高强度灰铸铁皮带轮的生产工艺

Production Process of High Strength Gray Iron Pulley

介绍了大型皮带轮的铸件结构及技术要求,详细阐述了该铸件的生产工艺:采用3 t中频感应电炉熔炼铁液,炉料配比为20%废钢屑压块+40%废钢块+20%HT250铁屑压块+20%回炉料+2%增碳剂+0.6%FeSi+0.6%FeMn;铁液过热到1 550℃,断电静置3～5 min,铁液出炉温度为1 450～1 500℃;采用包内冲入法进行孕育处理,孕育剂加入量为0.60%～0.80%,浇注温度为1 360～1 400℃。生产结果显示:A型石墨占90%以上,石墨片细小、弯曲,基体中珠光体体积分数达到93%～95%;抗拉强度达到278～310 MPa,硬度达到182～210 HB,符合技术要求,降低了生产成本。

The structure and technical requirements of large belt pulley castings were introduced,and the production process of the castings was described in detail:molten iron was melted in a 3 t medium frequency induction furnace,the melting charges were consisted of 20% steel scrap briquette+40% steel scrap block+20% HT250 gray iron chip block+20% foundry returns+2% carburetant+0.6% FeSi+0.6% FeMn,the molten iron was superheated to 1 550 ℃,power was cut off,molten iron was held in furnace for 3~5 min,tapping temperature was of 1 450~1 500 ℃,inoculation was carried out in the ladle with pour-over process,the inoculant amount was of 0.60%~0.80%,pouring temperature was in the range of 1 360~1 400 ℃. The production result showed:A-type graphite was more than 90%,the graphite flakes was small and curved,the volume proportion of pearlite in matrix reached 93%~95%,tensile strength reached 278~310 MPa,the hardness reached 182~210 HB,meeting technical requirements and reduce production cost.