rod, a core rod and a pressing piece, wherein the longitudinal section of the core rod is basically T-shaped, and the extrusion rod comprises a rod body which is vertically arranged and a connecting head which is arranged at the top of the rod body; the extrusion piece is annular, is sleeved on the periphery of the rod body and is positioned below the connector; the method is characterized in that: the extruded articles have two at least, and follow the length direction interval arrangement of the body of rod, adjacent two be provided with between the extruded article and be cyclic annular and overlap and establish the peripheral support ring of the body of rod, each the size of extruded article's outline is crescent from bottom to top. The extrusion rod can extrude the inner surface of the central hole of the subsequent part to be extruded in a discontinuous sliding manner, so that the density of the inner surface of the part to be extruded is improved, the surface pores are reduced, and the density of the inner surface of the central hole of the part to be extruded is improved.
Description
Technical Field
The utility model belongs to the field of powder metallurgy, and particularly relates to an extrusion rod and an extrusion system for compacting the inner surface of a powder metallurgy part.
Background
Powder metallurgy is the technical discipline of manufacturing metal powders and of manufacturing materials or articles starting from metal powders (including the incorporation of non-metal powders) in the basic process of shaping and sintering. In a broad sense, it also includes a technique of producing a material or a product by a form-sintering method using a powder of a non-metallic compound such as an oxide, a nitride, or a carbide as a raw material. The powder metallurgy process is a technological process of adding raw material powder into a certain die cavity, then pressing and forming, and sintering under a certain condition or sintering in a specific die to obtain a product. With the development of industry, powder metallurgy is a technology capable of manufacturing parts with complex shapes, can save raw materials, save energy and labor, and is suitable for mass production.
Powder metallurgy is an efficient process for producing parts of high strength and complex shape. Currently, powder metallurgy processes have been able to produce densities in excess of 7.4g/cm by using high performance powders, forming, sintering and special post-processing3The iron-based part of (1). The density of the product can be greatly improved by the re-pressing and re-sintering technology. The density of iron-based powder metallurgy parts can only reach 7.1g/cm by adopting common atomized iron powder through forming and sintering3Left and right. If the density of the powder metallurgy part is further improved, a pressing and re-sintering process of forming, pre-sintering, re-pressing and secondary sintering can be adopted, wherein the pre-sintering has two functions: firstly, annealing the powder which is processed and hardened during forming is carried out, so that the yield strength of iron powder particles is reduced, and the density is improved during secondary pressing; secondly, the organic lubricant in the product is removed, the organic lubricant occupies a large space in the product due to low density, the lubricant is difficult to compress during forming, the density is limited to be improved, more than 95% of the lubricant can be removed during pre-sintering, and the position occupied by the lubricant can be compressed during re-pressing, so that the density is favorably improved. For parts with complex shapes, an expensive CNC press is needed for forming, but re-pressing is difficult, and each step is difficult to compact or a compact part is difficult to select.
For powder metallurgy parts made of other materials, the powder metallurgy parts are produced by adopting the modes of powder making, mixing, sheathing, extruding (forging), machining and the like, the performance of the parts is better and even exceeds that of directly forged parts, but the flow of the parts is longer, the manufacturing cost is higher, the manufacturing of the parts is not a near-net forming process, and the advantages of the powder metallurgy process cannot be fully exerted.
As parts for electromechanical applications, the conventional methods are all formed by machining. The current main processing methods of the machined parts comprise that steel is directly formed by a machining method and formed by cold extrusion, wherein the machining method has the disadvantages of long working procedures, low utilization rate of raw materials which is about 40-60%, high product cost, poor consistency and low production efficiency, and the requirement on good consistency of large batches is difficult to meet.
