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过去,我厂生产的钨系合金铸铁活塞环,尽管铁水的化学成分符合要求,但由于孕育工艺不当,活塞环边角常出现局部白口和针孔,给活塞环在机加工时造成了较大困难。近来,我们改善了孕育工艺,有效地防止了针孔、局部白口等缺陷的产生。1.采用瞬时孕育工艺,可以降低铁水在凝固过程中的过冷度,减缓活塞环因薄壁而产生白口的倾向,从而有效地消除铸件中的游离渗碳体。将孕育剂的粒度控制在1～4mm。严禁使用过筛后的硅铁粉面,以免加入后因铁
In the past, the tungsten alloy cast iron piston rings produced by our factory, although the chemical composition of the molten iron met the requirements, but due to improper inoculation process, the white ring and pinholes often appear at the corners of the piston ring, Big difficulty. Recently, we have improved the inoculation process, effectively preventing the occurrence of pin holes, local white defects and other defects. 1. The instantaneous inoculation process can reduce the overcooling of the molten iron in the solidification process and reduce the propensity of the piston ring to produce a white mouth due to the thin wall, so as to effectively eliminate the free cementite in the castings. The inoculant size control in 1 ~ 4mm. Prohibited the use of sieved ferrosilicon noodles, so as not to join after the iron