铸铁件打箱时间设计的影响因素研究

Study on the Influence Factors of Iron Casting Knockout Time Design

针对铸铁件打箱时间设计的影响因素,从凝固时间、组织结构转变、冷却速率、材料的高温性能进行了研究,并给出了铸铁件打箱时间设计的原则和方法,提出以下建议:(1)须在铸件完全凝固后再考虑移动铸件,完成凝固时间可以根据经验公式进行估算;(2)为保证铸件基本性能,须等到组织转变完成后再考虑打箱,对于铸铁件,不建议高于550℃打箱;(3)铸铁件高温打箱时,须设法避免铸件发生较大受力或撞击;(4)对于结构复杂、壁厚差异大的铸件,须进行炉内热时效处理才能发货,对于不进行热时效的铸件,球墨铸铁件不建议高于300℃,灰铸铁件不建议高于200℃打箱。

The influence factors of iron casting knockout time design was studied including solidification time,microstructure transformation,cooling rate and high temperature properties. The following recommendations were proposed:(1)The movement of the casting should be considered after the casting had been completely solidified,the complete solidification time could be estimated according to the empirical formula.(2)In order to ensure the basic properties of the castings,the knockout should be considered after the completion of the transformation of the microstructure,for the iron castings,it was not recommended to knockout above 550 ℃.(3)When the cast iron casting was knockout at high temperature,efforts should be made to avoid greater force or impact on castings.(4)For the castings with complex structure and large difference in wall thickness,heat aging treatment must be carried out in the furnace before delivery could be made. For castings without thermal aging,nodular iron castings were not recommended to be knocked out at temperature higher than 300 ℃,and gray iron castings were not recommended to be knocked out at temperature above 200 ℃.