The cold extrusion method is adopted for forming, and generally, warm forging is needed for preparing a blank, and then cold extrusion forming is needed. The forged piece has high dimensional precision, good dimensional consistency, smooth surface, high tooth profile precision of an internal gear, clear gear outline and less machining allowance of the outer surface; the material utilization rate reaches about 90 percent; due to large deformation, the service life of a warm forging die (female die) is 5000-6000, and the service life of a cold extrusion die (male die) is 8000-10000; the cold extrusion piece has smooth surface, less machining allowance, short production period and high production efficiency, and obviously reduces the subsequent machining workload. However, the cold extrusion method has large die loss and the cost is difficult to meet the requirements of industries such as automobiles, motorcycles and the like.
Therefore, it is necessary to develop a new manufacturing method to solve the problems of precision, density, strength, etc. of the powder metallurgy product.
SUMMERY OF THE UTILITY MODEL
The first technical problem to be solved by the utility model is to provide an extrusion rod for compacting the inner surface of a powder metallurgy part, which can uniformly extrude a subsequent part to be extruded, aiming at the current situation of the prior art.
A second technical problem to be solved by the present invention is to provide an extrusion system having the above extrusion bar, in view of the current state of the art.
A third technical problem to be solved by the present invention is to provide a method for manufacturing a powder metallurgy part having high density and high strength, in view of the current state of the prior art.
The technical scheme adopted by the utility model for solving the first technical problem is as follows: an extrusion rod for the internal surface of powder metallurgy part is composed of
The longitudinal section of the core rod is basically T-shaped, and the core rod comprises a rod body which is vertically arranged and a connector which is arranged at the top of the rod body;
the extrusion piece is annular, is sleeved on the periphery of the rod body and is positioned below the connector;
the method is characterized in that: the extruded articles have two at least, and follow the length direction interval arrangement of the body of rod, adjacent two be provided with between the extruded article and be cyclic annular and overlap and establish the peripheral support ring of the body of rod, each the size of extruded article's outline is crescent from bottom to top.
In order to realize the gradual diffusion of the subsequent part to be extruded, the gradient difference Δ L between the outer contour dimensions of two adjacent extrusion pieces is preferably 0.01% -8.0%, wherein Δ L is (L1-L2)/L1, L1 is the dimension of the outer contour of the extrusion piece positioned above, and L2 is the dimension of the outer contour of the extrusion piece positioned below. Therefore, the extrusions with different outline sizes are extruded in the center hole of the part to be extruded in a discontinuous sliding mode, so that the surface density of the part to be extruded is improved, the surface pores are reduced, and the inner surface density of the center hole of the part to be extruded is improved.
In order to prevent the support rings from interfering with the parts to be extruded, the projections of the support rings in the vertical direction fall within the extrusions.
In order to improve the extrusion capacity, 2-30 extrusion pieces are provided.
The support ring and the extrusion part are limited on the rod body, can adopt a welding fixing mode, can also adopt a bonding mode, and can also adopt a nut locking mode, but from the angle of facilitating the disassembly and the replacement of the extrusion part, preferably, a guide part is arranged below the extrusion part at the lowest position, the guide part is annular and is positioned outside the rod body, a nut used for locking the guide part, the support ring and the extrusion part on the rod body is arranged below the guide part, and the nut is positioned on the periphery of the rod body.
The technical scheme that utility model solved above-mentioned second technical problem and adopted does: an extrusion system with above-mentioned extrusion stick, characterized by: the extrusion die comprises a female die, wherein an opening for placing a part to be extruded with a central hole in the female die is formed in the center of the female die, a step for placing the part to be extruded is formed in the opening, each extrusion piece can penetrate through the central hole of the part to be extruded from top to bottom, and the size of the outer contour of each extrusion piece is larger than that of the inner contour of the central hole of the part to be extruded.
In order to prevent the part to be extruded from being elastically deformed too much during extrusion, the horizontal distance of the cross section of the size of the inner contour of the opening of the female die is D1, and the horizontal distance of the cross section of the outer contour of the part to be extruded is D2, wherein D1 is (1.001-1.200) D2.
