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我厂主要生产中小口径(DN3～150mm)的高、中压铸钢阀门。在生产过程中,我们发现,铸钢阀门热裂缺陷较为严重,影响了生产的进程。为此,我们进行了研究和分析,认为阀门铸件产生热裂缺陷的原因有以下几方面:打箱与水爆清砂过早;型砂特别是芯砂干强度过大而造成退让性差;冷铁设置不当所产生的阻碍收缩;铸件分型面飞边过多、过厚;钢水中硫、磷含量偏高;热处理工序不当等。
I plant mainly produces small and medium caliber (DN3 ~ 150mm) of high and medium pressure cast steel valves. In the production process, we found that the hot cracking defects of cast steel valves are more serious, affecting the production process. To this end, we conducted a study and analysis, that valve casting hot cracking defects due to the following reasons: boxing and water blasting too early sand; sand, especially the core sand dry strength is too large, resulting in poor concessions; cold iron set Improper obstruction caused by shrinkage; cast parting surface too much flash, too thick; molten steel sulfur, phosphorus content is high; improper heat treatment processes.