【摘要】 针对索菲姆发动机高磷铸铁气门导管生产中出现的金相组织不符合要求的内在质量问题，在对该发动机气门导管原件和现生产工艺分析的基础上，改进了导管的生产工艺，加强了生产的炉前工艺控制，使其金相组织和性能达到了技术要求。更多还原

【Abstract】 In light of the poor quality in production of high - phosphorous iron valve guides for SOFIM automotive engine, the microstructure of both imported and self- made valve guides is examined and of both imported and the production processes are analysed. Based on these works the manufacturing processes of valve guides have been improved, the process control upon the spot is strengthened. After all the microstructure and properties of valve guids have met the technical requirements.更多还原