The technical scheme that utility model solved above-mentioned third technical problem and adopted does: the manufacturing method for preparing the powder metallurgy part by using the extrusion system is characterized by at least comprising the following steps of:
1) designing the components of the material: mixing carbon, iron, chromium, molybdenum, copper and nickel into mixed powder according to the following mass percent, wherein the mixed powder comprises the following components in percentage by mass: carbon: 0-1.5%, copper: 0-4%, nickel: 0-5%, molybdenum: 0-2%, chromium: 0-6%, not more than 2% of unavoidable impurities, 0.1-1% of a lubricant, iron: the balance; wherein, chromium, molybdenum, copper and nickel are added in the form of iron alloy or master alloy, carbon is added in the form of graphite, and then a lubricant with the mass percent content of 0.1-1% is added;
2) pressing: pressing the mixed powder obtained in the step 1) on a press to obtain the mixed powder with the density of 6.4-7.4 g/cm3The green body of the part is pressed at a pressure of more than 400 MPa;
3) and (3) sintering: sintering the part green body obtained in the step 2) at the temperature of 1000-1350 ℃, wherein the sintering time is 5-180 min;
4) extruding: placing a part to be extruded in the extrusion system for extrusion;
5) and (3) heat treatment: and carrying out heat treatment on the extruded part.
Preferably, annealing treatment can be carried out on the part with the carbon content higher than 0.2% or the total content of molybdenum, chromium and nickel alloy higher than 2% between the step 3) and the step 4), the annealing temperature is 750-1080 ℃, the annealing heat preservation time is 5-200 min, and the cooling speed from the annealing temperature to 300 ℃ after annealing is less than 1.5 ℃/S. The annealing process can reduce the hardness, homogenize the structure, eliminate or reduce the internal stress, obtain better material toughness and enable the material to be extruded more easily.
Preferably, in step 4), the total extrusion deformation design amount Δ d ═ d (d)max-d0)/d0The total extrusion deformation design quantity delta d is controlled within 10 percent. An excessive total extrusion deformation may subject the die to an excessive compressive stress to be easily damaged or greatly reduce the life of the die.
Preferably, in the step 5), the quenching temperature is 750-1250 ℃, the quenching heat preservation time is 30-45 min, the tempering temperature is 150-600 ℃, and the tempering heat preservation time is 5-200 min. Quenching can improve the structure, strength, hardness and wear resistance; tempering can eliminate or reduce quenching stress, improve brittleness after quenching, and make the size and performance of the part more stable.
Compared with the prior art, the utility model has the advantages that: the extrusion rod can extrude the inner surface of the central hole of the subsequent part to be extruded in a discontinuous sliding manner, so that the density of the inner surface of the part to be extruded is improved, the surface pores are reduced, and the density of the inner surface of the central hole of the part to be extruded is improved; in the extrusion process, due to the movement of the extrusion rod, the material flows, and the density of partial area of the powder metallurgy part is improved; in addition, due to the adoption of the powder metallurgy process for forming, the shape of the part to be extruded is closer to the shape of a final product, so that the extrusion allowance is small, and the service life of the die is longer. Meanwhile, due to the improvement of the density, the performance of the part is greatly improved compared with that of a common powder metallurgy part, and the application field of powder metallurgy is expanded.
Drawings
FIG. 1 is a schematic structural diagram of a part to be extruded according to the present embodiment;
FIG. 2 is a front view of a part to be extruded;
FIG. 3 is a cross-sectional view of an extrusion system;
FIG. 4 is a schematic structural view of the extrusion of FIG. 3;
FIG. 5 is a cross-sectional view of a female die with a part placed therein to be extruded;
FIG. 6 is a cross-sectional view of a female die with a part to be extruded placed therein;
FIG. 7 is a schematic structural view of a female mold in the present embodiment;
FIG. 8 is a schematic view of the profile of the extruded part and extrusion after uniform extrusion;
FIG. 9 is a schematic view of the profile of an extrusion and part to be extruded after non-uniform extrusion with only partial extrusion;
FIG. 10 is a profile before the central hole of the part to be extruded is extruded;
FIG. 11 is a diagram showing the feature of a part to be extruded after the central hole is extruded;
FIG. 12 is a scanned view of the inner surface of the central bore of the heat treated part of FIG. 11.
