New casting products, materials and processes in J

2022-06-24
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In 2001, Japan cast new products, new materials and new processes

castings are the main structural parts of mechanical and electrical products, and also involve various industrial departments and daily cultural life. Therefore, the casting industry must continuously improve the quality, develop new products, adopt new processes and materials according to the requirements of user development, and further provide new castings for product improvement (improving performance, service life and reducing cost) in cooperation with users. In addition, it should actively put forward suggestions to promote the improvement and development of service object products. Therefore, the continuous development of new products, new materials and new processes, combined with the survival and development of the casting industry, is a very important link. All parties concerned must pay full attention to it

a Japanese economics professor once said; Two thirds of the mechanical and electrical products exported by Japan are made of castings and forgings. Therefore, the level of castings and forgings is an important factor in determining the rise and fall of Japan's exports. Due to the overall economic downturn, Japan's casting output has been reduced year after year, but it is still one of the powerful countries in the production of castings and forgings, and there are continuous new developments. Japan's plain materials publish new products in the first issue of each year, introducing the new products, new materials and new processes of various manufacturers. The new casting products published in the first issue of "plain materials" in 2002 are translated and introduced in order to attract the attention of all parties

I. nodular iron frame for fixing soil

the frame for fixing soil is mainly used to stabilize the slope of earthwork and prevent the collapse and landslide of natural slope. In the past, the construction method site was on the slope, and the concrete and well shaped beam were formed on site. In recent years, in order to shorten the construction period and improve the quality, the concrete precast frame was used, and on this basis, the bar frame made of resin, steel and other materials was widely used for lightweight. On the other hand, in recent years, due to the importance attached to environmental protection and the landscape after construction, we hope not to give people? quot; artificial The purpose of this study is to make use of the high strength and free-form characteristics of ductile iron to develop a process that not only meets the requirements of greening, but also has the advantages of weight and ease of construction, but also is a particularly reliable high-performance product. The frame has a bottom plate and upright bones and muscles, which is convenient for greening, covering soil and setting soil bags. There are through holes near the bottom plate, which is convenient for drainage Water can also make the roots of plants and trees stretch down into the soil for better growth. With the frame, there is also a nodular iron ball seat, which can freely adjust the anchor and angle

ductile iron frame drawing

technical indicators:

design mechanical properties

248kn~62kn

weight

330kg~700kg

compression area

1 3

schematic diagram for adjusting the fixed angle

II. Large stator pressing plate of Austenitic Ductile Iron

in order to improve the power generation efficiency and simplify the structure of super large generator, it is a good idea to use non-magnetic materials to manufacture the flange for tightening the stator. In order to make the flange have the necessary strength and specific magnetic field conductivity, and the internal and external quality meet the requirements, it is made of Austenitic Ductile Iron, but the manufacturing of such castings has the following difficulties

◇ graphite and matrix structure are more sensitive to wall thickness than ash Nanjing University of technology has been committed to γ- PGA and ε- PL basic and industrial research castings are high

◇ it is difficult to ensure the mechanical and physical properties of the body

◇ it is necessary to use the same mouth as the steel casting, which makes it more difficult to ensure the performance of the body

◇ as it is a non-magnetic material, only radiographic inspection can be used to confirm the internal integrity

to ensure the soundness of macro structure, internal shrinkage cavity and surface wrinkle are not allowed. It is easy to produce massive graphite and carbide when the wall thickness part solidifies. This tendency will be stronger at the riser position due to the slower cooling. This is the main reason for the deterioration of the strength and specific permeability of the whole casting; Single as cast γ The phase is difficult and must be heat treated. In order to ensure the strength and specific permeability of the body and prevent the magnetic deformation and deformation caused by stress, it is necessary to γ Chemical sum γ Layer stabilization; Stress relief annealing will change the matrix structure

the main wall thickness of the flange of the tightening stator: 130mm weight as cast: 7000kg

III. the double-layer cylinder sleeve for high-speed diesel engine - the long size double-layer casting technology and the special surfacing design are combined

the thin-wall cylinder liner with small caliber for high-speed diesel engine adopts the blank of long size cast double-layer pipe to realize lamination. The outer layer is made of high-strength cast steel with high strength and high reliability. The inner layer is made of high phosphorus cast iron to ensure the traditional sliding wear characteristics. It is formed by centrifugal casting and adopts special double-layer pipe casting technology to completely integrate the inner and outer layers. The cylinder liner has an inner diameter of 280, a maximum outer diameter of 390 and a length of 650. The casting blank is 250mm long, and the error of bimetal interface diameter is controlled within 2mm. The flange part of the cylinder liner is made of special surfacing on the outside of the casting. When the surfacing conditions are designed, the thermal effects on the double-layer blank pipe are controlled

IV. low thermal expansion cast steel

invar alloy and super invar alloy with good machinability are suitable for micro and precision fields due to their low coefficient of linear expansion, but both have the disadvantage of poor cutting. Therefore, it is decided to develop a kind of cast steel with low thermal expansion, which requires that its shear property be improved and can be made into castings with complex shapes, and its normal temperature linear expansion coefficient is below 4x/k. MNS and graphite are selected as the medium materials for free cutting. In order to cast the castings with complex shapes, the casting properties must be considered in the composition design. In order to maintain the low thermal expansion characteristics, a balance must be made in the basic composition, and the as cast micro segregation of the produced castings must be suppressed

v. automobile brake turntable made of heat-resistant aluminum composite materials

the automobile brake system is mainly cast iron, of which the turntable accounts for a large proportion. If aluminum can be used instead, it can be lightweight. However, after years of discussion, due to the problems of heat resistance and cost, it can only be used in some special vehicles. Therefore, the aluminum composite turntable made of ceramic magnetic preformed material is developed to achieve the purpose of wear resistance and improving heat resistance

in the past, when the rotary table was made of particle dispersed composite materials, the aluminum alloy dispersed in the liquid metal was first cast, so the whole rotary table was made of the enhancer. However, in this case, from the fluidity and dispersion of the aluminum composite molten material, the strengthening rate can only reach about 20%. The newly developed process method is to place the strengthening material at a fixed position in the metal mold, then pour the aluminum alloy melt and pressurize it. The strengthening material is permeated with aluminum alloy, and the strengthening rate can meet the requirements, and the required parts can be strengthened. This new product is a partially strengthened aluminum turntable strengthened only on the sliding surface. Considering the heat resistance, wear resistance and machinability, the strengthening rate is about 30%. The previous 400 ℃ increase in the strength of the rotary table is the heat-resistant limit temperature. For this newly developed product, no white lines are found when the temperature exceeds 500 ℃. Since there is no local softening, the enhancer falls off. However, when the temperature exceeds 500 ℃, the surface is rough and the friction coefficient decreases. In this temperature region, all the aluminum matrix softens. Therefore, this is the ultimate temperature of aluminum matrix composites

the heat resistance of this development is 100 ℃ higher than that of the past aluminum composite turntable. The braking performance test shows that the practical friction coefficient can also be ensured at 560 ℃, which can be adopted by general vehicles

VI. large cast aluminum wheel hub

the aluminum wheel hub of automobile has one-time forming of the overall structure, and also has two or three times manufacturing. The method is simple, and more than 90% of them are manufactured at one time. The size of the previously manufactured hub is less than 18 ″. The size of tires used for small trucks in the market should be 22 ". For the development of large aluminum wheel hub, the pouring casting method with large degree of freedom is adopted because the low-pressure casting method is limited by the molten filling method

in order to meet the needs of the market, the demand for large-diameter wheel hubs will increase, and as a safety part, 22 "wheel hubs will also increase for cars. After that, 23" and 24.5 "large-size aluminum wheel hubs will be developed on the basis of manufacturing 22"

VII. High strength and high ductility aluminum alloy die-casting thin-walled automobile suspension parts

due to the defects of die-casting parts such as air holes, shrinkage holes, poor pouring and hard spots, the parts requiring mechanical properties (especially ductility) were rarely used in the past, and the newly developed oxygen replacement method, laminar flow filling method, decompression method, semi-solid, casting and other methods can not completely solve the problem. New? quot; NIES "Nies method can mass produce castings with high strength and ductility, which can meet the requirements of suspension parts.

nies method is a system developed by Nissan company, which focuses on high strength and high ductility alloy and high vacuum casting machine. Its characteristics are: it can produce castings with high strength and high ductility that can be heat treated and welded. The main contents are as follows: 1. use vacuum pressure to quickly and quantitatively supply molten aluminum; 2. use heat insulation and demoulding lubricating materials to keep molten aluminum warm; 3. because of vacuum The degree of control to minimize gas entrainment; 4. the potential advantages of developing new alloys are great

this new technology has been used in the lower link of the rear suspension of Nissan's skyling sedan, reducing the weight by 23%

VIII. Production of Long Elbow steering gear by squeeze casting

squeeze casting has higher mechanical properties than other casting methods. This is because the metal casting liquid can be directionally solidified at the same time of high-pressure feeding molten liquid, so as to obtain the castings without holes and bubbles. It is a new Japanese  KY line4) ⑵ - amino ⑵ - deoxygenation- β- The technology of mass production has been developed for connecting the elbow steering gear used on the front suspension of D-glucan car. The elbow steering gear is about 600mm long, with two parts, an extended steering knuckle arm, an integrated upper arm and a lower suspension link. Its total length is about 3 times that of previous products, and its weight is 1.3 times. The contents of research and development include: 1 To ensure the fluidity of the casting liquid, the scheme that the temperature of the casting liquid is still high when it reaches the tip of the long upper arm is adopted through the fluidity analysis; 2. ensure directional solidification, and realize directional solidification of each arm position through solidification analysis; 3. shorten the operation cycle of the casting machine; 4. transform the existing casting equipment

IX. oil passage for casting engine blanks

diesel engines and oil circulation roads for agricultural tractors, generators and other industrial machinery used to be driven by 412mm and 260mm long drill bits, φ Therefore, there are processing time, accuracy, burr and other problems. Casting this kind of oil passage has been a subject studied for many years. Now it has been solved in sand core by using shell core. Thirdly, the sand is comprehensively studied, and the types of exhaust coatings, drying methods and transportation methods are studied one by one. There is no core support for the cast hole. In order to avoid deformation and fracture, oil will be supplied to the crankshaft neck φ The core is used as the outlet of the hole, and the residual sand in the oil duct is zero. The final process of cleaning is to sand blast the casting hole with a manual spray gun to make the residual sand zero. Check the cast hole with a special tool for confirmation before assembly

X. high strength cylinder head made by direct cold casting

in order to lighten the cylinder head, aluminum alloy is used. The cylinder head has cooling water path, intake and exhaust holes, etc., and its shape is complex. It also needs to be resistant to explosive pressure and high temperature durability. Especially for diesel engines with high compression ratio and severe service environment, the cylinder head must be made high-strength to ensure its durability

the strength of the casting is related to the material, casting process, heat treatment and other conditions. Firstly, the casting

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