Optimization Of Gating And Riser System For Large Valve Body Investment Castings And Database Development Of CAPP System

It is difficult for large valve bodies castings due to their higher performancerequirements and the demand of withstand high pressure and high temperature, whichdetection means including water pressure testing or magnetic particle inspection etcare used to ensure their dense organizations without any casting defects such asshrinkage, porosity, cracks.Reasonable design for gating and riser system of valvebody investment casting is the key factor to ensure the quality of the valve andprevent their casting defects. Traditional design is worked through trial-and-errormethod which is time-consuming, production-costly and hard to control the quality.Adopting traditional design method of gating and riser system for large valve bodyinvestment castings is time-consuming, production-costly and hard to control thequality.The use of CAPP for gating and riser of large valve body investment castingsmake it possible to apply computer technology to investment castings industry,whichnot only automatize,standardize,informationize,the gating and riser design,but alsoeffectively improve the casting quality, shorting design cycle and reduce productioncosts.Therefore the development of CAPP for gating and riser of large valve bodyinvestment castings has important theoretical significance and practical value.Using ProCAST to simulate and optimize the large valve investment castingprocess aim at the defects such as shrinkage porosity in investment casting valvebodies. It has achieve bottom-up sequence solidification and eliminated the shrinkageporosity defects by adopting optimal four-top-runner-riser-intergrated-system;Building database for gating and riser of valve investment casting on SQL SERVER2000according to its optimal process system and design rules;Developinghuman-computer mutual interface based on VC++and using ADO dynamic links todatabase which can add,modify and delete informations;Calculating processparameters of gating and riser system for large valve body investment castingsincluding machining allowance,shrinkage,and sectional areas by interactive waycombine with the process database and optimized process system.Optimization of gating and riser system for large valve body investment castingsand development of its CAPP database is of great significance that optimal gatingand riser system was obtained and process database was established which not only realize the automation,standardization and information but also improve theefficiency, accuracy,consistency of pouring system design for large valve investmentcasting.In a word,optimization of gating and riser system for large valve bodyinvestment castings and development of its CAPP database provide guidance onprocess and technology for the investment casting of similar large valve.