Detailed Description
The utility model is described in further detail below with reference to the accompanying examples.
Example 1:
as shown in fig. 1 to 12, a first preferred embodiment of the present invention is shown.
As shown in fig. 3, the extrusion system of the present embodiment includes a female die 2 and an extrusion rod 1 for densifying the inner surface of the powder metallurgy part, an opening 21 for placing therein the part to be extruded 3 having a central hole 31 is opened at the center of the female die 2, a step 211 for placing the part to be extruded 3 is formed in the opening 21, and as shown in fig. 7, the longitudinal section of the opening 21 of the female die 2 is T-shaped. As shown in fig. 1, the part 3 to be extruded has a central hole 31 in the center.
As shown in fig. 3, the extrusion rod 1 of the present embodiment includes a core rod 11, an extrusion member 12, a support ring 13, a guide 14, and a nut 15. The core rod 11 is vertically arranged, and the longitudinal section of the core rod 11 is substantially T-shaped, and the core rod 1 includes a rod body 111 vertically arranged and a connector 112 arranged on the top of the rod body 111. The extrusion member 12 is ring-shaped and is disposed around the rod 111 and under the connector 112, and the central opening 121 of the extrusion member 12 is a non-circular hole, so that the extrusion member 12 only moves up and down relative to the core rod 11. In this embodiment, there are 3 or four extrusion pieces 12, and the extrusion pieces are arranged at intervals along the length direction of the rod body 111, a ring-shaped support ring 13 is arranged between two adjacent extrusion pieces 12 and is sleeved on the periphery of the rod body 111, and the projection of the support ring 13 along the vertical direction falls in each extrusion piece 12. The size of the outer contour of each extrusion piece 12 is gradually increased from bottom to top, and the size of the outer contour of each extrusion piece 12 is larger than the size of the inner contour of the central hole 31 of the part 3 to be extruded, specifically, the gradient difference Δ L between the sizes of the outer contours of two adjacent extrusion pieces 12 is 0.01% -8.0%, wherein Δ L is (L1-L2)/L1, L1 is the size of the outer contour of the extrusion piece 12 positioned above, and L2 is the size of the outer contour of the extrusion piece 12 positioned below. In addition, the guide 14 is located below the lowest extrusion 12 and is annular and is sleeved on the periphery of the rod body 111, the nut 15 is located below the guide 14, and the nut 15 is connected to the periphery of the rod body 111 and locks the guide 14, the support ring 13 and the extrusion 12 on the rod body 111.
As shown in fig. 3, the part 3 to be extruded is placed on the step 211 and located in the opening 21, the nut 15 is located in the central hole 31 of the part 3 to be extruded, when the part 3 to be extruded is extruded, the guide 14 and each extrusion piece 12 gradually penetrate through the central hole 31 of the part 3 to be extruded from top to bottom, the extrusion pieces 12 with different outer contour sizes are sequentially and discontinuously extruded in a sliding manner on the inner surface of the central hole 31 of the part to be extruded, and after uniform extrusion, as shown in fig. 8, the surface density of the part to be extruded is improved, the surface pores are reduced, and the inner surface density of the central hole 31 of the part to be extruded is improved.
The manufacturing method for preparing the powder metallurgy part by using the extrusion system comprises the following steps in sequence:
1) designing the components of the material: sintered steel, such as mixed powder of iron-chromium-molybdenum pre-alloy powder and carbon-copper, is adopted, and the components of the sintered steel are calculated according to the mass percentage: the atomized iron powder is 96.8%; 0.70% of carbon and 2% of copper powder, and then adding 0.5% of lubricant;
2) pressing: pressing the mixed powder obtained in the step 1) on a press under the pressing pressure of 600MPa to obtain the mixed powder with the pressing density of 7.1g/cm3The green part of (1);
3) and (3) sintering: sintering the green part in the step 2) at the temperature of 1200 ℃, wherein the sintering time is 20 min;
4) annealing: the annealing temperature is 850 ℃, nitrogen is adopted as the atmosphere, the annealing heat preservation time is 60min, and the cooling speed from the annealing temperature to 300 ℃ after annealing is 0.1 ℃/S.
