71results about "Mandrels" patented technology

The invention discloses a rolling and expanding bidirectional laminating method for a layered bimetal composite hollow shaft, which is characterized in that an outer shaft and an inner shaft which are made of metal materials are in interference fit to obtain an initial composite hollow shaft; then the initial composite hollow shaft is fed into a three-roller skew rolling mill, when a roller performs skew rolling on the initial composite hollow shaft, the reaming rod extends into an inner hole of the initial composite hollow shaft at the same time, and the outer diameter of the reaming rod is larger than the diameter of the inner hole of the initial composite hollow shaft; the initial composite hollow shaft is subjected to bidirectional compression in the radial direction by the roller and the reaming rod during rolling; the initial composite hollow shaft is pushed forwards in the axial direction, meanwhile, the axial relative position of the roller and the reaming rod is kept unchanged till lamination rolling of the whole composite hollow shaft is completed, and the layered bimetal composite hollow shaft is obtained; the device has the advantages that during rolling, the roller and the reaming rod simultaneously compress the composite hollow shaft inside and outside in the radial direction, and the bonding strength of the composite hollow shaft is remarkably improved.

The utility model discloses a heat-resistant and wear-resistant piercing plug with high stability, which comprises a plug body, a connecting rod arranged at the bottom of the plug body, a liquid conveying pipe arranged inside the connecting rod, a cooling cavity arranged inside the plug body, a fixing rod fixedly connected with the inner wall of the plug body, a reinforcing plate fixedly connected with the outer side of the fixing rod, and a water outlet arranged on the inner wall of the plug body. The bottom of the plug body is fixedly connected with the heat insulation layer, the outer side of the connecting rod is fixedly connected with the fixing cylinder, the inserting rod is arranged on the fixing cylinder, and the sliding cylinder is arranged on the outer side of the connecting rod and fixedly connected with the two ends of the sliding rod. Cooling is carried out through the cooling cavity, instability of the ejector head caused by high temperature is avoided, abrasion of the ejector head is reduced, the strength of the ejector head is enhanced through cooperation of the fixing barrel and the reinforcing plate, the sliding barrel is pushed to enable the connecting rod to move in the sliding groove, the inserting rod is driven to be separated from the inserting hole, and then the ejector head body can be disassembled. The dismounting difficulty of the plug body is reduced.

The application provides a cold rolling method for reducing surface cracks of TC4 titanium alloy seamless pipes, relates to a cold rolling pipe manufacturing technology in the metallurgical and mechanical industries, and comprises the following steps: adopting a two-roller cold rolling machine to roll a blank with a specification of Ф76*7.5mm into a finished product with a specification of Ф25*3mm. When rolling, the left and right openings of the groove are designed to be asymmetric, Fx1 and Fx4 are constant, the sizes of Fx2 and Fx3 are 0.1mm larger than those of Fx1 and Fx4, and the sizes are used to accommodate part of the long axis of the cross-section ellipse of the seamless pipe; meanwhile, the opening angle is constant, and the opening angle Fw2 is 5° larger than Fw1. Through optimization of the deformation tools such as the mandrel and the roller groove, reasonable adjustment of the feed amount and the rotation angle, the occurrence of the effective inner and outer surface cracks is effectively reduced. According to the characteristics and technical requirements of different TC4 titanium alloy seamless pipes, the cold rolling pipe manufacturing process is organized and implemented, the surface defect loss of the titanium alloy pipe is reduced, the surface rolling quality is continuously and stably improved, and the energy saving, emission reduction and consumption reduction effects are remarkable.

The invention provides a metal middle core rod and a manufacturing method thereof, and belongs to the technical field of core rod machining. The metal middle core rod comprises a core rod body and a core rod head, the core rod head is arranged at one end of the core rod body, a stress reducing mechanism is arranged in the core rod body and comprises an air inlet channel, a first heat dissipation channel and a first channel, the air inlet channel is formed in an inner cavity of the core rod body and used for introducing high-pressure air, a spiral air return channel is further formed in the inner cavity of the core rod body, and the first heat dissipation channel is communicated with the first channel. And an exhaust nozzle is arranged on the surface of the core rod body, and the exhaust nozzle is communicated with the air return channel. According to the invention, the temperature in the temperature sensing cavity is gradually increased through the arrangement of the stress reducing mechanism, so that the bimetallic strip is deformed and bent downwards, the sliding plate and the cross are pushed to gradually move upwards, the first channel is gradually conducted by the first sealing plate, and the cooling liquid can enter the first heat dissipation channel for liquid cooling heat dissipation; the larger the cooling liquid flow in the first heat dissipation channel is, the heat dissipation effect is guaranteed, and the thermal stress on the surface of the core rod body is reduced.

