Improvement Character Of Air Flush Molding Green-Sand

It is an economical and effective method to produce steel castings with green-sand air impact molding technology. The steel castings for rolling stock are needed in great batch and few variety, thus it is easy to manage production in series. Green-sand is easy to prepare by mixing and needs no treatments after formation. It can be poured immediately after core setting. Green-sand belongs to high density molding as shoot squeeze and static pressure such high pressure molding. It is powered by compressing air to mold in a moment. Comparing with the traditional molding technology, the sand mold is with a high moistening pressure and a even distribution of hardness. Thus the castings from green sand mold is with precise dimension, smooth surface and compaction organization. The mechanical behavior and the production rate are improved. The working conditions are improved. The air flush molding has a better distribution of hardness than ordinary high pressure molding. The part near to model is with a high hardness and the back part is with a low hardness. The sand mold is with a good conceding performance. What more, the green sand mold needs simple equipment and is very flexible to operate. The power price is very low. Thus, the future of the development and application of green-sand mold is very prosperous. Molding sand is very important to casting's quality. Through the research on the specific object, the characters of green-sand is expected to be improved. The research paper intends to develop the advantages of air flush molding and reduce the casting defects: blow hole, sand fusion, sand cut, swelling, sand inclusion and deforming. The whole research is divided to 2 parts: a researching test shall be performed at first, in order to confirm basically the feature parametes that the molding sand should achieve. Then, add respectively new sand, bentonite, amylum, MD powder, and check the features for the molding sand to finalize the element of the additives added. Secondly, on basis of exploring experiment, do the normal experiment to select the chemical composition. This research mainly explores the production of steel castings with air flush molding green sand and the improvement of its character from the molding sand recipe and mold sand system control. The high density green-sand molding has a high requirement for materials quality. First find the different influence brought by their physical and chemical characters to the molding sand workmanship character by inspecting the characters of some kinds of original sand, betonies, and grain attachment. The influential factors of mutual component shall be found. The original materials and molding sand character shall be systematically experimented to finish the improvement of original material. Particularly the quartz content, the liquid limit of clay soil shall be inspected. By inspecting the liquid limit, the proper activation amount is defined. The moist heat pulling intensity and the moist pressure intensity shall be measured and the influence curve line will be drawn. The multiple-use character of betonies will be analyzed with differential thermal analysis curve, in result of great experiment data and experiment have been accumulated. In additional, it is found that when selecting the green-sand materials, the domestic material quality and transportation should be considered. The domestic high pressure molding application situation will also be fully considered. On the basis of domestic material and the requirements of molding sand, the experiments of green-sand air flush molding recipe will be made and the improvements of molding sand match will be finished. Associated with the situation of my manufacture, the general character of green-sand is improved by researching the compound betonies mixed with variety of materials to ensure that the materials is mixed evenly and eliminate the classification of feeding which causes the uneven hardness distribution and serious defects. Second, the effective management and control of molding sand system will be improved to improve the molding sand'character. Finally, by comparing the pouring casting substances, the casting defects such as sand fusion, sand cut, and sand inclusion are solved and the quality of products is improved.