5) Extruding: placing the annealed part 3 to be extruded in an extrusion system for extrusion; three extrusion pieces 12 are arranged in the extrusion system, so that three-gear extrusion pieces are adopted for extrusion, the total extrusion deformation design amount delta d is (dmax-d0)/d0, the total extrusion deformation design amount delta d is 5%, the first gear extrusion amount is 1%, the second gear extrusion amount is 1.5%, and the third gear extrusion amount is 2.5%, wherein the first gear extrusion amount is the extrusion amount of the extrusion piece 12 positioned at the lowermost part after extrusion, the second gear extrusion amount is the extrusion amount of the extrusion piece 12 positioned at the middle part after extrusion, and the third gear extrusion amount is the extrusion amount of the extrusion piece 12 positioned at the uppermost part after extrusion; referring specifically to fig. 8, the extrusion amount is relatively uniform, i.e., the distance between the outer profile of the extrusion member and the central hole of the part 3 to be extruded is equal everywhere in the circumferential direction. The compactness is higher compared to the non-uniform amount of extrusion in fig. 9, see in particular fig. 11. The outer contour dimension in the above embodiment, that is, when the outer contour of the extrusion is circular, is the outer diameter.
6) And (3) heat treatment: and (3) carrying out heat treatment on the extruded part, wherein the quenching temperature is 850 ℃, the quenching heat preservation time is 30min, the carbon potential is 0.7%, the tempering temperature is 200 ℃, the tempering heat preservation time is 120min, the appearance of the inner surface of the central hole of the part is shown in figure 12, and the metallographic structure of the inner hole surface compact layer is changed after the heat treatment, the original pearlite is converted into martensite, and the surface hardness, the strength and the wear resistance of the part are improved.
Example 2:
this embodiment differs from embodiment 1 described above only in that: the extrusion amount of each gear in the step 5) is different, specifically, the total extrusion deformation design amount Δ d is 5%, the first gear extrusion amount is 2.5%, the second gear extrusion amount is 1.5%, and the third gear extrusion amount is 1%, wherein the first gear extrusion amount is the extrusion amount of the extrusion piece 12 located at the lowermost position after extrusion, the second gear extrusion amount is the extrusion amount of the extrusion piece 12 located at the middle position after extrusion, and the third gear extrusion amount is the extrusion amount of the extrusion piece 12 located at the uppermost position after extrusion.
Example 3:
this embodiment differs from embodiment 1 described above in that: the preparation method has different component designs and parameter selections, and specifically comprises the following steps:
the manufacturing method for preparing the powder metallurgy part by using the extrusion system comprises the following steps in sequence:
1) designing the components of the material: sintered steel, such as mixed powder of iron-chromium-molybdenum pre-alloy powder and carbon-copper, is adopted, and the components of the sintered steel are calculated according to the mass percentage: the atomized iron powder is 95.6 percent; 0.80% of carbon and 3% of copper powder, and then adding 0.6% of lubricant;
2) pressing: pressing the mixed powder obtained in the step 1) on a press under the pressing pressure of 550MPa to obtain the mixed powder with the pressing density of 7.0g/cm3The green part of (1);
3) and (3) sintering: sintering the green part in the step 2) at the temperature of 1300 ℃ for 30 min;
4) extruding: placing the sintered part 3 to be extruded in an extrusion system for extrusion; four extrusion pieces 12 in the extrusion system are adopted, so that four-gear extrusion pieces are adopted for extrusion, the total extrusion deformation design amount delta d is (dmax-d0)/d0, the total extrusion deformation design amount delta d is 7%, the first gear extrusion amount is 2.5%, the second gear extrusion amount is 2.0%, the third gear extrusion amount is 1.5%, the fourth gear extrusion amount is 1.0%, and the first gear extrusion amount, the second gear extrusion amount, the third gear extrusion amount and the fourth gear extrusion amount are respectively corresponding extrusion amounts of the extrusion pieces from bottom to top after extrusion;
5) and (3) heat treatment: and carrying out heat treatment on the extruded part, wherein the quenching temperature is 850 ℃, the quenching heat preservation time is 30min, the carbon potential is 0.7%, the tempering temperature is 200 ℃, and the tempering heat preservation time is 120 min.