The present invention relates to a high temperature forming tool (1), at least part of which consists of a molybdenum-based alloy having a molybdenum content of ≥ 90 wt.%, the molybdenum-based alloy being in a compacted and sintered state and having a thermal shock resistance of at least 250 K in the compacted and sintered state, where the thermal shock resistance is R eH is defined as the quotient of / (α·E), and R eH is the yield point at room temperature in MPa, α is the coefficient of thermal expansion in 1 / K, and E is the elastic modulus in MPa.

The utility model discloses a steel pipe perforating and rolling tool which comprises a perforating and rolling tool body, the perforating and rolling tool body comprises a connector, one end of the connector is fixedly connected with a connecting pipe, an opening is formed in the middle of one end of the connecting pipe, a threaded pipe is arranged in the middle of the opening, and an ejector rod is arranged in the middle of the threaded pipe in a threaded mode. A butt joint structure is further included, the butt joint structure comprises a butt joint pipe, a threaded ring is arranged on the outer surface of the butt joint pipe in a threaded mode and extends into the connector, rectangular protrusions are arranged on the outer surface of the threaded ring at equal intervals, and a butt joint column is arranged in the middle of the butt joint pipe. According to the utility model, while being easy to disassemble and assemble, a damaged structure can be independently overhauled and maintained, so that the cost is reduced, the axial force of the ejector rod is increased, so that the use requirement is better met, the bending damage probability of the ejector rod is reduced, and the cost is further saved; and subsequent thread slipping or breakage can be avoided, so that disassembly and replacement of the ejector rod are not affected, and the use effect is improved.

Device (10) for handling mandrel bars (3) in a rolling plant (1) with a rolling mill (20) for rolling seamless pipes (2'), the device (10) having a pusher (11) for moving a mandrel bar (3) arranged in a rolling line (L) in a rolling direction (R) so that the mandrel bar (3) can be fed from a basic state into a pipe blank (2) arranged before the mandrel bar (3) in the rolling direction (R), a holding apparatus (12) with a stationary unit (12a) movable along the rolling line (L), which holding apparatus is arranged to temporarily fix the mandrel bar (3) at a point of action (3c) in the area of a rear end (3b) of the mandrel bar (3) and to perform a working stroke starting from a starting position (xA) in the rolling direction (R) and against the rolling direction (R), whereby the mandrel bar (3) can be driven into the rolling mill (20) in the rolling direction (R) and can be pulled out of the rolling mill (20) against the rolling direction (R) by the holding apparatus (12), characterized in that the holding apparatus (12) is such that the stationary unit (12a) in the starting position (xA) in the basic state is located between the two ends (3a, 3b) of the mandrel bar (3). A ​

The application provides a wear-resistant composite piercing mill head manufacturing method and a piercing mill head, and the manufacturing method comprises the following steps: S1, preparing a steel base head; S2, adopting a submerged-arc welding process to make a flux-cored wire cladded on a working cone surface and a nose end surface of the steel base head, so as to form a cladding layer with a thickness of 6-8 mm; and S3, pre-oxidizing the cladding layer of the steel base head at high temperature, so that the wear-resistant composite piercing mill head is obtained. The wear-resistant composite piercing mill head manufacturing method has a dense and uniform oxide film on the surface of the cladding layer of the piercing mill head, the oxide film is firmly combined with the cladding layer, and the existence of the dense and uniform oxide film can reduce the power consumption of a steel pipe piercing mill and prolong the service life of the piercing mill head.

