管用20钢冶工程毕业设计.docVIP

摘 要 近年来随着冶金行业的迅猛发展，事故也时有发生，对人民生命财产安全造成极大危害，其中高压管失效甚至爆炸导致的事故也时有发生。高压管道在冶金行业中的主要应用就是转炉余热锅炉的集气烟道等部件，据统计全国约百分之80的转炉都配有余热锅炉。本文以取自鞍钢集团鲅鱼圈分厂的失效的20G余热锅炉管道为样品，制备成金相观察试样后通过金相显微镜进行金相观察，分析其裂纹和金相组织，通过查阅大量文献资料比对裂纹形式，生长情况，及裂纹周边组织以及对试样的使用环境进行详尽的了解，采用微观与宏观相结合的综合分析得出了热疲劳，材料中非金属夹杂以及生产工艺达不到技术要求等为20G在使用过程中失效的原因。在20G使用过程中应尽量克服以上失效原因以延长余热锅炉等部件的使用寿命，确保生命财产安全，增加经济效益。 关键词: 管用20钢；余热锅炉；集气烟罩；失效原因 Abstract With the rapid development of metallurgical industry in recent years, the accidents occurred much frequently, and it makes great harm to the lives and property security of people. And the accidents that the high-pressure pipe failure even explosion have occurred sometimes. What high pressure pipe mainly used in metallurgical industry is the collecting-gas flues of the heat recovery boiler in the converter. According to statistics, about eighty percent of the converters are equipped with a heat recovery boiler. This paper takes the failed 20G pipe of the heat recovery boilers collected from Ba Yu Quan branch of ANSHAN IRON AND STEEL GROUP CORPORATION as an example, makes it a metallographic observation sample, carries out the metallographic observation under the metallographic microscope and analyze its cracks and the microstructure. By looking up a large number of literatures to compare the cracks’ forms, growth, and the peripheral tissues around the cracks and get a detailed understanding about the operational environment of the sample. By the comprehensive analysis with the combination of micro and macro, it comes to get the reasons why 20G fails in the process of using that are thermal fatigue, the non-metallic in the materials and production process’s failure to meet the technical requirements, etc. Thus, in the process of using 20G, it is necessary to overcome the above failure reasons so as to prolong the service life of the heat recovery boiler and the other parts, to ensure workers’ lives and property securities and to increase the economic benefi