论文部分内容阅读
利用金相、电子探针、扫描电镜及X射线衍射等手段对运行九年的乙烯裂解炉弯头的组织及损伤进行了研究。结果表明,在弯头底部渗碳较严重的部位,渗层内枝晶间碳化物呈条状分布,并有碎化现象,未渗碳区内二次碳化物的形态除颗粒状外,还有针状。弯头肩部及底部的龟纹状裂纹是由热疲劳与氧化相结合的腐蚀疲劳引起的。裂纹内壁的腐蚀产物是Cr_2O)3及(Cr,Fe)_3O_4。
The microstructure, damage of the cracked elbows in ethylene cracking furnace operated for nine years were studied by means of metallography, electron probe, scanning electron microscopy and X-ray diffraction. The results show that in the bottom of the elbow carburizing the more serious parts of the interdendritic carbide layer within the strip distribution, and the phenomenon of fragmentation, carburizing the form of secondary carbides in addition to granular A needle. Elongated shoulders and the bottom of the turtle-like cracks by thermal fatigue and oxidation combined with the corrosion fatigue caused. The corrosion products of the crack wall are Cr 2 O 3 and (Cr, Fe) 3 O 4.