The invention belongs to the field of metal materials, and relates to a long-life temperature-resistant anti-crack composite plug and a preparation method thereof. According to the invention, through elaborate design of components of the metal layer, excellent hardness and wear resistance are provided, the material is suitable for high-temperature and high-wear working conditions, and by adding a proper amount of RE and Ni, the plasticity and toughness are improved while the material strength is improved, the service reliability is remarkably improved, and the service life is remarkably prolonged; an asymmetric thermal field which is fast in internal cooling and slow in external cooling is constructed, high-quality interface bonding and a compact structure are achieved in the composite casting process, a surface pressure stress field beneficial to crack resistance is formed in the service process, thermal stress concentration is effectively relieved, generation and extension of thermal fatigue cracks are restrained, and the service life of the composite casting is prolonged. And the service life, temperature resistance and crack resistance of the composite plug are improved.

The invention discloses a core rod circulating cooling method for a CPE (chlorinated polyethylene) pipe jacking unit, a core rod comprises a section II, and the method comprises the following steps of: backwards conveying the core rod subjected to rod stripping treatment in a steel pipe production process, and feeding the core rod into a core rod forced cooling device for forced cooling in the conveying process so as to reduce the core rod to a target temperature T0; the core rod forced cooling device comprises a plurality of forced cooling areas, each forced cooling area is sequentially divided into a front forced cooling section and a rear forced cooling section from front to back, the temperature T1 of a core rod II section is collected between core rod stripping treatment and entering of the front forced cooling sections, and a first forced cooling strategy is executed in the front forced cooling sections: when T1 is larger than or equal to 650 DEG C, water cooling is conducted on the surface of a core rod according to the set maximum cooling flow; when T1 is larger than or equal to 600 and smaller than 650 DEG C, the surface of the core rod is subjected to water cooling according to the set intermediate cooling flow; and when T is larger than or equal to 550 DEG C and smaller than 600 DEG C, water cooling is conducted on the surface of the core rod according to the set minimum cooling flow. By means of the method, the core rod can be effectively cooled, abrasion and consumption of the core rod are reduced, and the steel passing service life of the core rod is prolonged.

The utility model relates to the technical field of cooling equipment, and discloses self-circulation cooling equipment for manufacturing seamless steel pipes through hot punching, which comprises a fixing plate, a water tank, a cooling device, a cooling device and a control device, and is characterized in that the bottom end of the fixing plate is fixedly provided with the water tank; the cooling mechanism is arranged at the bottom end in the water tank; wherein the cooling mechanism comprises a liquid pump, and a two-way pipe is fixedly connected into the top end of the liquid pump in a sleeved mode. According to the self-circulation cooling equipment, a set of complete water circulation system is constructed, cooling water is not directly discharged like a traditional mode after the task of cooling the ejector rod is completed, but returns to the water tank again to be recycled, and the design enables the utilization rate of water resources to be greatly improved, so that the cost is reduced, and the service life of the ejector rod is prolonged. Dependence on an external water supply system is greatly reduced, the water supply pressure of a water resource shortage area is effectively relieved, and due to the fact that cooling water is recycled, discharge of a large amount of sewage containing impurities and high temperature is reduced.

The utility model discloses a core rod conveying and pushing mechanism for seamless tube processing, which comprises a core rod pressing mechanism, a core rod conveying mechanism and a core rod pushing mechanism, the core rod pressing mechanism and the core rod conveying mechanism are crosswise arranged from top to bottom, the core rod pushing mechanism is positioned on the rear side of the core rod conveying mechanism, and the core rod pushing mechanism is positioned on the rear side of the core rod conveying mechanism. The core rod pressing mechanism comprises a pressing oil cylinder, a pressing rack and a fixed rack, the core rod conveying mechanism comprises a conveying motor, a conveying speed reducer, a universal coupling, a gear shaft, a driving gear, a driven gear, a driving conveying roller and a driven conveying roller, and the core rod pushing mechanism comprises a lifting oil cylinder, a pushing oil cylinder and an oil cylinder support. The mandrel can be automatically clamped, pushed and separated, rapid feeding and discharging of pierced billets are facilitated, the rolling rhythm is compact, the rolling period is shortened, and the production efficiency is improved.