Example 4:
this embodiment differs from embodiment 1 described above in that: differences exist in the sintering parameters in step 3), specifically: sintering the green part at 1280 ℃ for 50 min; the extrusion amount of each gear in the step 4) is different, specifically: the total extrusion deformation design amount delta d is (dmax-d0)/d0, the total extrusion deformation design amount delta d is 7%, the first-gear extrusion amount is 2.5%, the second-gear extrusion amount is 2.0%, the third-gear extrusion amount is 2.0%, the fourth-gear extrusion amount is 1.5%, and the first-gear extrusion amount, the second-gear extrusion amount, the third-gear extrusion amount and the fourth-gear extrusion amount are respectively corresponding extrusion amounts after extrusion is carried out on an extrusion piece from bottom to top; the horizontal distance of the cross section of the inner contour of the opening 21 of the female die 2 is D1 and the horizontal distance of the cross section of the outer contour of the part 3 to be extruded is D2, wherein D1 is 1.01D2, see in particular fig. 7 and the drawings.
Example 5:
1) designing the components of the material: sintered steel is adopted, and the components of the sintered steel are as follows by mass percent: the atomized iron powder is 83.9%; 4% of copper powder, 5% of nickel powder, 1% of molybdenum powder and 6% of chromium powder, and then adding 0.1% of lubricant;
2) pressing: pressing the mixed powder obtained in the step 1) on a press under the pressing pressure of 600MPa to obtain the mixed powder with the pressing density of 6.4g/cm3The green part of (1);
3) and (3) sintering: sintering the green part in the step 2) at the temperature of 1000 ℃ for 5 min;
4) annealing: the annealing temperature is 1080 ℃, the atmosphere adopts nitrogen, the annealing heat preservation time is 5min, and the cooling speed from the annealing temperature to 300 ℃ after annealing is 0.1 ℃/S.
5) Extruding: placing the annealed part 3 to be extruded in an extrusion system for extrusion; three extrusion pieces 12 are arranged in the extrusion system, so that three-gear extrusion pieces are adopted for extrusion, the total extrusion deformation design amount delta d is (dmax-d0)/d0, the total extrusion deformation design amount delta d is 5%, the first gear extrusion amount is 1%, the second gear extrusion amount is 1.5%, and the third gear extrusion amount is 2.5%, wherein the first gear extrusion amount is the extrusion amount of the extrusion piece 12 positioned at the lowermost part after extrusion, the second gear extrusion amount is the extrusion amount of the extrusion piece 12 positioned at the middle part after extrusion, and the third gear extrusion amount is the extrusion amount of the extrusion piece 12 positioned at the uppermost part after extrusion; referring specifically to fig. 5, the extrusion amount is relatively uniform, i.e., the distance between the outer profile of the extrusion member and the central hole of the part 3 to be extruded is equal everywhere in the circumferential direction. The compactness is higher compared to the non-uniform amount of extrusion in fig. 7.
6) And (3) heat treatment: and carrying out heat treatment on the extruded part, wherein the quenching temperature is 1250 ℃, the quenching heat preservation time is 40min, the carbon potential is 0.7%, the tempering temperature is 150 ℃, and the tempering heat preservation time is 5 min. The horizontal distance of the cross section of the dimensions of the inner contour of the opening 21 of the female die 2 is D1 and the horizontal distance of the cross section of the central bore 31 of the part 3 to be pressed is D2, where D1 is 1.001D 2.
