The effect of mechanical vibration on the interface micro-structure and mechanical properties of lost foam casting Al-18Si/AZ91D double-alloy has been studied.The results show that the thickness of the inter-metallic compounds (IMCs) layer at the Al-18Si/AZ91D double-alloy bonding interface decreases from 715.7μm to 575.4μm after applying vibration, thereby eliminating the brittle phase existing at the interface; the vibration also eliminates the existence of the Al3Mg2 layer.The coarse primary Si is converted into fine and dispersed Mg2Si; in addition, due to the influence of high Si content, the application of vibration on Al-18Si/AZ91D shows an obvious effect of breaking the oxide film, which is beneficial to reduce the interface defects and facilitate element diffusion.The shear results show that the average shear strength of the Al-18Si/AZ91D double-alloy increases from 49.7MPa to 65.2MPa after applying vibration.
The effects of different holding temperatures and holding times on the micro-structure of Cp/AZ91D composites have been studied, and the evolution process of Cp/AZ91D semi-solid micro-structure has been briefly analyzed.The results show that when the holding temperature is 600℃and the holding time is 60min, the solid-liquid ratio and spheroidization rate of the semi-solid micro-structure are the best.The holding temperature and holding time significantly affect the semi-solid microstructure of Cp/AZ91D composites.
The macroscopic morphology observation, micro-structure analysis, hardness detection and composition analysis of the cracked parts of 45 steel cushion block have been carried out by metallographic microscope, Blovi hardness tester, spark direct reading spectrometer and other equipment.The results show that the type of crack which causes the failure of the cushion block is quenching crack.Due to the existence of a large number of inclusions in the material, the inclusions destroy the continuity of the matrix and cause local stress concentration, while increases the quenching cracking tendency of the material, which is the main reason for the failure of the cushion block.
Taking a vibration conveying shakeout machine as the analysis object, a three-dimensional solid model has been established through SolidWorks software, while the finite element analysis software ANSYS Workbench has been imported to carry out prestress modal analysis and the first 12 modal frequencies of the shakeout machine have been obtained.The harmonic response analysis has been conducted under the vibration force to obtain the amplitude-frequency response cloud diagram of the shakeout table of the vibrating body in the Y-axis direction, which provides a reference for the structural design and optimization of the shakeout machine.
A drying device which utilizes the waste heat of hot air from air compressors, including multiple air compressors, fan rooms and drying rooms, has been introduced in the text.The waste heat outlet of each air compressor is connected with a waste heat air duct.There is a first butterfly valve on each duct, each waste heat duct is connected with pipeline I respectively, and the two ends of pipeline I are provided with second butterfly valves, pipeline I is connected with one end of pipeline II, and there is a third butterfly valve on the connection place between pipeline II and pipeline I.The other end of the pipeline II is connected with the electric fan set in the fan room, and the top of the drying room is set in the fan room.It gives full play to the environmental protection effect of waste gas reuse, which reduces air pollution, improves the production environment of the foundry, saves a lot of gas costs, and reduces production costs.
In view of the fact that there are multiple batches of production of sand core conveying trays on the automatic production line of sand cores in foundries, or the deviation of trays produced in the same batch is large, which exceeds the current positioning accuracy requirements.In addition, the positioning wear is large for a long time of use, and the existing positioning device cannot meet the needs of accurate positioning of the sand core at the current stage.The system enables precise positioning of existing pallets, which reduces production and maintenance costs.
Through the improved design of the traditional core box, it breaks through the current situation that the traditional core box is formed by vibration or hitting the core box body.The impact force of the improved design of the core box acts directly on the core, which not only speeds up the molding speed, but also reduces the damage to the core box caused by repeated blows.The design method is not only suitable for the extrusion of ordinary core boxes, but also suitable for the extrusion of cores with complex shapes and larger friction, which has promotion value.
The automatic control of equipment can not only liberate laborers from heavy manual labor, part of mental labor and harsh and dangerous working environments, but also improve labor productivity.The roller-type automatic V-method production line project produces low-carbon alloy steel track shoes.The control system is the core of the mechanical equipment.The whole line adopts Siemens S7-1500PLC to realize the total control through the PROFINET communication network to meet the rapid adjustment and control requirements of the speed, negative pressure and position of the molding ring.The molding ring has a high degree of automation, advanced technological process, stable and reliable operation, which improves production efficiency & quality, while reduces production, management and manufacturing costs.
