A Basic Study of Developing Refractory Metals for Waste Burner

开发垃圾焚烧炉用难熔金属的基础研究

基本信息

批准号：
04650642
负责人：
HARA Motoi
金额：
$ 1.15万
依托单位：
Akita University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1993
项目状态：
已结题

项目摘要

High temperature corrosion behaviors of various metals were examined in an atmosphere including HCI by a thermogravimetric apparatus.For pure Fe, the corrosion rate at 700ﾟC in the atmosphere including HCI was higher than that in pure O_2. However, the corrosion rate above 900ﾟC was lower in the atmosphere including HCI in spite of the formation of a volatile FeCl_2. These phenomena were due to the simulaneous progress of oxidation and chlorination of Fe.For pure Cr. the formation of Cr_2O_3 was tremendously accelerated in the temperature region from 750ﾟC to 850ﾟC in the atmosphere including HCI.However, in the other temperature region the corrosion rate was almost the same as that in pure O_2. These were thought to be attributed to the fact that the formation of CrCl_2 playd an important role on the corrosion behavior.For pure Ni, the corrosion proceeded with a decrease in mass of the specimen due to the fotmation of a volatile NiCl_2 at the temperatures from 700ﾟC to 1000ﾟC in the atmosphere including HCl. A thin NiO scale layr was observed on the specimen after the test. The corrosion rate in an 1%HCl atmosphere was higher than in pure O_2. These suggested that the corrosion in the atmosphere including HCI was attributable to both oxidation and chlorination of Ni.For Fe-Cr alloys, the corrosion rate in an 1%HCl atmosphere was decreased with an increase in Cr content. For the alloys containing several percent Cr, however, the corrosion rates were higher than those in pure O_2. It was revealed that elemental Cr was concentrated in the scale around the metal/scale interface. Therefor, such higher oxidation resistance for the Fe-Cr alloys was due to the formation of Cr_2O_3 film at the metal/scale interface.

利用热重分析仪研究了各种金属在含HCl气氛中的高温腐蚀行为。对于纯Fe，在含HCl气氛中700℃时的腐蚀速率高于纯O_2中的腐蚀速率，但在900℃以上时腐蚀速率较高。尽管形成了挥发性的 FeCl_2，但在包括 HCl 在内的大气中，C 仍然较低。这些现象是由于 Fe 的氧化和氯化同时进行所致。 Cr.在含有HCI的气氛中，在750℃到850℃的温度范围内，Cr_2O_3的形成极大地加速。但是，在其他温度范围内，腐蚀速率几乎与纯O_2中的腐蚀速率相同。归因于 CrCl_2 的形成对腐蚀行为起着重要作用。对于纯 Ni，腐蚀随着样品质量的减少而进行，这是由于在含HCl的气氛中，在700°C至1000°C的温度下，会形成挥发性NiCl_2。试验后，在样品上观察到薄的NiO氧化皮层，在1%HCl气氛中的腐蚀速率高于在纯HCl气氛中的腐蚀速率。 O_2。这表明，在含有 HCI 的大气中的腐蚀可归因于 Ni 的氧化和氯化。对于 Fe-Cr 合金，在1%HCl气氛中Cr含量随着Cr含量的增加而降低，然而，对于含有百分之几Cr的合金，腐蚀速率高于纯O_2中的腐蚀速率。结果表明，元素Cr集中在金属/氧化皮周围的氧化皮中。因此，Fe-Cr合金具有较高的抗氧化性是由于在金属/氧化皮界面处形成了Cr_2O_3薄膜。