Example 6:
1) designing the components of the material: sintered steel is adopted, and the components of the sintered steel are as follows by mass percent: the atomized iron powder is 92.5 percent; 1.5 percent of carbon powder, 2 percent of nickel powder, 2 percent of molybdenum powder and 1 percent of chromium powder, and then adding a lubricant with the content of 1 percent;
2) pressing: pressing the mixed powder obtained in the step 1) on a press under the pressing pressure of 600MPa to obtain the mixed powder with the pressing density of 7.4g/cm3The green part of (1);
3) and (3) sintering: sintering the green part in the step 2) at the temperature of 1350 ℃ for 180 min;
4) annealing: the annealing temperature is 750 ℃, the atmosphere adopts nitrogen, the annealing heat preservation time is 200min, and the cooling speed from the annealing temperature to 300 ℃ after annealing is 0.1 ℃/S.
5) Extruding: placing the annealed part 3 to be extruded in an extrusion system for extrusion; three extrusion pieces 12 are arranged in the extrusion system, so that three-gear extrusion pieces are adopted for extrusion, the total extrusion deformation design amount delta d is (dmax-d0)/d0, the total extrusion deformation design amount delta d is 5%, the first gear extrusion amount is 1%, the second gear extrusion amount is 1.5%, and the third gear extrusion amount is 2.5%, wherein the first gear extrusion amount is the extrusion amount of the extrusion piece 12 positioned at the lowermost part after extrusion, the second gear extrusion amount is the extrusion amount of the extrusion piece 12 positioned at the middle part after extrusion, and the third gear extrusion amount is the extrusion amount of the extrusion piece 12 positioned at the uppermost part after extrusion; referring specifically to fig. 5, the extrusion amount is relatively uniform, i.e., the distance between the outer profile of the extrusion member and the central hole of the part 3 to be extruded is equal everywhere in the circumferential direction. The compactness is higher compared to the non-uniform amount of extrusion in fig. 7.
6) And (3) heat treatment: and carrying out heat treatment on the extruded part, wherein the quenching temperature is 750 ℃, the quenching heat preservation time is 45min, the carbon potential is 0.7%, the tempering temperature is 600 ℃, and the tempering heat preservation time is 200 min. The horizontal distance of the cross section of the dimensions of the inner contour of the opening 21 of the female die 2 is D1 and the horizontal distance of the cross section of the central bore 31 of the part 3 to be pressed is D2, where D1 is 1.200D 2.
Claims (7)
1. An extrusion rod for the internal surface of powder metallurgy part is composed of
The longitudinal section of the core rod (11) is in a T shape, and the core rod comprises a rod body (111) which is vertically arranged and a connector (112) which is arranged at the top of the rod body (111);
the extrusion piece (12) is annular, is sleeved on the periphery of the rod body (111) and is positioned below the connector (112);
the method is characterized in that: the extruded article (12) have two at least, and follow the length direction interval arrangement of the body of rod (111), adjacent two be provided with between extruded article (12) and be the annular and cover establish body of rod (111) outlying support ring (13), each the size of the outline of extruded article (12) is crescent from bottom to top, each extruded article (12) homoenergetic top-down passes central hole (31) of treating extruded part (3), and the size of the outline of each extruded article (12) all is greater than the size of the interior outline of central hole (31) of treating extruded part (3).
2. The squeeze bar of claim 1, wherein: the gradient difference DeltaL between the outer contour dimensions of two adjacent extrusion pieces (12) is 0.01% -8.0%, wherein DeltaL is (L1-L2)/L1, L1 is the dimension of the outer contour of the extrusion piece (12) positioned above, and L2 is the dimension of the outer contour of the extrusion piece (12) positioned below.
3. The squeeze bar of claim 1, wherein: the projection of the support ring (13) in the vertical direction falls within each of the pressers (12).
