The hottest new products, materials and processes

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 foundry industry must continuously improve 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, life and reducing costs) that cooperate with users. In addition, we 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 foundry industry is a very important link. All relevant parties 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 link in determining the rise and fall of Japan's exports. Due to the overall economic downturn, Japan's casting production 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 the display of new products in the first issue of each year, introducing the new products, new materials and new processes of various manufacturers. The new products related to casting published in the first issue of "plain materials" in 2002 are translated and introduced in order to attract the attention of all parties

I. ductile 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 of 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 easy 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. Equipped with the frame, there is also a nodular iron ball seat, which has the function of freely adjusting the anchor and angle

ductile iron frame drawing

technical indicators:

design mechanical properties

248kn~62kn

weight

330kg~700kg

compression area

1 3

schematic diagram of adjusting the fixed angle

II. Large stator pressing plate of Austenitic Ductile Iron

in order to improve the power generation efficiency of super large generator and simplify its structure, it is a good idea to use non-magnetic materials to make flanges that tighten the stator. In order to make the flange have the necessary strength and specific magnetic conductivity, and the internal and external quality meet the requirements, it is made of Austenitic Ductile Iron, but the manufacturing of this kind of casting has the following difficulties

◇ graphite and matrix structure are more sensitive to wall thickness than ash. Nanjing University of technology and others have been working on it since 2000 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

◇ Changkou like steel casting is required, which makes it more difficult to ensure the performance of the body

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

to ensure the integrity of the macro structure, no internal shrinkage cavities and surface wrinkles are allowed. It is easy to produce massive graphite and carbides when the wall thickness part solidifies. This tendency will be stronger in the riser part due to the slower cooling. This is the main reason for the deterioration of the strength and specific permeability of the whole casting; Keep single when as cast γ The phase is difficult, and heat treatment must be carried out. In order to ensure the strength and specific permeability of the body and prevent 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 tight stator: 130mm, weight as cast: 7000kg

III. double layer cylinder liner for high-speed diesel engine - the combination of long size double-layer casting technology and special surfacing design

thin wall cylinder liner with small caliber for high-speed diesel engine adopts the blank of long size cast double-layer tube to realize lamination. The outer layer is made of high-strength cast steel, which has high strength and high reliability. The inner layer is made of high phosphorus cast iron, so as to ensure that the historical special EBIT (excluding special items) of sliding wear is 1.331 billion euros. It is formed by centrifugal casting and adopts special double-layer pipe casting technology to completely integrate the inner and outer layers. The inner diameter of the cylinder liner is 280, the maximum outer diameter is 390, and the length is 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 designing the surfacing conditions, control its thermal influence to have a bad effect on the double-layer blank tube

IV. low thermal expansion cast steel with good machinability

invar alloy and super invar alloy 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 cast steel with low thermal expansion, which requires the improvement of its shear property 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 intermediate materials for free cutting. In order to cast castings with complex shapes, its casting properties must be considered in its composition design. In order to maintain the low thermal expansion characteristics, a balance must be made in the basic composition, and the produced castings must suppress the micro segregation of the as cast state

v. turntable for automobile braking made of heat-resistant aluminum composite

the braking system of automobile 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, 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 due to the enhancer, but in this case, according to the fluidity and dispersion of aluminum composite molten materials, the strengthening rate can only reach about 20%. The newly developed process method is to place the strengthening material in a fixed position in the metal mold, pour the aluminum alloy melt and pressurize it. The strengthening material is permeated with aluminum alloy, and the strengthening rate can meet the required characteristics, 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 selected at 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 it 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, so this is the limit 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 used by general vehicles

VI. large cast aluminum wheel hubs

aluminum wheel hubs of automobiles have an overall structure formed at one time, and are also divided into secondary and tertiary 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 hubs, due to the limitation of molten filling method by low-pressure casting, the dumping casting method with large degree of freedom is adopted

in order to meet the needs of the market, the demand for large-diameter wheels will increase, and as a safety part, 22 "wheels will also be used in cars. After that, 23" and 24.5 "large-size aluminum wheels 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 shortcomings of die-casting parts such as pores, shrinkage, poor pouring and hard spots, 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 takes high strength and high ductility alloy and high vacuum casting machine as the center. Its characteristics are: it can produce castings with high strength and high ductility that can be heat treated and welded. The main contents are: 1. Use vacuum pressure to make aluminum liquid supply quickly and quantitatively; 2. Use heat insulation and demoulding lubricating materials to keep aluminum liquid warm; 3. Because of vacuum The degree of control to minimize the involvement of gas; 4. There are great potential advantages in developing new alloys

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

VIII. Using squeeze casting to produce long-size elbow steering gear

using squeeze casting, the mechanical properties of the casting are higher than those of other casting methods. This is because the metal casting liquid can be directionally solidified at the same time of high-pressure supply of molten liquid, so as to obtain castings with fine crystals 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. This 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 the 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 duct 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 of discussion for many years, and 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 gun to make the residual sand zero. Check the cast hole with special tools for confirmation before assembly

X. make high-strength cylinder head 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 has 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

strength and material of castings, casting