Development of Rapid Sintering Technique on Metal Powder by Considering the Saving Energy and Environmental Pollution Plan

本研究的目的是利用高频加热仪进行快速烧结，并与常规烧结炉进行比较。几分钟内快速烧结技术就是研究2种钢(碳素钢和高强度合金钢)。研究气氛转变为真空、氮气和氮氢三种类型。结果表明：1真空条件下碳钢粉末颗粒表面吸附气体的去除和各粉末的扩散与烧结是一个非常重要的因素。烧结过程中的等温处理是本实验中的一项关键技术处理。该方法只需3分钟即可完成烧结，其条件为：最大加热时间-30 S，烧结条件为1523K-60 S，等温处理-90 S，在氮气气氛下只需2箱碳钢。在氮气气氛下，铁粉…中的吸附气体的释放是很重要的更多的r粒子面。由于力学性能的降低，试件表面脱碳层的生成是一个问题。该方法烧成仅需3.5min，径向抗压强度(RCS)与常规炉法基本相同。3碳钢在氮氢气氛条件下，加入低浓度的氢气从1%到2%，RCS和防止脱铬与100%氮气气氛快速烧结的RCS几乎相同。这种RCS下降的趋势是由于H2气体的存在而形成FeOOH化合物，这种化合物阻止了铜元素的扩散。4真空条件下高强度合金钢的快速烧结需要控制额外合金元素的脱气和扩散，并在基质中形成马氏体或贝氏体组织，这是烧结过程中非常重要的因素。可以理解，与传统的炉法相比，该烧结工艺需要最高的烧结温度，但通过改变保温时间获得了相对较高的RCS。尽管高强度合金钢需要更长的时间来扩散额外的合金元素，但该过程只需3~4min的保温时间。较少

This research was purposed by rapid sintering process used the high frequency heating instrument that compared to conventional sintering furnace. Rapid sintering technique within a few minutes is to investigate 2 types of steels (carbon steel and high strength-alloyed steels). And, the research atmosphere changed to 3 types of vacuum, nitrogen and nitrogen-hydrogen. The results were obtained as follows.1 Case of carbon steel under vacuum conditionThere is very important factor both the removal of adsorbed gas in powder grain surface and accompanied by the diffusion and sintering of each powder. The isothermal treatment when the sintering process in this experiment was a key technology treatment. This method was finished to sinter only 3 minutes, and it's condition was maximum heating time-30 s, sintering condition 1523 K-60 s and isothermal treatment-90 s holding only.2 Case of carbon steel under nitrogen gas atmosphere conditionIt was important to release an adsorbed gas in iron powde … More r particle surface. The product of decarburized layer on specimen surface was a problem because of reduces of mechanical properties. This method was finished to sinter only 3.5 minutes, and the radial crushing strength (RCS) was obtained almost same value compared to conventional furnace method.3 Case of carbon steel under nitrogen-hydrogen gas atmosphere conditionIn the case, added low H2 gas concentration from 1 to 2 %, RCS and prevention of decaburization were almost same values compared to rapid sintering of 100 % N2 gas atmosphere. This lowering tendency of RCS was caused to form FeOOH compound by the present of H2 gas and this compound prevented to diffusion of Cu elements.4 Case of high strength-alloyed steel under vacuum conditionThis rapid sintering needs to control the degassing, diffusion of additional alloying elements and form a Martensite or Bainite structure in matrix and these are very important factor for the sintering process. It can be understood that this sintering process needs the highest sintering temperature compared with conventional furnace process but obtained comparatively higher RCS by changing the holding time. This process took only 3〜4 minutes for holding time, in spite of high strength-alloyed steel required longer time for diffusion of additional alloying elements. Less