A core setting machine used in the automatic iron mold sand coating production line has been introduced.The structural characteristics and functions of the core setting machine manipulator and the sand core conveying roller table have been explained.The working process of the core setting machine has been described.This equipment simplifies the transportation and logistics of sand cores, reduces the labor intensity of workers, and improves production efficiency.
Lost foam casting is a green casting process with nearly no allowance and precise molding.Magnetic separator is a sand treatment production line in lost foam casting to realize automatically casting falling sand, impurity screening, iron bean magnetic separation conveying and old sand conveying& cooling.The key equipment for the recovery and reuse of old sand is closely related to the production cost and its role will become larger and larger with the development of the national foundry industry, the promotion of intelligent manufacturing and the continuous improvement of the level of automatic production technology.Through the transformation of the structure and performance of the magnetic separator in the text, the equipment failure and the production cost have been greatly reduced, while the efficient recovery and reuse of used sand has been ensured and the enterprise competitiveness has been improved.
By increasing the Cr content of the roll, using the Re-Ti-N composite modifier treatment technology, and optimizing the morphology, distribution and quantity of VC and Mo2C carbides, the high-speed steel roll produced has both the hot crack resistance of high-chromium steels and the wear resistance of high-speed steel, which replaces of the commonly used bainitic ductile iron roll in the bar K3 slitting machine with good effect.
Several common repair techniques for high-grade gray iron castings of engine cylinder block and cylinder head have been introduced, including hot welding, cold welding, impregnation, brush plating and the use of cast iron repair agents.The basic principles, equipment & materials used, implementation steps and applicable situations of various repairing techniques of gray cast iron cylinder block and cylinder head have been stated.
The advantages and disadvantages of two different structural designs of the Z9406 core shooting machine which uses hot-coated sand to make the cylinder block crankcase core hot core box have been analyzed and reviewed.The "block type+leakage type" structure has more advantages by comparing with traditional "integral type+suspended type" structure which is the optimal design scheme; the optimal design scheme of the hot-coated sand for the Z9406 core shooting machine to make the hot core box of the cylinder block crankcase core has been guided by the performance theory:the reasonable determination of the block type+leakage mode structure scheme of the hot core box, optimization design of the core box body performance, reasonable design of the exhaust structure block, optimization of the leakage mode structure of the lower box body, optimization of the box opening method and other design contents of the crankcase core have been emphatically introduced.The concept of its optimal design and its wide application has been presented by applying ergonomics, aesthetics and performance techniques.
Semi-steel material is a roll material whose carbon content is between cast iron and cast steel.Semi-steel rolls not only have the high strength and toughness of cast steel rolls, but also have good wear resistance of cast iron rolls.However, in the casting process of the semi-steel roll, the problem of outer circle mottle is easy to occur.Through the detection and analysis of the mottle, as well as a series of improvements, the mottle problem has been successfully solved.
As an important part of a diesel engine, the cylinder head has a very complex structure and requires high casting technology.The structural characteristics and casting process of some type of diesel engine cylinder head have been introduced, and a systematic defect analysis has been carried out according to the actual problems.According to the causes of casting defects, corresponding solutions have been proposed, so as to effectively solve the problems and improve the product quality.
Super large hot-rolled H section steel play an increasingly important role in the construction of the national economy, and its rolling cannot be separated from super large horizontal roller rings.In the development of super large horizontal roll rings, the composition segregation has been eliminated through multi-layer composite technology and dynamic effect technology; the casting and thermal stress of the roll ring have been eliminated through two heat treatments.The successful development of the world's largest section steel horizontal roll ring helps some domestic section steel enterprise become the first in the world to produce 1100mm super large H-section steel, which fills the international gap.
Industrial electric furnaces are developing in the direction of large capacity, rapid melting and more energy saving.At the same time, it also brings unfavorable factors such as small load, low power factor and poor temperature control when high-power power supply is used for the oven.Therefore, a set of furnace power supply has been added to the industrial electric furnace alloy melting system, while the design method and implementation method have been given.The scheme has been applied in some foundry stainless steel plant which achieves good results.
Taking the aluminum alloy flywheel housing as the research object, the process of squeeze casting has been adopted and a more reasonable pouring system has been designed.The numerical simulation software ProCAST has been used to simulate and analyze the EN AC-46000 aluminum alloy flywheel housing, while the numerical simulation of the filling and solidification process of the castings has been carried out.The results show that the alloy liquid does not solidify in sequence, resulting in shrinkage porosity defects.According to the simulation results and the shrinkage porosity generation area, a cooling system has been added to eliminate most of the defects which provides a reasonable solution for production.
In order to reduce the manufacturing cost of the pump, relying on the MAGMA simulation technology, a dual-phase steel pump casing casting process with low cost has been developed, which reduces the manufacturing cost of the pump casing, the material cost by 44%, and the labor cost by 62%.It greatly enhances the market competitiveness of enterprises.
For the front end cover casting of the new energy motor shell, it is difficult to achieve sequential solidification if the wall thickness difference is large, and the overall thin wall thickness is not conducive to the floating of exhaust gas and oxide slag.By use of computer simulation of the original plan, it is found that the gas and oxide slag at the end of the filling of the casting need to return to the top riser through the filled cavity, resulting in pores and slag inclusion defects in the casting.In the process of solidification, the riser cannot feed the hot joint at the through hole in the center of the casting, and there is a tendency to form shrinkage defects.Since the thin wall of the casting is not processed which has a grid rib structure, it is impossible to set up process subsidies, so a riser is set on one side of the casting.The filling process is adjusted so that the cavity is tilted from vertical to horizontal, and the feeder gravity pressure head is used to provide supplementary pressure after tilting.The optimization scheme has been simulated and the castings have been filled smoothly.The gas and oxide slag can be discharged through the riser and the hot spots during the solidification process can be fed through the riser, while the shrinkage porosity defect can be solved.Production verification castings are free of casting defects and the process yield has been improved.
The triethylamine cold-core core-making process is widely used in the foundry industry due to the high dimensional accuracy and high final strength of the sand core.The difficulty of the cold core process is that veining defects are easy to appear at the rounded corners, planes and high-temperature hot joints of the casting cavity, which affects the cleanliness of the cavity.The common methods to prevent the occurrence of veining are adding non-quartz series sand or anti-veining agent to the core sand, coating the surface of the sand core with anti-veining paint, etc.[1].By studying the characteristics of the anti-veining agent and its influence on the strength of the sand core and the size of the casting, the application of the cold-core anti-veining agent added to the cylinder head airway core has been explored, which provides reference for the majority of workers engaged in cylinder head casting technology research.
As one of the main and basic industries of the global manufacturing industry, informatization, dataization and intelligence have gradually penetrated into all aspects of modern foundry factories.In the production of green sand mechanized molding process, The way to deeply integrate data with high-yield and high-quality castings and realize intelligent control has been put forward, as well as the origin, the way and use of data.The way to realize the data into foundry production which plays the role of intelligent control has been introduced from various aspects.
The problems of chaotic production site management, weak safety awareness of employees, and poor equipment in the foundry industry are still prominent.The level of institutionalization, standardization and standardization of safety production is still low, and safety production accidents occur from time to time.In order to ensure the safe development of the foundry industry, it is necessary to further promote the construction of double prevention mechanisms, and build "two lines of defense" for risk classification management as well as hidden danger investigation and management.The background significance, process method and creation effect of the double prevention mechanism in the foundry industry have been explored and studied in the text.The results show that the construction of the double prevention mechanism can promote the self-discrimination & self-control of safety risks, and self-inspection& self-inspection of hidden dangers in foundry enterprises, which realizes source control, treatment of both symptoms and root causes.It has important guiding significance in preventing safety accidents.
Innovation is very important for enterprises.The essence of innovation is to search for knowledge, and knowledge is the basis of innovation.Under the new competitive background, the innovation of enterprises is the innovation of knowledge in the final analysis.Aiming at the problems encountered in the extrusion process of magnesium alloy profiles, by comprehensively using the knowledge of industrial engineering related theories and Triz theory, a cross-domain knowledge search technology has been proposed.Enterprises are encouraged to cross the field restrictions when encountering process optimization problems, in order to obtain more heterogeneous knowledge and apply it in this field, which greatly improves the efficiency in solving process optimization problems and their innovation & creativity capabilities.
Wear-resistant materials are widely used in various fields of industrial production.As a big industrial country, we consumes huge metal materials due to industrial production every year.There are many problems in national wear-resistant material industry, which has a very broad prospect.The development status and problems of national wear-resistant material have been briefly expounded.At the same time, in combination with the development prospects and opportunities of the industry, some views and suggestions on the future development direction of national wear-resistant materials industry have been put forward.
