脱蜡工艺对超细预合金胎体中碳氧含量的影响

Effect of dewaxing process on carbon and oxygen content in ultra-fine pre-alloyed matrix

为提高超细预合金粉末的流动性、冷压性能,需加入制粒剂对超细预合金粉末进行制粒,再通过还原脱蜡工艺和随炉保温脱蜡工艺2种脱蜡方法去除。结果表明:超细预合金粉末制粒后无论采用还原脱蜡工艺还是随炉保温脱蜡工艺脱蜡,烧结后的胎体都会有制粒剂残留从而使碳含量增加;还原脱蜡工艺处理的胎体中碳、氧质量分数最低,分别为0.048%和0.22%,但随炉保温脱蜡工艺通过延长保温时间,胎体中碳含量也可以达到还原脱蜡工艺的水平。在随炉保温脱蜡工艺下,试样氧含量不随保温时间增加而降低,只与烧结条件有关,高温烧结时石墨模具内产生还原性气氛使试样氧含量降低。2种脱蜡方法对超细FeCoCu预合金粉末胎体的抗弯强度和洛氏硬度影响不大。

In order to improve the fluidity and cold pressure performance of superfine pre-alloyed powder,granulating agent should be added to the granulation of superfine pre-alloyed powder,and then the granulating agent is removed by reduction dewaxing process and heat preservation dewaxing process.The results show that no matter which dewaxing process after granulation,there will be granulating agent residues in the matrix after sintering,which will increase the carbon content.The mass fraction of carbon and oxygen in the matrix is the lowest in the reduction dewaxing process,which are 0.048%and 0.22%respectively,but the carbon content in the furnace preservation heat dewaxing process can also reach the level of the reduction dewaxing process by increasing the heat preservation time.In the process of heat preservation and dewaxing of the furnace,the oxygen content of the sample does not decrease with the increasing of the holding time.It is only related to the sintering condition.The reduction atmosphere in the graphite mold at high temperature makes the oxygen content of the sample lower.The two kinds of dewaxing methods have little effect on the flexural strength and Rockwell hardness of the superfine FeCoCu pre-alloyed powder matrix.