The present invention discloses a self-lubricating and forming inner core device suitable for the cold rolling of stainless steel tubes using hydrogen energy, comprising an inner forming core and a self-lubricating arrangement attached to one end of the inner forming core, wherein a flow channel is arranged on the inside of the inner forming core and several lubricating fluid holes are arranged on the surface of the inner forming core, wherein several lubricating fluid holes increase stepwise along the inner diameter of one end away from the self-lubricating arrangement, wherein the self-lubricating arrangement comprises a pump box, a fluid storage tank, a diverting valve assembly and a movable shaft assembly as well as several movable partitions on the inside of the pump box, wherein one side of the pump box is fixedly connected to a guide cap.The design of the self-lubricating and forming inner core device in the present invention ensures that the lubricating fluid is distributed evenly and continuously on the surface of the inner core, particularly at the end furthest from the lubrication source. Optimizing the distribution and size of the lubricating fluid holes significantly improves the lubrication between the inner core and the inner wall of the stainless steel tube, thereby reducing friction and wear during processing and improving the accuracy and surface quality of the stainless steel tube during cold rolling.

An inclined rolling apparatus is provided to prevent shape defects in the front and rear unstable portions of a seamless tube blank. An inclined rolling apparatus includes an inclined piercing mill for piercing rolling and an inclined outer diameter mill connected after the inclined piercing mill, wherein the distance LS (mm) between the rolling portion of the piercing roll and the rolling portion of the outer diameter roll satisfies the following equation (1), and the roll spacing DS of the plurality of outer diameter rolls satisfies the following equation (2): 3×(1.2PO+2G)≤LS≤0.8BL…(1) 1.2PO+2G>DS≥DB+2G…(2) In equations (1) and (2), PO is the outer diameter of the mandrel (mm), G is the spacing between the mandrel and the piercing roll (mm), BL is the length of the rod (mm), and DB is the outer diameter of the rod (mm).

A three-roll tilt roll forming method is disclosed that increases the number of times and the time for finishing the surface of the forming area of ​​the rolled member by the rolling rollers during the rolling process, effectively reduces defects of spiral marks on the surface of the rolled member, ensures the mechanical properties of the hollow shaft system member, reduces the finishing allowance in subsequent machining, and reduces material waste. [Solution] The rolling rollers of a three-roll inclined rolling mill are installed in a drum shape, and the shape of the rolling rollers is optimized so that the rolling rollers and the rolling member are always in line contact with each other at any time in the Cartesian coordinate system of the rolling rollers during the rolling process. During rolling, the reduced diameter section of the tube material rolled member is first rolled, then the straight shaft section is rolled, and finally the expanded diameter section is rolled, and finally the finished rolled member is obtained. This method is characterized by optimizing the shape of the rolling rollers so that the rolling rollers and the rolling member are always in line contact with each other at any time in the Cartesian coordinate system of the rolling rollers during the rolling process.

The utility model relates to the technical field of metal pressure processing, in particular to a flow guide optimized tube blank punching efficient top head structure which comprises a top head, and the inner wall of the top head is fixedly connected with a plurality of round fixing plates which are arranged in parallel. A good heat dissipation system can be formed by the connecting pipes on the surfaces of the round pipes, the spiral heat dissipation pipes and the partition plates in the spiral heat dissipation pipes. The heat dissipation area is increased through the spiral heat dissipation pipe, heat generated by the plug in the working process can be rapidly dissipated out, and the plug is kept within the proper working temperature range. Meanwhile, although the tungsten carbide coating on the surface of the plug is only 5 microns, tungsten carbide has the characteristics of high hardness and strong wear resistance, so that the wear resistance and corrosion resistance of the surface of the plug can be greatly enhanced, the service life of the plug is prolonged, and the problems of cost increase and production interruption caused by frequent replacement due to wear and corrosion of the plug are reduced; and continuity and stability of production are guaranteed.