4. The squeeze bar of claim 2, wherein: the number of the extrusion pieces (12) is 2-30.
5. The squeeze bar of claim 2, wherein: a guide part (14) is arranged below the extrusion part (12) positioned at the lowest part, the guide part (14) is annular and positioned outside the rod body (111), a nut used for locking the guide part (14), the support ring (13) and the extrusion part (12) on the rod body (111) is arranged below the guide part (14), and the nut (15) is positioned at the periphery of the rod body (111).
6. An extrusion system having an extrusion bar of any one of claims 1 to 5, wherein: the die comprises a female die (2), wherein an opening (21) for placing a part (3) to be extruded with a central hole (31) therein is formed in the center of the female die (2), and a step (211) for placing the part (3) to be extruded is formed in the opening (21).
7. The extrusion press system of claim 6, wherein: the horizontal distance of the cross section of the size of the inner contour of the opening (21) of the female die (2) is D1, and the horizontal distance of the cross section of the outer contour of the part to be extruded (3) is D2, wherein D1 is (1.001-1.200) D2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202120349050.6U CN215845697U (en) | 2021-02-04 | 2021-02-04 | Extrusion rod and extrusion system for compacting inner surface of powder metallurgy part |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202120349050.6U CN215845697U (en) | 2021-02-04 | 2021-02-04 | Extrusion rod and extrusion system for compacting inner surface of powder metallurgy part |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN215845697U true CN215845697U (en) | 2022-02-18 |
Family
ID=80238545
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202120349050.6U Active CN215845697U (en) | 2021-02-04 | 2021-02-04 | Extrusion rod and extrusion system for compacting inner surface of powder metallurgy part |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN215845697U (en) |
-
2021
- 2021-02-04 CN CN202120349050.6U patent/CN215845697U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105014077B (en) | The preparation method of powder metallurgical gear, sprocket wheel | |
| US7854995B1 (en) | High density dual helical gear | |
| US5754937A (en) | Hi-density forming process | |
| CN101905411B (en) | Method for manufacturing coupler for distributor of automobile engine | |
| US4393563A (en) | Cold forced sintered powder metal annular bearing ring blanks | |
| CN109695004B (en) | Manufacturing method of iron-based powder metallurgy part | |
| CN104889403B (en) | A kind of preparation method of iron-based powder metallurgy parts | |
| CN104368816A (en) | Method for manufacturing iron-based powder metallurgy components | |
| US20090129964A1 (en) | Method of forming powder metal components having surface densification | |
| CN105215363A (en) | A kind of preparation method with the copper-base powder metallurgy part of densified surface | |
| CN108500277A (en) | A kind of preparation method of powder metallurgy surface densified parts | |
| US20240157439A1 (en) | Process for manufacturing toroid parts | |
| CN215845697U (en) | Extrusion rod and extrusion system for compacting inner surface of powder metallurgy part | |
| US7364803B1 (en) | High density dual helical gear and method for manufacture thereof | |
| CN105234405A (en) | Preparation method for iron-based powder metallurgy part with compact surface | |
| CN113333755A (en) | Preparation method of powder metallurgy face tooth of angle grinder | |
| CN112792338A (en) | Extrusion rod for compacting inner surface of powder metallurgy part and manufacturing method of part | |
| CN1059303A (en) | The production technology of powder metallurgy for mechanical structure parts | |
| CN1132260A (en) | Method for prodn. of 3-class bearing retainer by use of powdered metal | |
| CN102052459B (en) | Powder-metallurgy release yoke and manufacturing method thereof | |
| CN114367795A (en) | Machining method of automobile gear shifting hydraulic piston rod | |
| CN111590077A (en) | Powder metallurgy car synchronizer gear hub and production method thereof | |
| CN112743078A (en) | Automobile hybrid gearbox clutch inner hub and preparation method thereof | |
| CN105499580A (en) | Manufacturing method for powder metallurgical cylinder | |
| CN114054757A (en) | Powder metallurgy densification part and manufacturing process thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |