The smelting equipment is a 0.51 coreless induction medium frequency furnace, equipped with rapid test equipment in front of the furnace, regularly pouring samples for performance inspection and modeling, 32 water glass hardened sand, cast aluminum pattern and core box. Modeling process The casting material is accurate in size, high in strength, and good in air permeability, brass gear Manufacturers avoiding damage during the process of lowering the core. Gold steel, the casting stress is large, and the casting is easy to crack. Therefore, the runners should be more and scattered, and the runners should be opened along the ribs. The casting has local thermal joints, and a feeder riser needs to be set up. In order to improve the riser shrinkage efficiency, an atmospheric pressure riser is used to ensure that there are no shrinkage and shrinkage defects in the casting. The core-down method uses a split die to make the appearance of the casting, and then assembles the core. In the lower core sequence, firstly insert 7 cores into 4 cores of 61 cores, and 8 cores into 4 cores to form two integrated cores. Then the direction is based on the shape of the casting, and the core head is used for positioning. The width direction is based on 1 core. Position with a core brace. This can not only ensure the accurate size, but also easy to operate and inspect. According to the casting structure, the core shape is adopted, 32 water glass hardened sand. The two sides of the casting are 4 and 5 sides, and the perpendicularity is 2.5mm. The mold tilt is not allowed.
Therefore, the splitting process is used to ensure the verticality and facilitate the mold lifting. 23. Sand core design The casting structure is more complex and geometric Strict size requirements, especially the 6-shaped through slot meaning 1. Draft angle 2. Pattern 3. Sand 4. Sand box. The parting line l is required to have a flatness of 4 on each side of the 3 split die model within a length of 1500 mm and means a non-machined surface. Here, the sand core must be made as a whole to ensure accuracy, and the other cavities of the casting are made in blocks. To ensure the accuracy of the sand core, the core box is made of cast aluminum and is machined. The sand core is made of water glass sand, blown, and then lifted from the mold. In this way, the sand core 3. Casting defects and solutions During the initial trial production of the casting, there have been casting defects such as bending deformation cracks and sticky sand. We analyzed and found For some reasons, after adopting a series of technological measures, the casting defects were resolved and satisfactory results were achieved. 1 Bending deformation castings, if the surface is subject to bending deformations, the 5.0 surface deformation is caused by the cooling speed does not cause the core thickness to be large, and the heat dissipation is slow. The 23 plate increases the heat dissipation area and the cooling rate is faster, so that the surface generates tensile stress. A concave surface is generated, and the opposite surface is raised by compressive stress. The technological measure to eliminate deformation is to make a 58mm reverse deflection on the 1-core box, which is intended to stop the intermediate frequency electric furnace. The small curved door is sometimes caused by operation during the manufacturing process of the intermediate frequency induction furnace. Heap accidents appear to be misaligned or hit. Phenomenon misalignment refers to the increase of mischief caused by deviation from or higher than the original place. In order to prevent this, in addition to the accurate position of the crucible when the weight of the iron is reasonable, the force of the beating is evenly distributed when the furnace is beaten. At the initial stage of the crucible, it should be noted that the position of the crucible is often observed and adjusted. This article introduces a tip for your reference. Put people in, adjust the position, press with iron, and take the distance between the crucible mold and the aluminum work platform. Crucible position inspection, meaning 1. Aluminum work platform 2. Induction 3. Crucible molds are often measured with a tape measure or 6 iron wires during the initial stage of the crucible mold.
When the change occurs and becomes, compare, and, 6, you can observe the changes in the wall thickness of each part of the crucible in time, and check that the deviation direction and size of the crucible from the original position at this time are compared with 6 and It reflects that the crucible is now skewed to the right and deviated from this distance. When the crucible is hit, the inspection using this method can timely reflect the distance from the original position in the vertical direction in order to take corresponding crucible adjustment measures to correct the crucible. For more accuracy, you can also take a few more measurements between the aluminum work platform and the crucible mold to verify each other. The best time to adjust the position of the crucible is at the beginning of making. Checking and adjusting the position of the crucible in time is effective to prevent the crucible from deviating to offset the deformation of the casting, which is very effective. When the surface 1 moves under the seat, sometimes cracks occur, and the length is curved. It belongs to thermal cracking 6, which indicates that the cracks have formed at the high temperature of liquid-solid transition. The casting has 5 large sand cores in the length direction, which severely hinders the shrinkage of the casting. The strength of the casting that has just solidified at low temperature is low, and it is easy to crack under the effect of stress. For this reason, in the casting parent 40, there are two crack prevention ribs. 7. The crack prevention ribs are removed after the casting is annealed. After the anti-crack rib was added, no cracks occurred in the casting. After ultrasonic inspection, the cracks were completely eliminated.
The sticky sand casting often has severe sticky sand at the root of the 0-shaped groove and at the two long holes of the sliding seat. Here, the sand core is wrapped in warm steel liquid for a long time. In addition, the size of the sand core is smaller than 20, and the sharp corner effect occurs, which is easy to produce mechanical and chemical sticky sand. The solution to the process of sticking sand is to thicken the coating thickness there and increase the fillet of the sand core. , Use limestone sand 03 instead of quartz sand. After the test, the sticky sand defect has been greatly improved, especially the limestone sand. The casting grooves are very smooth and worthy of popularization and application. There are two 45mmX55mm recesses in the casting, which are non-machined mating surfaces. During the initial trial production, there was serious sticky sand here, and there was almost no way to clean it up, and some of the sticky sand caused scrapping of the casting. For this we have designed a shaped cold iron. When making the core, it is embedded in 5 cores, which is equivalent to local metal mold casting. This method is very effective. Not only is casting iron a good way to solve local sticky sand. A total of 45 coal fenders, which were cast in accordance with the above process, totaled 45 pieces, and after inspection by relevant departments, they all met the technical requirements. After dissecting the casting, the internal tissues are dense and there is no shrinkage. The load test was performed under the rated pressure, and the casting did not yield or break. Practice has proved that this process is reasonable and feasible, and the technological measures taken are effective.
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