The invention discloses a perforating machine background center line calibration tool and method.The perforating machine background center line calibration tool is arranged between a perforating main machine and an ejector rod trolley, the perforating machine background center line calibration tool comprises centering devices, an adjusting assembly and a calibration frame, and the adjusting assembly is arranged between the centering devices and used for adjusting a perforating machine background; according to the three-roller core holding device, the deviation values of the station center line and the rolling center line in the horizontal direction and the vertical direction are calibrated, the calibration precision is high, the consistency of the measurement precision is effectively guaranteed, and meanwhile the consistency and the interchangeability of the three-roller core holding device can be effectively guaranteed.

This invention relates to a high-efficiency piercing device, comprising a platform and a feeding mechanism. A piercing mechanism is located at the tail end of the feeding mechanism, a transfer mechanism is located on one side of the piercing mechanism, and a cooling mechanism is located at the tail end of the transfer mechanism. Unloading mechanisms are located on both sides of the feeding mechanism. The piercing mechanism includes a support component, a top support component a, and a top support component b. The transfer mechanism includes a rodless cylinder and a rotating component. The cooling mechanism includes a water spray component and a switching component. The feeding mechanism drives the stainless steel round bars to be pierced under the action of the top support components a and b. The rodless cylinder moves to switch the work positions of the top support components a and b. The rotating component, in conjunction with the feeding mechanism, transfers the stainless steel round bars to the unloading mechanism. The unloading mechanism is used to unload the stainless steel round bars. The switching component controls the water spray component to cool the top support components a and b sequentially. This invention solves the problems of long processing intervals, poor continuity, and low efficiency in traditional technologies.

To provide a model generation method, a model generation device and a life determination method of a tool for hot rolling which can generate a model capable of objectively determining a life of a tool for hot rolling in a short time.SOLUTION: A model generation method for generating a model for determining a life of a tool for hot rolling includes: an image acquisition step of acquiring an image obtained by photographing appearance of a tool for hot rolling; a label designation step of imparting at least one label among a plurality of labels predetermined for the appearance in the image; and a generation step of generating a learned model by machine learning with the appearance as an explanatory variable and at least the one label as an objective variable, using the image to which at least the one label is imparted.SELECTED DRAWING: Figure 1

The utility model discloses a die for accurately controlling the outer diameter of a hot-rolled seamless steel pipe, which relates to the technical field of seamless steel pipe processing and comprises a workbench, a clamp disc slidably mounted on the workbench, a die rod clamped and mounted on the clamp disc, a sliding frame slidably mounted in a through groove, and a rotating ring rotatably mounted in the sliding frame. A square frame is fixedly mounted in the rotating ring, mounting frames are movably mounted on the four edges of the interior of the square frame, extrusion rollers are rotationally mounted in the four mounting frames, hydraulic cylinders are fixedly mounted on the four edges of the exterior of the square frame, a gear ring is fixedly mounted on the outer ring of the rotating ring, and a third motor is fixedly mounted at the top end of the sliding frame; according to the seamless steel pipe extrusion die, the die rod with the corresponding size is inserted into a seamless steel pipe in a penetrating mode according to the inner diameter size of the seamless steel pipe before the seamless steel pipe is extruded, and the inner diameter of the seamless steel pipe can be prevented from being reduced during extrusion.

The invention relates to the field of forming tools for metal extrusion, in particular to an ejector head for seamless steel pipe extrusion forming and a manufacturing method of the ejector head. The top for extrusion forming of the seamless steel pipe comprises a top body (1) and is characterized in that the top body (1) comprises a top tip (2), a top body (3) and a top tail (4), the outer side face of the top body (3) is sequentially provided with at least three annular heat dissipation grooves (31), the outer side face of the top body (1) is covered with an oxidation layer (32), the oxidation layer (32) fills all the heat dissipation grooves (31), and the outer side face of the oxidation layer (32) forms a smooth face. The manufacturing method of the plug for extrusion forming of the seamless steel pipe is implemented after a workpiece is prepared, and is characterized by being implemented according to the following steps in sequence: a, pretreatment; b, accurate carburization; c, accurate oxidation; d, cooling; and e, performance optimization and detection. The device is convenient to manufacture and long in service life.

The application provides a center line measurement method for a three-roller centering device of a bacterial piercing machine, which comprises the following steps: step 1, setting a center reference line, the height of the center reference line is flush with the center point of the entrance, and the center reference line is used as the center reference line; step 2, measuring the distance from the oil hole of the lower clamp roller of the two three-roller centering devices to the center reference line, and adjusting the lower clamp roller pull rod of the three-roller centering device, so that the distance L1 from the oil hole of the lower clamp roller of the east three-roller centering device to the center is equal to the distance L2 from the oil hole of the lower clamp roller of the west three-roller centering device to the center, and the distance L1 and the distance L2 are equal to a first preset value; step 3, clamping the upper clamp roller of the three-roller centering device to a clamped state; measuring the distance of the connecting line between the oil holes of one upper clamp roller and two lower clamp rollers, and adjusting the upper clamp pull rod, so that S1, S2 and S3 are equal to a second preset value. The method can simply, conveniently and quickly measure the center line of the three-roller centering device, guarantee the piercing wall thickness precision and improve the physical quality of products.

The application provides a high-toughness seamless pipe mandrel steel, a produced seamless pipe mandrel and a heat treatment process, and the components include C, Si, Mn, Cr, Mo, V, Ni, Al, Ti, P, S, N, O, the rest is Fe and other inevitable impurities, the components satisfy 60xC+10xMn+12xSi+20xCr+25xMo+32xV >=225, 50x(N-2.1xAl-3.4xTi) / 14 >=0.015, (63xNi+25xV+22xMo)+(3.6xV+6.5xMo)x120xN >=155. After the heat treatment of the steel provided by the application, the steel has good toughness and high-temperature fatigue performance, the thermal fatigue life is >=4200 times, and the service life of the pipe mandrel is greatly improved.

The utility model relates to the technical field of hot-rolled seamless steel pipe production equipment, and discloses a cooling system for a hot-rolled seamless steel pipe continuous rolling core rod, which comprises a fixing frame, a water tank fixedly connected to the upper surface of the fixing frame, flow dividing pipes fixedly connected to the left side and the right side of the water tank, and cooling branch pipes fixedly connected to the bottoms of the flow dividing pipes. The bottom ends of the cooling branch pipes are in threaded connection with threaded cylinders, the bottoms of the threaded cylinders are fixedly connected with sprayers, supporting rings are fixedly connected into the sprayers, the upper surfaces of the supporting rings are fixedly connected with elastic rubber rings, and filter covers are arranged above the elastic rubber rings. According to the cooling device, the cooling branch pipes made of high-temperature-resistant engineering plastics are adopted, blockage caused by rusting in the pipelines or influence on the flushing and cooling effect on the core rod are avoided, cooling liquid at the spraying position can be completely filtered through cooperation of the threaded cylinder, the supporting ring, the elastic rubber ring and the filtering cover, and the cooling effect is improved. And the nozzle is prevented from being blocked by mixed impurities in cooling liquid.

The present invention relates to a system (100) comprising a mobile unit (110) and an activation unit (140). The mobile unit (110) is equipped with at least one actuating member (120), the actuating member (120) being operable by an actuator (130) arranged on the mobile unit. The activation unit (140) comprises an operating mechanism (150) for operating the actuator for the actuating member (120). In order to simplify, reduce costs and make the energy supply to the actuator for actuating the actuating member on the mobile unit more flexible, the present invention provides a system according to the above-mentioned known system in which the activation unit (140) is fixedly assembled on the mobile unit and the system comprises at least one pulling element (160) for transferring the kinetic energy of the operating mechanism (150) in the form of a pulling force to the actuator (130) arranged on the mobile unit (110) for actuating the actuating member (120).

The invention discloses a long-life top head structure which comprises a top head body, cooling medium channels distributed in a net shape are arranged on the inner side of the circumferential outer surface of the top head body and close to the circumferential outer surface, a cooling medium inlet is formed in the axial tail end of the top head body, and a cooling medium outlet is formed in the axial head end of the top head body. And the cooling medium channel is connected between the cooling medium inlet and the cooling medium outlet. The invention further discloses a using method of the long-service-life plug structure, and when the plug body is subjected to perforating operation, the cooling medium is injected into the cooling medium channel through the cooling medium inlet so as to cool the plug body. According to the long-service-life plug structure and the using method thereof, the efficient cooling effect is achieved, the thickness of an oxidation film on the surface of the plug is increased through the oxidability of a cooling medium, and the service life of the plug is remarkably prolonged.

The application discloses a large-diameter-wall-ratio duplex stainless steel pipe and a piercing method thereof, and comprises the following steps: blank heating and rolling, the blank after cutting and removing the surface oxide skin is segmented heated, so that the rolling temperature rise and the heating temperature rise are offset to each other; hot piercing, the blank after the heating and rolling is arranged on a piercing mill to perform piercing, and a large-diameter-wall-ratio hollow shell pipe is obtained; water cooling, the obtained hollow shell pipe is water cooled and cold rolled, and a finished seamless steel pipe with smooth surface and no crack in the inner hole is obtained. Through the blank heating and rolling, heat treatment and water cooling mode, by adjusting the burner power, the blank is non-isothermally heated, the rolling temperature rise and the heating temperature difference are offset, the relatively constant temperature rolling is realized, the top head utilizing the cavity gap is arranged, and the process parameters suitable for the top head are selected, so that the stainless steel seamless pipe with the diameter-wall ratio greater than 15 can be pierced.

This invention discloses a circulating cooling method for mandrels used in CPE pipe jacking units. The mandrel includes a II section. The method comprises the following steps: after mandrel removal during the steel pipe production process, the mandrel is conveyed backward and fed into a mandrel forced cooling device during the conveying process to reduce the mandrel to a target temperature T0. The mandrel forced cooling device includes multiple forced cooling zones, which are divided into a front forced cooling zone and a rear forced cooling zone from front to back. The temperature T1 of the mandrel II section is collected between the mandrel removal process and the entry into the front forced cooling zone. In the front forced cooling zone, a first forced cooling strategy is implemented: when T1 ≥ 650℃, the mandrel surface is water-cooled at a set maximum cooling flow rate; when 600 ≤ T1 < 650℃, the mandrel surface is water-cooled at a set intermediate cooling flow rate; when 550℃ ≤ T < 600℃, the mandrel surface is water-cooled at a set minimum cooling flow rate. This method can effectively cool the mandrel, reduce mandrel wear and consumption, and improve the mandrel's steel life.

This invention discloses a rolling mill adjustment device and method, relating to the field of bimetallic composite tube forming, to solve the problem that it is impossible to manually align the mandrel axis with the rolling centerline of the three rolls and guide plate in a three-roll skew rolling mill. The device includes: a mandrel passing through a support positioning device, the three-roll skew rolling mill, and another support positioning device, aligning the direction of the line connecting the support centers of the two support positioning devices, the mandrel axis, and the rolling centerline; the support positioning devices provide circumferential positioning and support height adjustment for the mandrel; a first distance measuring device is installed on the rolls, and a second distance measuring device is installed on the guide plate; the measurement paths of the first distance measuring device for each distance measuring the distance from the roll to the mandrel surface and the measurement paths of the second distance measuring device for each distance measuring the distance from the guide plate to the mandrel surface intersect with the mandrel axis; a controller is connected to the support positioning device, the first distance measuring device, the second distance measuring device, and the three-roll skew rolling mill to adjust the positions of the support positioning device, the rolls, and the guide plate.

The invention provides a molybdenum alloy plug and a preparation method and application thereof, and particularly relates to the technical field of powder metallurgy. According to the preparation method of the molybdenum alloy plug, a molybdenum source and doping phase powder are mixed through material mixing to obtain molybdenum alloy powder, then the molybdenum alloy powder is pressed into a blank through a staged pressure increasing system and a staged pressure relieving system in the cold isostatic pressing process, the blank is subjected to low-temperature pre-sintering and high-temperature densification treatment after shaping treatment, and the molybdenum alloy plug is obtained. And later-stage annealing is assisted, so that the molybdenum alloy plug is obtained. The preparation method is simple in technological process and low in cost, and the prepared molybdenum alloy plug product has the characteristics of high density, excellent hardness and toughness, long service life and safe and reliable strength. The invention further provides the molybdenum alloy plug prepared through the preparation method and application of the molybdenum alloy plug.