文献类型：期刊文献

英文题名：Analysis of failed electron beam welds in ethylene cracking tubes

作者：Guan, Kaishu[1];Wang, Qiangqi[1]

机构：[1]E China Univ Sci & Technol, Key Lab Safety Sci Pressurized Syst, Minist Educ, Shanghai 200237, Peoples R China

年份：2011

卷号：18

期号：5

起止页码：1366

外文期刊名：ENGINEERING FAILURE ANALYSIS

收录：;EI(收录号：20112114000129);WOS:【SCI-EXPANDED(收录号:WOS:000291905500012)】；

语种：英文

外文关键词：Electron beam weld; Ethylene cracking tubes; Cracking; Niobium-depletion

摘要：The occurrence of cracks at the electron beam (EB) welds of ethylene tubes in radiant chambers after 1-2 years in service has led to serious concerns. Failure analysis of the sample using optical microscopy, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) clearly reveals a centerline with dendritic crystals and blocky precipitates present at the welds, where the cracks occurred. Niobium-depletion at the EB weld centerline is mainly responsible for the carbide precipitates and cracks. Operation processes such as frequent start-stop cycling accelerated the cracks. (C) 2011 Elsevier Ltd. All rights reserved.